RO128995B1 - Process and installation for extracting gold, silver and other accompanying metal or non-metal elements from rosia montana and other similar ore deposits - Google Patents

Abstract

The invention relates to a process and an installation for extracting gold, silver and other accompanying metal and non-metal elements from the Rosia Montana or other similar ore deposits. According to the invention, the process consists in conveying the ore (1), fluorspar (2), quartzite (3), bauxite (4) and magnesite (5) into some work bunkers, wherefrom they are subjected to some preparation operations consisting in sorting them on grates, crushing and sorting according to the granulometric sizes, afterwards there being performed the burning of the sulphur in the ore having a granulation smaller than 3 mm, at a temperature of 750...800°C and the briquetting of the desulphurized and granulated ore, respectively, then there is carried out the smelting of the gold, silver and, possibly, copper, in an arc furnace, followed by a discharging into a ladle, with plug or drawer closing, wherefrom the smelt is sent into a casting assembly, and on, after the metal solidification, the ingots being subjected to electrolytic refining of gold, silver and other possibly accompanying metals, in the conditions when the slag obtained when smelting gold and silver is used as electrolyte, the electrolyte being smelt in an arc furnace, the fluorspar, quartzite, bauxite, magnesite and the caustic lime being used as fusing agents. As claimed by the invention, the installation comprises at least a multi-level furnace, where the levels inter-communicate from the top downwards, a mixer with horizontal axle and with blades, a die (3) and a carrousel-type mechanized press, as well as an arc furnace, a ladle, a casting assembly and an arc furnace for electrolysis.

Description

Everyone has the right to make in writing and motivated, at OSIM, a request for revocation of the patent of

The invention, within 6 months from the publication of the mention of the decision granting it

RO 128995 Β1

The present invention relates to a process and an installation for obtaining gold and silver and other metallic and non-metallic accompanying elements from the Roşia Montană deposit and from other similar deposits.

At the world level, at present, for most of the gold-silver mines, the cyanide process is applied, in others the amalgamation process and in others the two combined processes.

Both processes are toxic and can affect the human body, but the most toxic and unimaginable consequences is the first procedure.

Research is being carried out in all the industrialized countries, possessing gold-silver deposits, to replace the cyanide process, but most of them are in the laboratory phase.

Also, there is known a process and an installation for extracting and separating useful components, from thermal ash, sterile ash and the like (RO 120047 B1).

The known process consists, in a first phase, of melting at a temperature of

1550 ... 2000 ° C of the ore, after which the melt is introduced into a separation plant, by centrifugation, in which an acceleration of up to 1500 m / s ² is printed to the components. After centrifugation, the melt separates according to the densities of the components, as follows: at the periphery of the inner enclosure, precious metals such as gold and silver, platinum, tungsten, etc., accumulate in toroidal pockets. The next relatively vertical layer contains a liquid component with over 95% iron oxides, which is discharged at the bottom of the installation, after which another, less dense liquid component, consisting of a mixture of aluminum oxides, is separated and accumulated. and silicon, and on the axis of the installation, a mixture of calcium oxides, magnesium silicon etc., separated, is evacuated, through the separate channels, on the outside (RO 120047 B1)

The known installation consists of an interior enclosure, surrounded by a refractory masonry and a metal casing, involved in rotational movement. At the top, under a power connection, a dispersion element is fixed, and at the periphery of the inner enclosure, there are toroidal pockets in which precious metals accumulate. The liquid components, separated in relatively vertical layers, clearly delimited at the bottom, are discharged to the outside, through exhaust channels and an axial connection, practiced in a fixed part of refractory material (RO 120047 Bl).

The present invention resolves, originally, the obtaining of gold and silver, and is definitely superior to the above processes, in that the process consists in the first phase of ore crushing and sorting; from the waiting bunkers it passes into automatic dispensers with gravimetric system with a weighing tape and then they are passed into a dispenser trolley, from which it is discharged into a pivot which is placed on the platform of a trolley and is guided under the crane hook, which supports the yoke with the two hooks and is raised by the hooks of the yoke and directed to the bunker with granulated ore supply of a furnace, where the sulfur is burned at temperatures of 750 ... 800 ° C, and from the limestone deposit, the limestone with the granulation between Φ 60 and Φ 80 mm is brought to the limestone burning furnace, on conveyor belts, where with the aid of a skip, it is charged to the top of a furnace that is heated with methane gas, at a temperature of 1250 ° G, in the area burners, so that when the limestone is lowered in the oven, it is dissociated, after which the burned lime is cooled and brought to the working bunker, where the lime has rs is passed through a jaw crusher and from here it falls on a vibrating sieve with Φ 40 mm mesh, of which the +40 mm class is recirculated to the jaw crusher and the -40 mm class is passed into the waiting bunker, after which takes place the elaboration of gold and silver in the electric oven

RO 128995 Β1 three-phase arc, in which the desulphurized ore is brought to the form of briquettes, so that fine fin 1 is not entrained by the gases produced in the three-phase electric arc with melting arc, the briquetting takes place using a binder and a hardener. , without the need for drying, using a 3 horizontal shaft mixer with the possibility of rotating in both directions and after charging with lighters the three-phase electric arc furnace, melt the load and obtain the alloy, 5 followed by the deoxidation of the bath, by diffusion or by precipitation, giving a reducing mixture to the bath, the mixture is slag several times, until the slag becomes white, and 7 minutes before unloading, it starts to deoxidize, through precipitation, giving into pieces the bath. of deoxidizers and the preparation is prepared in the melting pot, pot which can be 9 with a plug or drawer and which is heated to at least 1250 ° C and also s e also prepares the casting assembly, so that the normal conical ingot can be painted inside 11 with dewatered tar and preheated to at least 125 ° C; after casting the alloy, the pot stopper or drawer closes the flow hole and the slag casting pot from the 13 electric arc furnace is directed to the cylindrical mixer, where the auxiliary hook of the crane is attached to the shaft at the bottom of the pot and the slag is poured into the mixer. for storage, and after 15 the solidification of the alloy in the ingot, the striping of the ingot is performed, and after cooling the ingot, it is directed for the electrolytic refining of the gold, silver and other 17 accompanying metals, and then the electrolyte is developed in the electric arc furnace. , using fluxes such as: fluorine, quartzite, bauxite, magnesite and burnt lime, and after 19 melting of materials, samples are taken for chemical analysis of the electrolyte, after receiving the result, corrections are made, by addition of materials, and the temperature of the bath is measured. with 21 Pt-Pt immersion thermocouple 10% Rh, and electrolyte casting temperature it must be at least 6O ... 7O ° C higher than the melting temperature of the electrolyte, after which the discharge of the electrolyte is carried out in a pouring pot, which is directed to the electrolysis tank where, by tilting the casting, the electrolyte is discharged and the addition of 25 slags in the electrolyte from the electrolysis tank will be at least 5%, followed by experimentation to determine the maximum value, and then the extraction of the metal 27 from the electrolysis tank is performed using the extraction pot. with connection to the vacuum system and with inert anodes made of a weldable carbon steel block, obtained forging or molded from steel OT 29 40-1 containerized.

The installation according to the invention, as shown above, has 31 automatic dispensers with gravimetric system with weighing tape, in connection with a dispensing trolley and with a pivot which is placed on the platform of a trolley, and an oven, where the sulfur is burned. 33 of the ores, a mixer with horizontal axis for making the briquetting, and for the elaboration of gold and silver, there is provided a three-phase electric arc furnace and a casting pot 35, with stopper or drawer, and a normally tapered ingot, connected with an electrolysis tank which is equipped with a vault formed by a number of movable vault sectors 37 and independent of each other, which allow them to be lifted and rotated during the technological work in the basin, the vault sectors are constructed of refractory bricks molded 39 chromomagnetic, and on the domed sectors, there are mounted steel sheet sealing elements, welded, cooled with water circulation and electrolysis tank, using 41 precocious carbon anodes and inert anodes, in which precocious carbon anodes are encased in metal containers, comprising the lower, upper and the lateral surfaces, made of 43 refractory alloys.

The advantages of this new technology is that: 45

- does not violate the directives for environmental impact assessment, respecting

The Berlin Convention of 10 October 2001, which provides for the prohibition of the use of cyanide in 47 mining operations in the territory of the European Union and consequently does not negatively affect the

RO 128995 Β1 of soil and groundwater, as the process does not provide for the creation of a settling pond, for the storage of tailings loaded with sodium cyanide and heavy toxic metals (lead, cadmium, etc.), resulting in the technological process;

- e.g. The Roşia Montană Gold Corporation company envisages, in its project, the use of 12,0001 sodium cyanide per year, the construction of a settling pond on the Comei valley, on an area of about 300 hectares and with a dam with a height of 185 m;

- the smallest crack in the wall of this dam would destroy the city of Abrud at 2 km and of the other downstream localities;

- so serious is the fact that the bottom of the pond is located on the permeable sandstone, so it can affect not only the soil, but also the groundwater;

- Another danger is the landslide, which may have a crash;

- pursues the protection of the environment from an ecological point of view, by preventing and controlling, on the one hand, the polluting emissions, and on the other hand, it improves the working conditions, the quality of life and the working capacity of the personnel, so that the technology provided in The invention is in full compliance with the regulations of the European Environment Agency and of the Bureau of Comprehensive Pollution Prevention and Control and with those of the Vienna Convention, the Montreal Protocol, as well as the Kyoto Protocol, as the most significant documents concerning environmental and pollution;

- in other words, the technology presented in the invention is non-polluting and environmentally friendly;

- it does not involve surface excavation by stripping and therefore does not use explosions, for "stripping with serious consequences", on vibrations and seismic waves that will occur, but it involves re-opening the mines and equipping them with state-of-the-art equipment, for exploitation. to proceed in advantageous technical and economic conditions, without affecting the environment;

- it does not provide for the grinding of the relief forms, which are included in the exploitable geographical space, through works carried out in surface quarries, and as a result the characteristic landscape of the area is not destroyed, allowing the tourist potential to be used;

- it does not involve relocation and relocation measures imposed on the population in the area, with serious consequences for the Romanian state;

- it does not involve the demolition of houses, churches, cemeteries or the attainment of archaeological remains of great scientific interest and invaluable value, when all these enter into their exploitable space;

- The invention represents a feasible technical-scientific viable solution, for the recovery not only of the Roşia Montană deposit, but also of other deposits from the point of view of the chemical composition, such as: Roșia Poieni, Bucium Tarnița, Bucium Rodu, Bucium Poieni , Bucium asa, Dealul Boteș, Gura Barza etc .;

- The invention also provides for the use of the gold and silver accompanying elements, metallic and non-metallic, such as: sulfur, iron, vanadium, titanium, copper, manganese. chromium, lead, zinc, arsenic, cobalt, nickel, bismuth, tin, tellurium, molybdenum, tungsten, germanium, indium, lithium and perhaps others that will be detected by analysis, as opposed to the Roşia Montană Gold Corporation project, which is interested. only gold and silver, and the other elements pass them into the settling pond;

- The present invention is also concerned with the use of the feldspars present also in the deposit: the sodium is a raw material, for the manufacture of glass, and the potassium can be used in the ceramic industry in the manufacture of porcelain;

- how to find ores containing sulphides, and how the invention provides in the technological flow and a step of combustion of sulfur, as a result of sulfur dioxide SO ₂ , raw material for the manufacture of sulfuric acid;

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- in other words, the practical implementation of the invention causes Roșia Montană, 1 now considered a monoindustrial area, to become polyindustrial, due to the fact that, besides the productive sectors provided for in the invention, a 3 acid manufacturing plant appears necessary. sulfuric, a glass manufacturing plant and a ceramic plant, in particular, for the manufacture of porcelain. 5

The following is an example of carrying out the process according to the invention, comprising metallurgical and electrochemical phases, which refers to the electrolysis of melts, in order to obtain the hard fusible metals and the rare metals, and which is also related to FIG. 1 ... 28, which represents: 9

FIG. 1a and 1b, the technological flow and the general scheme of the installations used in the application of the proposed process;

FIG. 2, multi-storey furnace for burning sulfur from ore;

FIG. 3, a fluidized bed furnace for the burning of sulfur from the ore; 13

FIG. 4, mixer with horizontal shaft and blades;

FIG. 5, mixer with vertical shaft and blades like a concrete mixer; 15

-fig.6, the drawings of the mold for the briquetting of the ore, of the punch and of the lower and upper pellets, including the extraction pipe (when working with a single mold); 17

FIG. 7, mechanized press for ore briquetting;

FIG. 8, drawing a cylindrical lighter; 19

FIG. 9, three-phase electric arc furnace, basic lined with magnesite bricks;

FIG. 10, shapes of the arc ring of the electric arc furnace; 21

FIG. 11, the construction of the arc furnace vault;

FIG. 12, the groove is a metal cylinder, closed at the bottom with flexible metal strips 23, provided with a special fastening system;

FIG. 13, electric furnace with movable vault; 25

FIG. 14, the latch trapped in the lighter loader crane hook;

FIG. 15, casting pot with stopper, section and sketch; 27

FIG. 16, details for closing and building the molding pot;

FIG. 17, the refractory masonry for a molding pot with a drawer with a capacity of 1251; 29

FIG. 18, casting pot with drawer;

FIG. 19, ingot types; 31

FIG. 20, double casting bridge with directly conical ingots and masonry;

FIG. 21, showing the moment of casting of the alloy from the casting pot as a whole of 33 casting, through the pouring funnel, at the bottom of the inverted conical ingots, provided with masonry and of the special hook for the striped ingot;

FIG. 22, section through an electrolysis tank. The infrastructure of the vessel, the construction of the masonry and the vault, the presence of the anodes and their fixing system with anodic rod 37 of steel are observed. There is also the cathode bar made of steel and the insulating ceramic bushes;

FIG. 23, cross-section through the cylindrical mixer, observing the pouring from the 39 casting pot of the "special slags for storage and the casting pot, in front of the mixer ready to transport" the special slurry to the electrolysis tank; 41

FIG. 24, section A-A through the electrolysis tank fig. 22, representing a longitudinal section on the axis of symmetry of the vessel, in which the inclination of 2 to 8 ° in front of the horizontal 43 is observed, for the unloading of the alloy at the base of the cathode glass directly in the casting pot placed on the transport wagon; 45

FIG. 25, top view of the containerized anodes and the longitudinal section C-C through these anodes; 47

FIG. 26, variant construction of the masonry of the side walls - of the basin of fig. 22, continued with magnesite bricks, removing the printed and baked carbon mass; 49

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FIG. 27, variant construction of the masonry of the vessel of fig. 22, by plating directly on the magnesite bricks of the metal plates made of refractory alloy;

FIG. 28, construction variant of the cathodic glass of the vessel of fig. 22, wherein the cathodic carbon blocks are replaced by a molded and baked carbon mass.

In the invention, the organization of a metallurgical compound is presented, for the exploitation of the gold-silver ores.

An integrated metallurgical unit, for the use of gold and silver and other metallic and non-metallic accompanying elements, as treated in this invention, requires the following productive sectors:

- the granulometric preparation sector of the ore and other raw materials;

- the sulfur burning sector of the sulphide-containing ore;

- the sector of briquetting of the desulfurized ore;

- the gold and silver ore processing sector, in the three-phase electric arc furnace;

- the electrolyte elaboration sector in the three-phase electric arc furnace;

- the electrolysis sector of the melt, to obtain the metal accompanying elements, in addition to the deposits presented below, for ore, fluorine, quartz, bauxite, magnesite and limestone, a number of coated deposits are required, namely: the depot for deoxidants: ferrosilicon, silicocalcium, aluminum in the form of chunks, or granules, petroleum coke, graphite powder, aluminum powder, complex deoxidants, etc.

In this warehouse, there will be a mill with rings, to obtain powdery materials.

The warehouse for refractory materials such as: porous foam bricks, foam bricks, magnesite bricks, chromomagnetic bricks, ceramic fiber fabric plates and glass fiber fabric plates.

Also, there will be deposited, carbon blocks and carbon slabs, for the construction of electric ovens and electrolysis tanks, as well as carbon mass and precocious anodes.

The warehouse will store graphite electrodes and nipples for electric arc furnaces. A hall is required for the construction of the arc furnace bolts and the electrolysis tank vault.

Also in this hall, the masonry of the casting pots is executed, whether they are with a stopper or they are with a drawer, and the refractory materials are prepared, for the construction of the sulfur oxidation furnace from the sulphide ore, the electric arc furnaces, the of the mixer and the electrolysis tank.

Also, the casting assembly is prepared for casting: funnel, ingots and bottoms.

In the factory complex, apart from the productive sectors, a series of workshops are required as: mechanical, electrical and metrology, the combination will necessarily be equipped with:

- chemical analysis laboratory;

- laboratory with quantovac;

- fluorescence X-ray diffraction laboratory;

- LECO laboratory for carbon and sulfur dosing;

- laboratory with gas analyzer from solid material: oxygen, nitrogen, residual hydrogen;

- metallographic laboratory for sample preparation;

- stereomicroscope with magnifications up to x 40 for macrostructure;

- optical microscope with magnifications up to 1,500 for microstructures;

- electron microscope laboratory with magnifications up to x 80,000;

- mechanical testing laboratory;

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- laboratory for corrosion tests; 1

- electric laboratory, for measuring; intensity, voltage, power, electricity, power factor (cos cp), frequencies, resistances, conductivity, etc .; 3

- UV laboratory, for examining surface quality;

- ultrasound laboratory, for the control of forged and laminated steels, used in 5 installations with dimensions over 50 mm.

It must be emphasized to the fact that, in order to be able to work throughout the year, it is necessary 7 as in the cold period. in the productive and auxiliary sectors, ensure a temperature of at least 18 ”C, by operating the air heaters. 9

Roșia Montană is a settlement in the Land of Moților, located in the northeastern part of the Metalifera Mountains and of the gold polygon, located in a small geological basin of 11 near the cities of Abrud and Câmpeni. for years. 13

The gold-silver mineralization comes in the form of lids, vaults and impregnation areas, 15

The strands are producing native gold and less ore.

The vaults are broken columns of explosion, located on the periphery of the eruptive bodies 17 with cylindrical or striped shapes, vertical or inclined.

The impregnation zones have the gold deposited on the cracks and scattered in the mass of the rock. 19

The gold is found in native or free form in nests or veneers, as leaves or crevices, plates, octahedral crystals, grains disseminated in rock, granules associated with pyrite, blenda, 21 galena, quartz, calcite and rhodocrozite.

Also, the minerals that accompany the gold are also the minerals of silver: silver, 23 proustite, pirargerite, pearceite, polybase.

The technological flow provides the following steps: 25

- granulometric preparation of ore class -3 mm, for the combustion of sulfur and preparation of other raw materials class +10 mm;

- the presence of a furnace for burning the limestone in order to obtain the necessary lime, to obtain the electrolyte;

- combustion of sulfur from the sulphide-containing ore;

- briquetting of desulfurized ore; 31

- the elaboration of gold and silver from ore briquettes in the three-phase electric arc furnace;

- elaboration of the electrolyte in the three-phase electric arc furnace;

- electrolysis of the melt in the electrolysis tank from the slag resulted in the three-phase electric arc furnace 35, for obtaining the hard fusible metals and the rare metals.

The machines used in the invention for the mechanical preparation, mining 37 metallurgical processes and electrochemistry process within the technological flow are the following: 39

- for granulometric preparation:

- mobile grills, 41

- jaw crushers;

- vibrating screens; 43

- conical crushers;

- automatic dispensers; 45

- dispenser trolley;

- chibla; 47

- platform trolley, for placing and transporting the target;

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- for the preparation of lime:

- Limestone burning furnace;

- for the combustion of sulfur from the sulphide-containing ore:

- Herreschoff multi-type oven;

- to obtain briquettes from granulated and desulphurized ore:

- mixer;

- mechanized press;

- for the production of gold and silver from ore briquettes:

- the power supply of the three-phase electric arc furnace;

- three-phase electric arc furnace;

- casting pot;

- casting assembly;

- mixer, for storing liquid slag from the casting pot;

- for electrolyte elaboration:

- three-phase electric arc furnace;

- casting pot;

- for the electrolysis of the melt:

- casting pot;

- electrolysis tank;

- the drained pot;

- casting assembly.

We define the volumetric classification or sifting operation of the mechanical preparation, which performs the separation of a granular material into two or more classes with granular material of the same size or size.

The volumetric classification is performed dry or in the presence of water, with the help of grills and / or sieve, to dimensions between 500 and 0.02 mm.

Among the purposes of these operations is the preparation of crude or intermediate mineral substances for different concentration processes.

Another purpose is to reduce the water and fine material content of some products, so-called classification as a drying operation.

The granulometric composition is defined as the quantitative spread of the granules or of the granulometric classes, according to the average size, or the size limits in a granular mass of useful mineral substance.

The grain size composition is influenced both by the structural mechanical characteristics of the material and by the conditions under which the shredding occurred.

The particle size composition is determined using the particle size analysis.

The volumetric grading process is carried out with the help of grills and screens, whose classification surface is characterized by the size of the open spaces, so-called meshes.

We also define the useful or active classification surface the ratio between the effective area of all the meshes and the area of the entire classification surface.

If one, two or more grading surfaces with different mesh sizes are mounted on a sorting machine, more granulometric products will be obtained.

The same will be achieved when several machines are used, each having a sorting surface characterized by a certain mesh size.

In this case, the sifting can be performed with one of the following methods: by refusal, by passing, combined.

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It is specified that through the mesh of the classification surfaces can pass the granules 1 have smaller dimensions than the limit, which correspond to the size of the given eye.

As factors of influence of the process we define: internal factors, dependent on 3 physical characteristics of the material subject to classification and external factors depending on the specific of the machine and the working conditions. 5

Another important factor of the classification is the humidity of the material.

For humming it is important the external humidity, ie the water, which covers with a film the surface of the granules.

Water is found in pores and cracks, and that chemically combined does not essentially influence the grading process.

External humidity leads to the adhesion of small particles and clogging of the mesh. 11

Also, the water moistens the threads of the sieve. Under the action of surface tension forces, films are formed that sting the eyes. 13

All these prevent the stratification and implicitly the passage of the small granules through the mesh. 15

When sifting the materials with low moisture content, the granules move almost freely in the layers moving on the screen and it is possible to easily pass the 17 granules from the upper layers to the lower ones and implicitly through the mesh; is what we call dry sifting. 19

In order to improve the volumetric classification process, taking into account the adverse effect of humidity, several procedures can be used, namely: 21

- drying of the material before sifting;

- increase of the active forces of the machine to values that exceed the capillary forces of the 23 material;

- increasing the active classification surface; 25

- reducing clogging possibilities.

The classification efficiency is the better, the lower the speed of movement of the material on the screen.

Prolonged stationing of the material on the sieve negatively affects productivity. 29

For this reason, it is necessary to ensure a speed that satisfies the efficiency and productivity.31

Due to the complexity of the phenomena that occur on the screen, the speed of movement of the material on the screen is established experimentally and in most cases, by changing the angle of inclination of the frame.

The volumetric sorting machines can be classified into: 35

- bar grills: fixed and mobile;

- screenings with fixed grading surfaces: flat, curved, circular, 37

- movable flat screens: oscillating, with resonance, with linear vibration, with circular vibration, namely: rotary screens, vibrating screens, rotary screens, special construction screens. 39

By shredding is meant the operation of mechanical preparation, by which the pieces, or granules of useful mineral substances are divided into smaller ones, without changing their chemical structure or composition.

The classification implies: 43

- crushing or crushing, ie the crushing in one or more steps, in crushers, of useful mineral substances, from large to dimensions of about 1 ... 3 45 mm;

- grinding, ie the shredding of useful mineral substances, usually in mills, under 47 dimensions of about 1 ... 3 mm.

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The grinding operations have the purpose of bringing the useful mineral substances, between certain granulometric limits, also using the classification operations. Therefore, the shredding is non-existent in the preparation plants.

In the preparation processes, the crushing operations have the role of breaking down the mineralogical associations, under which the useful mineral substance is presented, releasing different mineral species in order to concentrate.

In this case, the shredding should be limited to the release of the useful minerals from the sterile ones and the useful ones from each other, in order to reduce the energy and steel consumption and to favor the technological operations of the subsequent operations.

The crushing operations can simultaneously play the role of the concentration operations, in this case, the shredding, called selective crushing, fulfills simultaneously, both the role of reducing their size and that of separating the useful waste, which can be achieved if one it is friable and the other hard, but also the other way around.

The degree of grinding is the representative feature of any grinding operation, which indicates how many times the size of the material has been reduced in the process.

The structural mechanical properties of useful mineral substances such as: elasticity, plasticity, hardness, breakage and mechanical strength, directly influence the grinding capacity, particle size and grain shape.

Therefore, the behavior of the granules, when subjected to external stresses, is dependent on their texture and cohesion forces, which keep closely together the particles that make up the crystals.

The humidity of the material influences both the mechanical strength and the shredding capacity.

The crushing makes the cutting from very large dimensions of 1000 ... 1500 mm, commonly 400 ... 200 mm, at medium and small dimensions, ie 3 ... 5 mm.

The crushing is done in crushers, which can be classified into: crushers and granulators with jaws, rotary and conical crushers, roller crushers, hammer crushers and impact crushers.

Crushers with jaws are used for crushing hard and very useful mineral substances, and sometimes those with medium or even low hardness.

Granulators with jaws are used for the intermediate and even small crushing of useful mineral substances hard or medium hard.

The rotary crushers are used for primary and conical crushing, for intermediate and small crushing of useful hard and medium hard mineral substances.

The roller crushers are used for intermediate and small crushing, but also for primary crushing of medium hardness and soft clay minerals.

Considering the mode of action on the material to be crushed, the crushers are constructed with the surface of the smooth, grooved, or toothed rollers.

Those with a smooth or grooved surface are used for intermediate and small crushing of useful mineral substances of any hardness, except for very hard ones, acting by compression, friction and shearing.

The main action of breaking the rollers with toothed surface is the shearing, used for the shredding of friable, soft and clay mineral substances.

Crushers with hammers and impact crushers crush the fragile, soft and medium-hard mineral substances on the base of the shock effect, being used for primary, intermediate and small crushes.

In hammer crushers, the shredding is mainly due to the material being hit by the hammers and only secondary to its collision with the plate or shield bars, while at those with impact, the phenomena are carried out in reverse order.

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Disintegrators are used, for the fine crushing of useful mineral substances1, for soft and friable materials, or for the homogenization of melting mixtures in metallurgy.3

The crushing operations are accompanied by volumetric classification operations, with which they work in the open or closed circuit.5

The crushing operation, together with the corresponding grading operation, forms a crushing step.7

The totality of the steps constitutes the crushing scheme.

The gold-silver ore, from a granulometric point of view, is subjected to 9 crushing, grinding and grading operations, in order to be suitable for different purposes.

Thus, the crude ore extracted from the mine is subjected to crushing, grinding and grading up to 11 in class-3 mm, and the other raw materials of the electrolyte are subjected to the same operations up to class +10 mm, and lime up to class -40 mm. 13

According to the invention, in table 1, the chemical compositions of the ore from the Roşia Montană deposit are presented, as far as could be obtained by the author of this work and the 15 obligatory ones of: fluorine, quartzite, bauxite, magnesite, limestone, burnt lime, ferrosilica , silicon, aluminum, petroleum coke, graphite powders, 17 aluminum powders.

Within the invention, it is presented the organization of the preparation of materials, by homogenization, 19 crushing and sorting by dimensions, which determines the technological process at optimal parameters, both from the point of view of the specific consumption of materials and 21 of the energy consumption.

Raw materials and auxiliary materials are transported by means of transport such as: 23 in railway wagons or by car and are unloaded at a unloading station.

The ore displaced from the deposit to the working front is transported from the abattoir with the help of the wagons from the inside to the surface, through the main well with the extraction cage and then directed to the unloading station. 27

If the composition of the ore varies to a large extent, it is necessary to homogenise it from a compositional point of view, in a special station, after which it is transported 29 on a conveyor belt in railway wagons.

The railway is thus built on a railing, in which a part of the railway is located above the warehouses, where with the aid of the wagon-ends, the ore, as well as the other raw materials are unloaded in the respective warehouses. 33

Deposits have the role of storing ore and raw materials, ensuring the operation of the plant complex, for a well-determined period of time.35

The diagram of the technological flow of the recovery process of the Roşia Montană deposit, as well as of other similar deposits, according to the invention, is presented in fig. 1a and 1b, 37 with the necessary explanations in the accompanying legend.

Thus, the deposits noted in fig. 1a with A-A comprise: ore 1, fluorine 2, quartzite 3.39 bauxite 4 and magnesite 5.

In general, the transportation from warehouses to work bunkers, noted in fig. 1a with B-B 41 is made with conveyor belts.

B-B working bunkers include: ore 6 and fluxes: fluorine 7, quartzite 8, bauxite 43 9 and magnesite 10.

From the work bunkers, the materials are brought and subjected to preparatory operations, 45 which consist of:

- sorting on grills, 47

- crushing,

- and sorting by grain size on vibrating screens. 49

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From the B-B working bunkers, the materials, with the exception of fluorine, are passed over the gratings marked with 11, 12, 13 and 14, which have Φ 80 mm mesh.

From these grates, the +80 mm class, like fluorine in work bunker 7, pass into jaw crushers with 15, 16, 17, 18 and 19 jaws.

The -80 mm grade on the grill passes through the vibrating screens rated 20, 21, 22, 23 and

24, as the class-40 mm, which results from jaw crushers with 15,16,17,18 and 19

The +40 mm class is recycled to the jaw crushers 15, 16, 17.18 and 19.

The -40 mm class from the vibrating screens rated 20, 21, 22, 23 and 24 passes into 9 conical crushers marked with 25, 26, 27, 28 and 29 and then on the vibrating screens with 31, 32, 33 and 34 with mesh Φ 10 mm.

The +10 mm class is passed in the C-C waiting bunkers with 36.37, 38 and 39.

Class -10 mm is directed to a pelletizing plant, to be used for 13 other purposes, depending on their granulations, problems known and applied in industrial practice.

The ore from the conical crusher 25 passes through the vibrating sieve 30 with de 15 3 mm mesh.

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RO 128995 Β1

The +3 mm class is recycled to the conical crusher 25 and the -3 mm class passes into the waiting hopper 35.

The materials in the waiting bunkers pass into the automatic dispensers, scored with 47.48, 49, 50 and 51 with gravimetric system with weighing tape.

Thus, from the automatic dispenser 47, the ore is passed to the dispenser trolley 52, from which it is discharged into the chute 53.

Chibla 53 is placed on the platform of a trolley 54 and is guided under the hook of the crane 55, which supports the yoke with the two hooks. The chibla is raised by the hooks of the yoke and is directed to the bunker 56 of granulated ore feed of the furnace E, for the burning of sulfur from the sulphide ore.

From the limestone deposit 40, the limestone with a granulation between Φ 60 and Φ 80 mm is brought to the combustion furnace of limestone D on the conveyor belt, where by means of a skip 41 it is loaded into the upper part of the furnace 42.

The furnace is heated with methane gas, reaching a temperature of 1250 “C in the area of the burners, so that, when the limestone is lowered in the furnace, it is dissociated, the burnt lime is obtained, a known process is applied.

The burned lime is cooled and brought with chibble to the working bunker 43 of the B-B complex.

From the working hopper 43, the burned lime is passed through a jaw crusher 44, and from here it falls on a vibrating sieve 45 with Φ 40 mm mesh, of which the +40 mm class is recycled to the jaw crusher 44, and the class -40 mm is passed into the waiting hopper 46 and from the hopper into the automatic dispenser 58.

In extractive metallurgy, obtaining metals from sulfur-containing ores, so-called sulfurous ores, is not possible without a sulfur burning in the presence of oxygen in the air.

Within the technological flow this operation of combustion of sulfur is foreseen, during the heating process, in the first stage, evaporation of moisture from the ore takes place.

The water will not be completely eliminated at 100 ° C, because its vapor pressure is lower in the adsorbed state, and as a result the elimination of the last quantities of water always overlaps with the dissociation of hydroxides, which takes place up to 550 ° C.

It should be noted that the process of combustion of sulfur represents an exothermic reaction, that is, once it has been primed, it proceeds by itself, according to the reaction (1).

2MeS + 3O ₂ - 2MeO + 2SO ₂ (ΔΗ <0) (1)

Therefore, sulfur from sulfur ore is a fuel, because it releases a lot of heat, so that at a certain temperature, the process of combustion of sulfur becomes energetic, due to the fact that, when heating sulfur in the air, at a certain time , the combustion reaction accelerates and the process speed increases.

Under these conditions, the heat released is sufficient to cover the heat required for exothermic reactions, radiation losses, heating of the surrounding air and raising the temperature of the sulphides.

As a result of the combustion process, SO ₂ sulfur dioxide is produced, which is discharged.

By decreasing the reaction rate, as a result of the sulfur burning, the amount of heat, which is released, decreases in the unit of time, and at one point, it becomes equal to the heat loss and at this moment the sulfur burning ceases and a additional heat, by operating burners with liquid hydrocarbons or gases, so that the process can continue.

RO 128995 Β1

The combustion of sulfur from sulfides, as well as the dissociation of sulfates and carbonates, occurs in 1 temperature range 200 ... 700 ° C.

At temperatures above 700 ° C, metal oxides begin to form.3

Considering that the melting temperature of Ag ₂ S silver sulphide is 842 ° C, it has been established in the invention that the sulfur burning temperature is between 750 and 800 ° C.5

The period of time required for the total removal of sulfur from a sulphide grain is based on the grain size and the longer it is, the larger the size7. In the present invention, the ore prepared for desulphurisation has a granulation of less than 3 mm. Also, this period is also dependent on the combustion temperature 9 of the sulfur in sulfur, which is dependent on the nature of the sulfur, thereby understanding the temperature at which the combustion process is carried out independently, without the addition of heat 11 from the outside.

Knowing this temperature allows to determine the optimum conditions for the combustion process 13.

Another important factor to take into account is that during the combustion process 15, the temperature does not rise too high, so that the agglomeration of ore granules does not occur, which would contribute to the diffusion of oxygen diffusion to the area. of 17 reaction, and as a result would decrease the firing rate.

Analyzing reaction (1) this is more energetic, the higher the temperature and the air circulation in the furnace is more intense.

The temperature achieved during the combustion process depends on the sulfur content 21 of the ore, the amount of air entering the furnace, the amount of ore charged in the unit of time. 2. 3

Each sulfur sulfur burning process is characterized by a certain value of the degree of combustion, that is, the amount of sulfur expressed in%, remaining in the ore at the end of the process and by a certain degree of desulfurization η, being understood by this is the ratio between the quantity of sulfur burned during the process and the initial quantity of sulfur 27 contained in the ore, according to equation (2).

η = 100 (1-qSySj) (2) 29 where:

Sj = the sulfur content of the ore loaded in the furnace, expressed as%; 31

S ₂ = sulfur content of desulphurized ore in%;

q = burnt ore, result (between 0.8 and 0.9) of the total weight of the ore.33

When oxidizing some sulphides, pure metals can be obtained, but this is only when the oxides of these metals are not stable at high temperatures, such as the sulphides of the noble gold and 35 silver metals, expressed in reactions (3) and (4):

Au ₂ S + O ₂ = 2 Au + SO ₂ (3) 37

Ag ₂ S + O ₂ = 2Ag + SO ₂ (4)

The combustion of sulfur from the sulphide-containing ore is performed according to several processes, 39 in furnaces, two of which are known and applied in the present invention.

a. The combustion of sulfur is carried out in multi-storey ovens, Herreshoff, with six to 41 twelve floors. in FIG. 2, the diagram of the multi-stage sulfur combustion furnace from the sulphide ore is presented. 43

The furnace has a central axis 1, made of refractory steel, from which some mechanical arms 2 are made, made of cast iron, so that on each floor and each arm, it has 45 combs 3, of helical form, which mixes the ore granules and them distributes throughout the floor area. 47

RO 128995 Β1

Each floor communicates with the others, through openings specifically practiced 4. Above the oven is mounted a hopper 5, in which the ore with sulfur content is prepared, prepared to the required granulation, less than 3 mm. The ore is further conveyed by a helical conveyor driven by a motor with gearbox 6, and enters the top of the furnace through an inclined tube 7.

The central axis is supported on roller bearings and rotated by a gear motor.

Both the central shaft and the mechanical arms are cooled by a cool air stream provided by a fan 8.

The granulated ore passes successively through all the floors, after which the granules are taken over by the last arm whose spins direct the ore into the unloading funnel 9 and from here into wagon 10. At the top of the furnace, sufficient heat is released from the exothermic reaction, in this way that the upper floors do not need to be heated. In the lower part of the oven, due to the decrease of the sulfur content, even below 1%, the reaction having too little heat, it is necessary that the penultimate two floors of the oven be heated with the burners 11, which use liquid fuel or methane gas.

On the lower floor, the cooled desulfurized material is collected, as it was dragged upwards, in wagon 10, and is transported, for the briquetting operation.

The temperature regulation on each floor is realized automatically, by modifying the flow of blown air.

The temperature is controlled by means of thermocouples 12, mounted on each floor. The gases produced on each floor are sent to dry treatment, after which the sulfur dioxide SO ₂ is used in the manufacture of sulfuric acid H ₂ SO ₄ .

b. In the method of combustion of the sulfur in a fluidized layer, from the sulphide-containing ore, the solid sulfides in the form of granules are treated in a reactor with a moving fluid. The sulfur in the sulphides is oxidized by a rising air stream, which crosses from the bottom up the moving mass of the ore, printing its turbulence like a boiling liquid.

During the combustion of the sulfur in a fluidized layer, the oxidation process proceeds at a maximum speed, because favorable conditions are created, for the diffusion of oxygen in the reaction zone and for the elimination of SO ₂ through the film of solid oxidation products.

The oxidation of the sulfur in a fluidized layer is carried out at the speeds of the oxidizing agent between the minimum speed of fluidization and the driving speed.

The heating of the ore can be achieved only by convection by the oxidizing agent, or by convection and conduction, the support being heated, possibly being able to be associated with the radiation from the refractory lining of the furnace.

The mass of solids and gas, which reacts, is found at practically the same temperature and each grain of material during the process is in the stream of hot gases containing oxygen.

The fluidized layer oxidation process has some advantages over other processes, among which we mention:

- an increase of the reaction rate due to the contact between the two phases, which leads to a higher quality of the oxidized ore;

- heat transfer with the possibility of regulating and maintaining the temperature in the fluidized ore layer.

RO 128995 Bl

The fluidized bed installation, shown in fig. 3, is composed of a metallic shell of 1 cylindrical or conical shape 1. lined inside with refractory material, a ore feed hopper 2, a metering device 3, feed tube 4, sieve or plate 3 perforated to maintain the fluidized layer 5, which has the role and uniform distribution of the oxidizing agent, ie air carried by a fan 11, which is also preheated, the fluidized layer 5 6, burner for priming 7, the exhaust pipe of the burnt ore 8, the upper chamber of the furnace 9, the drainage pipe for sulfur dioxide 10, cyclone 12, wagon for 7 transport of burnt ore 13 to the briquetting operation.

The granulated and oxidized ore, regardless of which furnace E is obtained, is taken by 9 a wagon 57, which transports them, for the briquetting operation, in the respective sector.

With the help of the auxiliary hook of the crane which is caught in the wagon shaft, and with the two 11 hooks of the yoke, which catch the lateral axles of the wagon, the wagon is overturned in the hopper 59, where the ore briquetting sector is fed. 13

As has been shown, sulfur dioxide SO ₂ is obtained by combustion of sulfur, but some by-products are also produced, which are driven by gas in the form of fine particles of desulfurized ore or as vapors of metals or metalloids or oxides. with low volatility temperature I iza re. 17

The sedimentation separation of suspended particles from a gas occurs in deposition or dust chambers.19

Dust chambers are parallelepiped rooms, which the gas travels at low speeds and contain significant amounts of dust.21

For sedimentation to proceed normally, the inlet velocity must be uniformly distributed across the width of the chamber.23

The gas velocity must be between 0.15 and 0.30 m / s, which leads to the separation of particles with a diameter of over 200 microns, to a purification degree of 60 ... 70% .25

From the dust chamber, the gas enters the so-called dust cyclone, representing a static apparatus, characterized by increasing sedimentation forces up to 27 to 2500 times over gravitational forces.

Experimentally it has been shown that the efficiency of a cyclone is higher, the smaller its diameter is. From this point of view, the idea of building cyclone batteries with a diameter of 150 to 200 mm appeared. 31

The phenomenon of cyclone separation is conditioned by the ratio between the centrifugal force F _a and the forward resistance force R _s . 33

The gas stream enters tangentially and rotates.

Therefore, a pneumatic binder, ie a pneumatic dust separator 35 (dust cleaner), is used for advanced gas purification, based on the principles of the flow of two-phase fluids in storage spaces, both gravitational and centrifugal. 37

In order to obtain the highest purity of sulfur dioxide, the invention recommends, in addition to the use of a dust cyclone, and the use of filter bags, 39 made of silicone and graphite glass fibers.

The gas purification plant enters the group of devices in dry environment, since 41 in humid environment would produce sulfuric acid SO ₄ H ₂ .

In Table 2, are presented, in ascending order of atomic number, the metals and 43 accompanying metalloids, existing in the ores from the Roşia Montană deposit, together with some of their physical properties (density expressed in g.cnr ³ , melting temperature 45 and boiling point expressed in ° C).

RO 128995 Β1

It is noted that some of the metal and non-metallic elements in the table have melting and volatilization temperatures in the field of sulfur burning temperatures, and as a result, by cooling, they will be in the form of fine particles.

According to a graph, at a certain time, the installation and cooling of the installation, the cleaning of the windows of the multi-storey oven, the pipe, the dust chamber and the cyclone take place.

Removing dust from the dry treatment plant will be done with care, using sealed systems, on the one hand, so as not to contaminate the environment in the workroom, and on the other hand, so as not to lose the elements or compounds such as: arsenic , selenium, cadmium, molybdenum trioxide and others, which will be determined by analysis.

The magnifiers on the windows of the multi-storey oven and the powders will be sent to the recovery plant of the existing elements and detected based on analyzes.

For the stage provided in the technological flow, represented by the melting of the desulfurized ore in the three-phase electric arc furnace, it is necessary that the ore granules be brought to the form of briquettes, so that the fine grit is not entrained by the gases produced during the melting in three-phase electric arc furnace.

In the invention, a solution for making briquettes is presented.

The briquetting is the process of transforming a material of the ground or powdered state into a product in the form of pieces in certain geometric shapes of identical size and weight by pressing in a mold. From a physical point of view, the lighters must meet a number of conditions such as:

- resistance in variable atmospheric conditions, in the sense of not deteriorating under the influence of temperature and humidity variations in the working atmosphere;

- crushing resistance;

- humidity as low as 0.01%;

- density as close as possible to the density of the non-coarse material.

Generally, depending on the initial characteristics of the material subjected to the briquetting, the pressing can be done with or without additions of binders, at variable values of the specific pressure, with or without subsequent treatment.

depending on the granulation and the chemical-mineralogical properties of the material, the briquetting will be done at high pressures, in the absence of the binders in the material.

The natural or synthetic materials, which mixed with the briquetting material lead to more or less plastic masses, masses which, under certain conditions, become resistant to mechanical, static or dynamic demands, are called binders.

Table 2

Nr. crt. Nr. atomic Name Density in g / cm ³ The temperatures in ^e C melting boiling 1. 3 lithium .5340 180.54 1342 2. 22 Titanium 4.5060 1668 3287 3. 2. 3 vanadium 6.0000 1910 3407 4. 24 Chromium 7.1900 1907 2671 5. 25 Manganese 7.2100 1246 2061 6. 26 Fer 7.8740 1538 2862 7. 27 Cobalt 8.9000 1495 2927 8. 28 Nickel 8.4080 1455 2913

RO 128995 Bl

Table 2 (continued) 1

Nr. crt. Nr. atomic Name Density in g / cm ³ Temperatures in ° C melting boiling 9. 29 Copper 8.9400 1084.62 2562 10. 30 Zinc - 7.1400 419.53 907 11. 31 Somebody 5.9100 29.76 2204 12. 32 German someone 5.3230 938.25 2833 13. 33 arsenic 5.7270 817 614 14. 34 Selenium 4.7900 221 684.6 15. 42 molybdenum 10.2800 2623 4639 16. 47 Silver 10.4900 961.78 2162 17. 48 Cadmium 8.6500 321.07 767 18. 49 indium 7.3100 156.59 2072 19. 50 Stan some 7.3600 231.93 2602 20. 52 tellurium 6.2400 449.51 988 21. 74 Wolfram 19.2500 3422 5555 22. 79 Gold 19.3000 1064.18 2856 2. 3. 82: Lead 11.3400 327.46 1749 24. 83 Bismuth 9.7800 271.5 1584

The binders confer mechanical resistance to the material subjected to the raw or briquetting 21 as a result of chemical (oxidation and polymerization) or physical hardening (pressing, melting) processes. 2. 3

Depending on their origin, binders can be natural or synthetic.

The binders can be grouped into: natural and synthetic inorganics, synthetic organics. 25

Of the natural inorganic binders, the most important are clays and bentonites.

In the group of synthetic inorganic binders mineral binders enter, which undergo a more or less complex processing process, have special properties of binders and have constant properties. 29 in this group, include sodium silicate, cement and lime.

Synthetic organic binders include synthetic resins, dextrin, molasses, sulphite lye 31, tar etc.

Of these, synthetic resins are used mostly in the manufacture of shapes and 33 cores in steel, cast iron or non-ferrous foundries.

Synthetic organic binders burn at higher temperatures, about 400 ° C. 35

Synthetic organic binders, in terms of their affinity to water, can be hydrophilic such as: dextrin, molasses, sulphite lye, or hydrophobic such as: pitcher, rosin etc. 37

The choice of the binder as a solution for obtaining briquettes from the ore -3 mm class aimed not to influence the quality of the ore and to fulfill its role in the process of making gold and silver.

The mixing of the oxidized ore (class -3 mm) with the binder is carried out in a 41 mixer with a horizontal axis and with blades of a certain geometry, to allow mixing both horizontally and vertically. 43

RO 128995 Β1 in fig. 4 shows a longitudinal section through a horizontal Cuax mixer, in which the geometry of the pallets and their attachment mode are shown.

Also, the mixing can be done also in a mixer with vertical axis and pallets, like a concrete mixer shown in fig. 5.

The mixer with horizontal axis as well as the one with vertical axis must be provided with the possibility of rotating the axis in both directions. In addition, the one with the vertical axis must have the possibility of tilting, to evacuate the mixture, and the one with the horizontal axis must have the possibility of evacuation through a central opening or through lateral openings at the ends of the mixer, by the rotational movement of the straws.

For pressing the resulting mixture, a die made from the steel mark C 120 is used, with a hardness between 60 and 62 HRC.

The drawing of the mold, the punch and the lower and upper pills are shown in fig. 6, in which: 1 - punch, 2 - mold, 3 - upper pill, 4 - lower pill, 5 extraction pipe (only when working with a single mold).

For the extraction of the cylindrical lighter, in the case of a non-mechanized press, use a pipe of the steel mark OLT 35, also shown in fig. 5.

The pressing is performed with a universal mechanical test machine ZD 40, in which the mechanical characteristics are the following:

- maximum force 400 kN;

- distance between traction bins: 25 ... 750 mm;

- the distance between compression plates: 300 mm;

- travel speed 300 ± 30 mm / min.

For the organization of continuous flow production, as provided in the invention, a mechanized press F. is used.

The machined press is provided with a carousel type table, on which the molds are placed in order to obtain the briquettes in cylindrical, cubic, or in any other form.

As a binder, for making briquettes, the FR 3 turanine resin was chosen, obtained by condensing urea with formaldehyde and furfuryl alcohol with a density at 20 ° C of 1,785 g.cnr ³ and viscosity at 20'C of 26 mPas (cP).

As a reinforcer, for the turanine resin FR 3 is SBM - 20 with density at 20 ° C 1,175 g.cnr ³ .

In the mixer insert, while the bladed shaft rotates, the granulated ore and the benzene sulfbnrc acid hardener type SBM-20 and after a minute of mixing, add the turanine resin type FR 3, the mixing continuing for another 2 minutes, after which the mixture is spilled onto a conveyor belt, which takes it to the bunker of the press machine.

It should be mentioned that, in this process, with cold self-curing and at which drying is not necessary, for the ambient temperature, which is between 20 and 25 ° C, the experiments showed that the hardener should be added in proportion of 29 ... 32% takes the amount of turanine resin, and the turanine resin is added in a proportion of 2.2 ... 2.4% to the quantity of granulated ore.

From the bunker, the desulfurized mixture is discharged into wagon 60, which is directed to the briquetting press.

in FIG. 7 shows the mechanized carousel type press, in which: 1 - press body, 2 - carousel type table with a certain number of workstations, 3 - ejector lighter molding mechanism, 4 - carousel table indexing mechanism, 5 - ore briquetting mold, 6 - feeder-dispenser, 7 - lighter or sloping lighter removal device, 8 - hydraulic cylinder, 9 - mixing press piston in the mold, and 10 - pressed lighter.

RO 128995 Bl in this case, it is a single-axis single-acting pressing, in which the die 1 is fixed, the upper punch presses, and the lower one ejects. The briquettes obtained are loaded in wagon 61 and transported to warehouse N for their storage. 3 in Fig. 8 shows the drawing of a cylindrical lighter.

The test of the compressive strength of the briquettes is performed on the same universal machine 5 mentioned above.

The operation of the three-phase electric arc furnace is based on the use of heat 7 of the electric arc.

The Heroult type furnace with non-conducting electric fireplace has the following 9 qualities:

- constitutes a robust, simple, precise operating complex, with profile, which ensures 11 servicing, driving and easy maintenance;

- each electrode is in the phase circuit and each phase works independently. 13

The electric current passes from the electrode, through the electric arc to the molten bath, which it crosses and thus the circuit closes; 15

- it provides a simple way of producing heat above the bath, because in the electric arc a temperature of over 3300 ° C is achieved, allowing the temperature and atmosphere of the oven to be controlled, whether it be oxidizing, neutral, or reducing;

- allowed the scientific basis of the processes, ensuring the understanding of the influence of 19 high temperatures on the refining and deoxidation.

The electric oven consists of a metal construction, a refractory masonry and 21 electrical installations.

The metal construction comprises: the metal tank with its attachments, the ring of the vault, the tilting device 23 and the construction, for gripping-holding and the handling of the electrodes.

As annexes to the basin, they are: the outlet with the outlet trough, the loading door and the 25-bolt ring, which supports the masonry of the vault.

In the case of furnaces, which are loaded on the top, moreover, the most widespread version, 27 the lifting and turning of the vault is carried out together with the supports of the electrodes by means of a hydraulic installation whose foundation is independent of that of the furnace. 29

Electricity from the high voltage network of 110 or 220 kV enters the furnace network through a transformer station of 15000 ... 30000 V.31

The electric current enters the oven network through a separator, which closes and opens only with the high voltage switch. the switch is pneumatic.33

After the switch, the high voltage electrical current passes to the transformer of the furnace, before which a shock coil is interposed.35

On each phase, both on the high voltage circuit and on the low voltage circuit of the furnace, voltage and intensity transformers are provided, which 37 supply the measuring devices such as: voltmeters, ammeter, wattmeters, meter, safety devices , ie the maximum current and the minimum voltage relay and the devices, 39 which regulate the positions of the electrodes and the power taken from the transformer.

The invention deals with the elaboration of gold and silver in three-phase electric arc furnace, in 41 which the lining of the arc furnace is presented in 4 variants.

Variant 1 43

The lining of the electric arc with a basic arc with magnesite bricks.

Glass masonry 45

On the metallic mantle of the bottom of the oven, the insulation with ceramic fiber fabric plates is executed, on which is placed a layer of chamomile powder and a row of 47 porous chambers bricks on the side, built with refractory cement.

RO 128995 Β1

The drying of the masonry is carried out and then it is continued with a layer of magnesite granules, mixed with dehydrated tar, after which, depending on the capacity of the oven, two to four rows of magnesite bricks are built on one side, and one to two rows on the other. edge. The bricks are built without mortar with joints, which are filled with magnesite powder heated to 70 ... 100 ° C.

Drying and cleaning is performed, and the magnesite masonry is sprayed with dehydrated tar, followed by a monolithic wear of magnesite granules, with the granulation Between 2 and 5 mm and 25% below 1 mm and 7 ... 12% tar dehydrated, mixed at a temperature between 80 and 1OO ° C.

The monolithic mixing is done at a temperature over 60 ° C, with pneumatic hammers in layers of 50 ... 70 mm, up to a thickness of 200 ... 400 mm, depending on the capacity of the oven.

The outlet is built with 2-3 superimposed bolts, made of chromomagnetic bricks (66% MgO and 10% Cr ₂ O ₃ ).

The drain trough is built with magnesite bricks with joints below 1 mm, fig. 9.

Masonry of walls.

The cylindrical sheath is insulated with ceramic fiber fabric plates and a row of wide-brimmed bricks, after which the construction is continued with magnesite bricks, and in the joints sprinkle of magnesite dust.

The door bolts are also made with chromomagnetic bricks shaped fig. 9. Masonry of the vault.

The vault is the most requested thermal and mechanical construction element, taking into account the tensions that arise due to the expansion and the heavy weight of the masonry. The masonry of the vault is executed on a template, having the profile of the vault inside the oven. The vault ring is placed on the template, and next to the electrode holes, 3 cylindrical pieces of wood or steel are mounted, having a slightly larger diameter than the electrodes.

The masonry begins with the support bricks, fig. 10, placed tightly on the ring of the vault.

The vault ring is a metal ring of various shapes and in FIG. 10 the following solutions are presented:

- U steel,

- welded tape and corners;

- with steel pipe with cooling water circulation;

- cast steel with inclined wall, to allow free expansion of the masonry;

- with sloping board and water cooling;

- with welded board on the outside (and therefore without danger of water leaking into the furnace);

- with cooling pipe welded to the soles of the ring and with sand seal;

- with 3 or 4 segments of circular support supported, by strong spring bolts, which take over the dilations and contractions.

The building of the vault is continued towards the center with small joints in concentric circles with shaped bricks, fig. 11, making the following arrangements of bricks:

- in concentric circles with higher shaped bricks in the area of the electrode holes, holes even in the bricks, fig. 11;

- with radial wedge bricks, fig. T1b;

- in concentric circles with radial wedge bricks as well as the electrode holes fig. 11c;

- in concentric circles of the whole central area, fig. 11 d;

- in straight rows with normal wedge bricks and radial wedge bricks at the holes, for electrodes, fig, 1 le and f.

RO 128995 Bl

The vault is made of chromomagnetic bricks built with magnesite mortar or 1 with thin sheet, respectively, wire or mortar fabric, making a good welding of bricks in monolith. 3

In order to prevent the hot gases coming out of the furnace near the electrodes, when they exit the vault, around which the bricks have to form a flat surface, sealing rings made of sheet and welded, using the finely processed surface and the slightly larger diameter, are used. than the electrode, so that its movement is not switched off. The sealing rings are cooled with water circulation.

The commissioning of the electric arc furnace requires some mandatory measures. 9

The durability of the masonry also depends on how dry it is, to remove moisture, it is heated. 11

Due to the fact that the humidity was not completely removed, in a large factory in the country, at the first load of steel melting, there was an explosion with serious consequences, for the 13 service personnel of the furnace.

After finishing the walls in the basic furnace, a sealing layer 15 of magnesite dust is sprinkled on top, after which the vault and electrodes are perfectly centered and dried. 17

It starts with wood fire for 4 hours, after which the drying is continued with coke and blown air for 4 hours, after previously the fireplace was cleaned of the ash resulting from 19 wood burning.

At the end of the drying process, the hearth is cleaned and the oven is filled with coke until level 21 slag.

Lower the electrodes to the top of the coke and start heating with electric current 23, with the transformer connected to the star with the voltage at 120 V and the intensity at 700 A per phase. The current is interrupted at intervals of 20 minutes for 30 minutes at first, then 25 times shorter intervals, so that the masonry temperature increases by 40 ° C / h, until the masonry has reached 400 ° C, when it increases the current intensity to about 2000 A, so that the 27 masonry temperature increases by 130 ° C / hour to 1350C, maintaining red until the volatile matter is completely removed from the tar. Above 1350 ° C, up to the annealing temperature 29 of the wear monolith, the electric current is used at the same intensity, but with the voltage of 220 V, and the transformer connected in triangle. 31

After the hot operations are completed, no more than 48 hours, remove the coke from the oven and clean the ash from the hearth. 33

The first batch of steel with low load is elaborated and the period after melting is shortened, in other words a steel with light prescriptions is developed. 35

Variant 2

Also, the drying and heating are performed as in variant 1. The lining 37 of the electric arc furnace is made by stamping, with refractory granulated material. The material has a granulation range between 0.06 and 6 mm. From the point of view of the 39 chemical composition, the granulated material has: MgO 71%; Fe ₂ O ₃ 4.6%; AI ₂ O ₃ + Mn ₃ O ₄ 1.1%; CaO 22% and SiO ₂ 0.6%. 41

It is stamped with a pneumatic hammer and has a limit of use of 175Q ° C. 43

The insulation on the metal casing is the same as in version 1. Also, the drying and heating are performed as in version 1. 45

RO 128995 Β1

Variant 3

Coating the electric arc furnace with carbon blocks. The carbon blocks must correspond to the following physical characteristics:

- apparent density 1.49 kg / dm ³ ;

- minimum density 1.80 kg / dm ³ ;

- maximum porosity of maximum 20%;

- minimum compressive strength 27 N / mm ² .

The carbon blocks belong to the category of resistive materials and, therefore, they conduct the electric current, which necessarily imposes the electrical isolation from the metal sheath of the furnace, introducing between them an electrical insulating material, that is to say plates of fabric. fiber glass.

The processing of carbon blocks is performed with diamond disks.

When building the electric oven with carbon blocks, between the joints a raw carbon mass is introduced, when with the heating of the oven the process of coking at a temperature of 1150 ± 10 ° C is also carried out.

Variant 4

The lining of the electric oven with carbon mass.

It is specified that the carbon mass is used:

- for ovens with continuous operation, for self-sealing electrodes;

- as a paste for baking vats;

- for filling the joints between the cathodic carbon blocks and for fixing the carbon slabs, which are lined with electrolysis sails;

- as a paste for precooked anodes, from electrolysis tanks, for example, in the case of aluminum production.

The carbon mass in the raw state is in the form of parallelepipedal calipers with dimensions of 435 x 140 x 165 mm, the smooth and broken surface has a glossy surface.

At ambient temperature it is in a solid state and begins to soften at about 45 ° C.

The baked carbon mass has a density density of 1.90 x 103 kg / m ³ and a compressive strength of 9.81 N / mm ² .

The storage is done in specially arranged places, in order to be protected from moisture and from purification with dust, sand, charging materials, etc.

Because the carbon mass is also part of the resistive materials category and therefore it conducts the electric current, it is compulsory to electrically insulate it from the metal sheath of the oven, inserting plates of fiberglass fabric, that is to say a material with electro-insulating characteristics corresponding to a piercing voltage of 5 kV.

The coking of the crude carbon mass is completed at a temperature of 1150 ± 1 ° C, and the heating is done according to a diagram in a determined and rigorously respected thermal regime in two stages.

In the first step, the heating lasts for 23 hours, until the temperature reaches 510 ° C, the temperature at which an hour is made. During this time, the temperature of the carbon mass is measured with a chromel-aluminum contact thermocouple.

The second step is performed for 9 hours, until the temperature reaches 1150 ± 10 ° C, when the baking process is completed.

It is mentioned that the vault of the electric arc furnace, for variants 2,3 and 4, is the same as in variant 1, and also as the drying and heating operations.

RO 128995 Β1 charging the oven. 1 The charging of the electric arc furnace is made with ore briquettes prepared for this purpose and which are inserted in the trailer. 3

The beam is a metal cylinder closed at the bottom with flexible metal bands, provided with a special clamping system. The most used system is the connection of the ends of the 5 bands with a rope soaked in the tar, which burns when inserted in the oven and the basket of the bin opens, fig. 7 in FIG. 12a, the bottom of the basket with flexible strips is shown, and in FIG. 12b, the basket is presented. 9

The method of loading the kiln with the tiller involves, first of all, the lifting and removal of the pivoting bolt, after which the load caught in the crane hook is brought 11 above the oven, approaching the hearth, fig. 13.

Lifting the bin, the locking system is detached, as shown before and 13 the load of lighters falls from a low height on the hearth, after which the crane with the bin returns to the warehouse N, storing briquettes. 15

The vault is restored to the furnace like the graphite electrodes, which are lowered until close to the load. 17

After charging, if necessary, correct the lighters' positioning with the hook and connect the oven to the mains with the help of the high voltage switch, 19 for the large capacity ovens, and for the medium and small ovens with the shock coil in the circuit. 21

elaboration

To ensure a stable arc it is thrown under the coke electrodes. This measure 23 prevents sudden fluctuations of intensity.

If the charge from the beginning provides a stable electric arc, the melting is carried out with 25 automatic voltage regulating system in the medium voltage circuit.

Continue, gradually increasing the power up to 2/3 of the rated power of the 27 transformer.

The duration of the melting decreases with the increase of the power of the transformer, as the electrical efficiency is improved.

It is necessary to conduct the thermal regime correctly, that is to say the relations 31 between the electric charge, voltage, intensity, cos (φ), taking into account the heat absorption capacity of the loads and the thermal possibilities of the refractory materials. 33

Additions of fluxes, if necessary, are made to obtain a fluid and active slag. These fluxes are: fluorine, bauxite, etc.35

When all the load has melted, the furnace is disconnected from the electrical grid and the coke is removed from the surface of the bath using the wooden dowel.37

The period of deoxidation of the bath is the last stage in obtaining gold and silver.

At this stage of elaboration, the following problems must be solved: 39

- to deoxidate the metal, ie to remove as much oxygen as possible from it;

- if necessary, the most advanced desulphurisation of the metal is carried out;

- adjust the heating of the oven to a temperature that allows a normal casting of the melt 43.

The invention provides for two stages of deoxidation: by diffusion and precipitation.45

Diffusion deoxidation means that the metals in the bath are depleted in oxygen.

Precipitation deoxidation means adding deoxidants directly to the bath.47

Diffusion deoxidation consists in the fact that the deoxidation reactions take place in the slag and at the metal / slag boundary.

RO 128995 Β1

Diffusion deoxidation is based on the law of oxygen distribution between metal and slag, and is carried out in the furnace with basic lining and under white slag.

Obtaining the white slag consists of the deoxidation of the slag initially with carbon, until the first signs of discoloration of the slag, by adding in the oven a mixture of reduction consisting of the following dry and ground materials, class 0.5 mm: 5 parts lime, 1 part calcium flower, 1 part coke and 2 parts mangal.

The second mixture of dry and ground materials, class 0.5 mm, consists of: 5 parts lime, 2 parts FeSi (with 75% Si), 1 part calcium fluoride, 1 part SiCa (with 35% Ca).

The mixtures occur on the slag several times, until the slag becomes white; the quantity of the two mixtures depends on the capacity of the oven and varies within the limits of a

1 ... 3% by weight of the oven load.

The white slag must be kept until the end of the process, that is, until the melt has been removed from the oven.

A few minutes before unloading, the deoxidation proceeds by precipitation, giving aluminum baths between 0.2 and 0.5 kg / t and SiCa (with 35% Ca) between 0.5 and 2.5 kg. / t of load, after which the bath is mixed.

One concern is that before discharge, the slag is fluid, strongly basic, which also ensures advanced sulfur removal.

In samples, samples are taken for the analysis of gases present in the metal, namely: oxygen, nitrogen and residual hydrogen.

The following maximum values should be analyzed for gas analysis: oxygen 12 ppm, residual hydrogen 1.5 ppm and nitrogen 50 ppm.

Also, samples are taken for slag analysis, determining, by fluorescence X-ray diffraction, the oxide components and fluorine: SiO ₂ , CaO, MgO, FeO, CaF ₂ , P ₂ O ₅ , and metal sample at shell for quantovac analysis of the metal elements present in the bath. The temperature of the bath with immersion thermocouple Pt-Pt 10% Rh is taken, and if the temperature is between 1300 and 1350 ° C, preparations are made for the discharge.

Preparations for melt discharge

Ladle

The casting pot, whether it has a stopper, fig. 15 and 16, or with drawer, fig. 17 and 18, is made of a sheet blanket, lined inside with refractory materials, bricks or refractory concrete.

The mantle is supported by a ring (belt) provided with two spindles by the side hooks of the yoke, which in turn is attached to the main hook of the crane, as shown in fig. 14.

at the bottom, the pot sheath is provided with two side plates, welded by the metal sheath of the pot and which have an axis trapped between the two plates, from which the auxiliary hook of the crane can be hung, to allow the pot to tilt, in order to clear the cargo through the pot bump.

In the bottom masonry of the pot, for the flow of the metal, there is the flow hole composed of a nozzle, a flow piece, which can be executed in one or two pieces. These parts are made of super-light molded bricks, magnesite bricks, or carbon-carbon shaped blocks, or graphite-shaped blocks.

in FIG. 15 shows a molding pot with stopper, in which a represents a section through the pot, and b is the outline of the pot - the metal part. In this type of pot, the casting hole is closed and opened with the aid of a plug, in which the plug represents a portdop bar made of a steel rod, clad in tubes shaped from an aluminum socket.

RO 128995 Β1

Details for closing and building the pot with refractory material, next to the 1 casting hole in the bottom of the pot, are shown in fig. 16, in which: 4 represents the pouring hole, which is closed or opened by means of a plug 5, made of aluminum shank, fastened 3 to a portdop bar 6 of a steel rod clad in aluminum shank tubes 7, fixed with refractory table; 1 and 2 represent the radial bricks for the wall of the pot. 5

The pouring hole is fixed in the brick support, through the taper 8, or with a fixing plate 9, the joint around the hole being filled with refractory mass. The opening or closing of the portdop rod is operated with a lever system.

in FIG. 17 is presented a section through a casting pot with closing-opening 9 with drawer, lined with refractory material, for a capacity of 125 t steel, in which: 1 super-light bricks, 2 - aluminum shingles, 3 - shingles. 11 in FIG. 18 are presented details for closing and opening the pot with drawer, in which the upper fixed plate with the flow hole and the lower mobile plate with the 13 flow hole are observed.

The opening-closing system is pneumatic or hydropneumatic.15 Before casting, the casting pot must be heated to at least 1250 ° C.

Casting assembly17

The casting assembly is composed of ingots, central funnel, casting bridges and plates (bottoms) .19

The ingots, casting bridges and plates (bottoms) are cast from gray cast iron.

The ingots can be normally conical or inversely conical.21 in fig. 19 are shown ingots, which may have a square, rectangular or polygonal section.23

Also, in FIG. 19, the following types of ingots are presented:

- the normal conical type without masonry; 25

- the type with masonry;

- the inverse conical ones always have maseloteria, which can be separated c, d, or make 27 common body with the ingot;

- at the foot, the ingots can be opened a, b, c or closed, the latter being able to have a 29 orifice d and e, which serves to remove the ingot and which takes the casting on foot has a socket bush, which provides a metal jet. well centered. When casting upwards, the hole 31 closes with a plug.

In the present invention normal tapered ingot molds are used with top casting. In this case 33, the ingots are opened downwards and are placed on plates (bottoms), if the casting is done individually or on double casting bridges, etc. 35

There is the possibility of indirect casting, at the bottom of the ingots, using a central funnel and then the hole of the pouring pot is brought into the axis of the 37 pouring funnel and the liquid metal penetrates to the bottom of the ingots, fig. 20.

in FIG. 20 is presented a section, through a double bridge, in which, 3 - represents the bridge 39 itself, and 3 'an upper plate, which reduces the danger of metal piercing, helps to break the tails of the ingots and ensures a good centering of the ingots with metal. 41

Also, in FIG. 20, 1 - represents the directly conical ingot, 2 - masonry, 3 casting bridge, 5 - star brick provided with a hole near each channel of the 43 bridge.

In the channel, the intermediate channel tubular bricks 6 with hole 45 are mounted end to end, for conducting the metal in ingots. A network of tubular bricks is formed in connection with the central funnel 4, in which the refractory funnel 9 is mounted. Fitting 47 of the tubular bricks 8 is also done end-to-end.

RO 128995 Β1

The ingots are painted with lime milk or dehydrated tar and are preheated to 120 ° C, the temperature is measured with the contact thermocouple.

With the help of the crane, the pot is brought into the oven's casting pit.

The electric oven is disconnected from the mains and tilted so that the liquid batch from the oven flows into the pot. When the clearing is completed, coke or charcoal dust is sprinkled on the surface of the melt. The crane takes the casting pot loaded with the liquid metal, either with a stopper or with a drawer, and brings it to the casting assembly, fig. 21. If the casting is done directly in the ingot mold, it is necessary to center the pot molding hole in the ingot axis.

After casting the metal, the pot plug or drawer closes the flow hole and the casting pot caught in the yoke hooks is directed to the cylindrical mixer J.

When the pouring pot has reached near the mixer heated to 1300 ° C, the auxiliary hook of the crane enters the device mounted at the bottom of the pot and allows the pot to tilt, so that the slag, which we will call "special slag, can be discharged into the mixer.

After casting, the pot is brought to its original position and guided into the space for the casting pots, where it is cleaned and heated for a new casting.

The electric oven after leaving the pouring pot is brought to a horizontal position, cleaned of certain debris left on the hearth and on the walls, and if necessary, it is adjusted with refractory material and preparations are made for a new batch.

After solidifying the metal in the ingot, extraction of the ingot is performed, ie stripping it from the ingot.

After the ingot or ingots have cooled, they are attached to the special catch hook, fig. 21, and are directed, for the electrolytic refining of gold and silver, a process known and applied in industrial practice.

in FIG. 21 is shown a double casting assembly, in which the metal jet from the casting pot flows into the centered funnel and through the pipes enters the ingots, through the bottom hole of the ingots. In this drawing, the ingots are inversely conical and have masonry.

Also, in the drawing you can also see the pliers, which are hung in the crane hook and after the stripping of the ingots, catch the ingot either to store it or to load it in a means of transport.

At the start of operation of the unit, as well as after each major repair, it is necessary to develop a new electrolyte, for the electrolysis tank. The quantity of electrolyte developed is based on the capacity of the electric furnace and consequently the capacity of the electrolysis tank is designed according to the quantity of electrolyte.

The ionic network can be destroyed not only by the intervention of the solvent, which overcomes the Coulombian forces that are manifested between the ions of the network, but also by the intervention of heat, capable of destroying the order in the crystal and melting it.

The liquid that appears after the melting of the crystal has incomparably better conductive properties than the corresponding solid and is called: saline melt, ionic liquid or electrolyte.

The electrolytes can be oxides, salts, hydroxides or mixtures thereof, all in anhydrous state.

Exceeding the melting temperature, these electrolytes are totally dissociated and as a consequence have a much higher electrical conductivity than the aqueous solutions of the respective compounds.

In Table 3, the chemical compositions expressed in mass percentages of ten types of electrolytes, formed of oxides, are presented; SiO ₂ , CaO, MgO, AI ₂ O ₃ , and fluorine are present in three of them.

RO 128995 Β1

Also, in Table 3, the melting temperature is shown approximately. 1

Table 3

Electrolyte indicator Chemical composition, in% As a MgO AI ₂ O ₃ Yes ₂ CaF ₂ Approximate melting temperature (° C) 1 25-30 8-10 10-20 62-65 1350 2 20 18 62 1345 3 49 11 40 1310 4 20.3 18.3 61.4 1345 5 2. 3 16 61 1165 6 38 20 42 1265 7 23.3 14.7 62 1160 8 55-65 6-10 1.5-3 15-20 5-10 1230-1250 9 20-25 20-25 60-65 1250 10 45-55 15-25 20-30 1250

The electrolyte must have:

- maximum electrical conductivity; 19

- lowest viscosity;

- specific weight as low as possible; 21

- Lack of volatile components at working temperature.

After the calculation of batches, to obtain the composition of the electrolyte chosen, the technology 23 requires that from the automatic dispensers 48, 49, 50, 51 and 58, fluorine, quartzite, bauxite, magnesite and burnt lime pass into the dispenser trolley 52, of which these materials are 25 discharged into chibla 53. Chibla 53, as mentioned above, is located on the platform of a trolley 54 and is guided under the crane hook 55. 27

The chibla is raised by the hooks of the yoke and the crane is directed to the three-phase electric arc furnace with pivoting arch. 29

The vault is raised and rotated so that the spindle shaft caught in the auxiliary hook of the crane allows the spool to be tilted so that the spindle materials are introduced by sliding 31 into the furnace.

Follow the operation to return the target on the trolley platform. 33

To start the electric oven, the pivoting vault returns to its original position and the electric oven is connected to the electrical network, thus obtaining the electrolyte, by melting 35 materials. The way of the elaboration process is similar to that of obtaining the gold and silver, with the indication that in the electrolyte elaboration there is only a 37 phase of melting and not deoxidation.

RO 128995 Β1

After melting, a sample is taken to determine the chemical analysis of the electrolyte, which is performed on the fluorescence X-ray diffractometer.

After receiving the result, if necessary, corrections are made, by adding materials, so that the electrolyte corresponds to the analysis originally proposed.

Take the bath temperature with the Pt-Pt immersion thermocouple 10% Rh, which must be at least 50 ^p C higher than the melting temperature of the respective electrolyte.

If the conditions are met, the electrolyte is discharged into a beaker, pre-heated to a temperature of at least 1250 ° C, which is directed to the electrolysis tank, where the electrolyte is deflected by tilting, using the auxiliary hook of the crane, caught in the shaft at the bottom of the pot.

After casting, the pot is brought to its original position and transported to the sector for casting pots.

Electrochemistry is an interdisciplinary science, which can be considered arising from chemistry and electricity, although its content far exceeds the notions of chemistry of substances and of physics of the electric field. Fundamental research in electrochemistry developed intensely at the beginning of the sixth decade of the 20th century, which was oriented towards the field of interface process kinetics and the understanding of the role played by the overvoltage in electrochemical kinetics, the value of the current density in the electrochemical reactions. and developing methods of reaction mechanisms.

The metallurgy is inextricably linked to electrochemistry and it cannot be lacking in this, be it electrodeposition of metals or alloys obtained from aqueous, non-aqueous or melt solutions.

The study of electrochemistry in particular and the physico-chemical one in general is of particular importance for the industrial elaboration of metals, whose deposition potentials are much more negative than of hydrogen, which prevents them from being obtained by electrolysis in aqueous environment such as: aluminum, magnesium, calcium, or alkali metals.

lately, the electrolysis of the melts is also applied to obtaining hard fusible metals such as titanium, zirconium, molybdenum, tungsten, beryllium, niobium and other metals.

The electrolysis of the melts is economical, when the electrolyte temperature allows separation of the metal in the molten state, so that it can be extracted.

however, metals with high melting temperatures are obtained in the form of burettes or powders, which sometimes remain in the electrolyte.

An electrolysis tank is supplied with electricity from high voltage networks, through a 110 kV station, which has an isolated gas switch, from which the energy passes through distribution bars to a transformer, where the grid voltage power supply is lowered to a value of 30 ... 60 kV, followed by the transformer-rectifier group provided with an automatic gross voltage adjustment, made with a step load adjustment switch and a fine voltage control, continuously with a range of the order of 40 ... 60 V DC.

The rectifier can be cooled in two ways: with air or with liquids (water or oil).

For measuring the consumed electricity, on the DC side, special transducers with the secondary 1 V or 1 A are provided, which are mounted on the DC bars leading to the electrolysis tank.

Choosing the optimum electrolyte composition is one of the main reserves of increasing current and energy efficiency.

The energy consumption in the tank is due to:

- losses in the form of heat emission in the environment;

RO 128995 Β1

- the electrochemical reaction and depends on the current efficiency, 1

- the energy consumed in the current conducting bars and depends on the current density used.

Electrolysis tanks, in which the process of electrolysis in the melt takes place, have the following main components: 5

- the infrastructure in which the alloy and accompanying metal elements are produced and collected, 7

- the superstructure, which aims to support the anode assembly and the various devices used in the technological process, 9

- electrical conductors, which connect the anode and cathode of the tank to the electrical installation; 11

- the control, control and supervision equipment of the electrolysis process with modern and adjustable automatic systems, for a stable operation from the technical point of view13 and of the composition of the bath.

The infrastructure of the tank, according to fig. 22, is formed of a metal drawer 1, which is usually of rectangular section. The casing of the basin is made from a self-supporting construction with a metal bottom, made from a sheet with a thickness that is a function of the capacity of the basin.

The assembly of the tank is done by welding or another process with vertical and horizontal reinforcements19 and the bottom solidarity is executed with profiled, longitudinal and transverse metal beams.21

The supporting columns of the vessel are dimensioned to support without gravity the gravitational loads, that is: the weight of the drawer, the refractory masonry, the metallic refractory material 23, the liquid alloy and the liquid electrolyte, and possibly the refractory vault, if it is seated. 25

The interior of the metal casing comprises the refractory masonry of the glass and the side walls.

The masonry of the glass is made as follows: on the metallic bottom is made the thermal insulation 27 made of ceramic fiber fabric plates 2, over which a layer of chamomile powder 3 is placed and then a row of porous chamfer bricks on width 4, compactly built. with mortar 29 refractory.

After the insulation is dried, the masonry is continued with a layer of magnesite granules31 mixed with dehydrated tar 5 and then two to four rows of normal magnesite bricks 6, depending on the capacity of the vessel.33

The perfectly dry bricks are built without mortar, with joints smaller than 0.5 mm, which are filled with magnesite dust.35

Above them is printed a layer of carbon mass 7, cast in a hot state, ensuring the horizontal surface of the seating surface of carbon blocks 37 precoated 10.

Each carbon block has a longitudinally profiled channel, usually in the tail of 39 swings.

The cathode of the vessel is made by assembling several carbon blocks on a 41 steel cathode bar 8. The free space between the channel walls of the carbon blocks and the cathode bar of steel is filled, for sealing and electrical contact, with printed carbon mass and 43 baking at 1150 + 10 ° C.

Above carbon blocks 10, carbon mass 13 is stamped to be 45 baked at 1150 ± 10 ° C.

RO 128995 Β1

The casing of the vat is provided with outlets for the ends of the cathode bar, having at its ends an insulating ceramic casing 9

The casing of the vat on the sides is insulated with ceramic fiber fabric plates 2 and above the level of the vat of glass, there are two rows of magnesite bricks on the side 11, between which is placed a layer of magnesite granules, mixed with dehydrated tar 12.

On the inner sides of the side masonry are placed carbon side plates, precoated, cathodic 14, fixed to each other inclined, to make the crucible of the vessel. Between the side cathodic carbon plates 14 and the masonry formed by the magnesite bricks 11, carbon mass 13 is printed in successive layers, after which it is baked at 1150 ± 10 ° C.

Next, a new layer of carbon mass 13 is stamped on the carbon plates, which is to be baked at 1150 ± 10 ° C.

The drying and heating of the electrolysis tank is done with methane gas burners, initially with a small flame and gradually increasing the flame, so that within 48 hours the heating process will be completed, according to a previously prepared graph.

Both the carbon mass on the hearth and the lateral one have the role of sealing and electrical contact with the refractory alloy metal plates 15, both on the hearth and on the side walls.

The role of refractory metal plates is to avoid the contact of the liquid alloy with the carbon in the carbon mass or the carbon blocks and plates, in order not to produce the carbide of the liquid alloy.

The cathode refractory metal plates, as well as the embedding of the precycled carbon anodes into metal containers, comprising the lower, upper and lateral surfaces are made from one of the refractory alloys whose chemical composition, expressed in mass percentages, is shown in table 4 and have the indicative from 1 to 7.

In order for the anodic refractory metal plates to withstand the intense oxidation process at high temperatures, they are covered by spraying, electrodeposition or by other coating processes with a protective layer, consisting of: MoSi ₂ , WSi ₂ , or ZrBe ₁₃ , Zr ₂ Be ₁₇ , NbBe ₁₂ , Nb ₂ Be ₁₇ , Nb ₂ Be ₁₉ , TaBe ₁₂ , Ta ₂ Be ₁₇ , TiB ₂ , ZrB ₂ .

The metal plates executed from the refractory alloys presented in table 4 or from the austenitic refractory steels presented in table 5 are welded with the electrode type E. 25. 20.

Table 4

Indicative others Chemical composition, in% Ti Mo Nb Zr W Your The base 1 5-9 10-20 Nb 2 1-3 10-14 25-29 Nb 3 6-10 3-5 0.4-0.8 4-6 8-18 Nb 4 6-12 5-9 16-22 Nb 5 0.5-1.5 8-12 Your 6 0.5-1.6 0.10.5 Mo 7 2-6 2-6 W

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ro ___i. _ Σρ ^ - ~ j— Σρ> _ GTI oo 8 ^ cn oo CH CO CO cp X cp X OO on Cn > < C ~> c5 cn θ oo OO c5 co θ <O> oo Fo on ϋ K> cn cn Ko CO Ko on co JCZ> IZX oo x < IZx cz> OFT CO czo X czo czo co> <S> [x ΓΟ --J CZO co izx l / X ¹ x l / X <Η ~ cn l / X l / x r * o L / X CH IZx IZx J / N IZx cz> CZO cz> CZO cz> CZ3 s co> P ^ ΓΟ P = - CJ1 cn ΟΓΪ on izx IZx IZx fzx CO A CO a CZO czo CO CO » CO R a oo OO a czo CZO cz> : __ F ^ O ΓΟ 4 ^ - T ^ GO » t = x ro RLO ΓνΟ C5> oo ΓΌ CX> kz> rxo on N S £ ξδ FgO -Pî- cn oo oo RLO C £ O CO oo IXZ CO C ~> oo <_n IZx CZO OT

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CJ-β

EN 128995 Β1 in general, electrolysis tanks are equipped with pre-cast carbon anodes 16, of parallelepiped shape, the dimensions of which depend on the load of the electrolysis tank.

As known, these anodes work under conditions of high oxidability at high temperatures, taking place during electrolysis a continuous depolarization of oxygen.

Graphite anodes are constituent parts of electrolysis tanks, which are consumed during the electrolysis process.

The anodes used in melting electrolysis must meet the following conditions:

- the highest purity and the absence in particular of the cations, which can be discharged at the cathode concomitantly with the metals that are the object of electrolysis;

- the ash content does not exceed 0.5%;

- the lowest porosity;

- as high stability as possible with respect to oxygen or to the gases emitted at the anode at high temperature.

In general, these conditions are met by synthetic graphite electrodes.

The raw material used in the manufacture of anodes is: petroleum coke, tar coke and anode residues resulting from electrolysis.

The anodes used in melting electrolysis are of two types:

- calcined anodes, when their baking and graphitization takes place previously, being a technological process independent of the electrolysis process;

- Soderberg anodes in paste form, when baking and graphitizing takes place in the electrolysis tank.

The details of the chemical reactions involved are not yet fully elucidated, but it is certain that the oxygen ions from the dissociation of the oxides present are electrolyte discharged to carbon dioxide, with the formation of anodic gases containing mainly CO ₂ carbon dioxide and small amounts of CO carbon monoxide. .

It is known that, for example in the industrial process of manufacturing aluminum, precocious carbon anodes must be changed at regular intervals, after they have been consumed in the proportion of 2/3 or 3/4 of the original size.

Occasionally, at precocious carbonic anodes, due to the heat shock, exfoliation appears at the lower ends or vertical or horizontal cracks and in these cases it must be intervened.

On the other hand, in the process of electrolysis, in the melts an important quantity of compounds with negative impact on the environment is formed, by producing gases such as: CO ₂ , CF ₄ , CO etc.

Studies are known, on the finding of more stable chemically inert anodes and electrochemistry, to replace precocious carbon anodes. According to the invention, replacing precocious carbon anodes with inert anodes results in significant reductions in production costs, reduction of energy consumption and the most important factor is the reduction of environmental pollution.

The technical problem, which is solved by the invention, consists in the production of inert anodes, by the embedding of carbon dioxide precoated in metal containers made from refractory alloys, presented in table 4, or from metal plates executed from one of the brands of laminated austenitic refractory steels or forged, as shown in Table 5, as shown above.

The inert anode is also made of a weldable carbon steel block, obtained by forging or molding from the OT 40-1 steel mark containerized by refractory metal plates mentioned above.

The chemical composition of the OT 40-1 steel mark is: C 0,10 ... 0,20%; If 0.25 ... 0.50%; Mn 0.40 ... 0.80%; P <0.050%; S <0.050%;

The connection between the two metals can be made by metal-thermal welding or with 1 type of electrode E, 25. 20 or by another process.

The embedding of carbon dioxide into precast containers is done using carbon stamped mold3 and molded, for sealing and obtaining a perfect electrical contact.

Containerized anodes are considered inert anodes, as they have: 5

- insolubility in the molten electrolyte;

- resistance to the action of anodic oxygen, 7

- low electrical resistance and low contact resistance with the metallic current conductor, 9

- lack of contamination of the liquid alloy deposited at the cathode;

- low overvoltage, for the discharge of oxygen ions; 11

- thermal stability and thermal shock resistance;

- saving precooked carbon dioxide, which in fact represents only 13 initial quantities of container:

- long service life, without anode change operations, which disrupts the technological process and causes thermal imbalance;

- elimination of the production of polluting carbon dioxide gases, 17 carbon monoxide and other gases.

The bath in the electrolysis tank is composed of two layers that are immiscible between them: on the one hand, the liquid alloy and _,; on the other hand, the liquid electrolyte.

The superstructure of the electrolysis tank supports the anodic assembly, aiming as 21 the distance between the lower surface of the anodes and the surface of the liquid alloy, ie the interpolar distance, to be maintained at the optimum value, for the normal unfolding of the 23 electrolysis process.

The superstructure of the electrolysis tank also comprises the following 25 subassemblies:

- the pillars supporting the fixed frame and the anode assembly; 27

- the electromechanical device for vertical displacement of the anode assembly;

- a number of sectors of pivoting bolts above the electrolysis tank; 29

- the gas collection hood resulting from the electrolysis process.

The electrolysis tank, according to fig. 22, is equipped at the top with a refractory vault 31, which represents, in this case, the most requested thermal and mechanical element, and which contributes to the reduction of thermal losses, and as a consequence to the increase in the efficiency of the tank 33.

From a constructive point of view, as shown above, the vault is made up of 35 sectors of movable and independent vaults, allowing them to be lifted and rotated during the technological works in the basin, which include: changes of anodes, 37 introduction of the molten electrolyte and of the "special slags, temperature measurements with Pt-Pt immersion thermocouple 10% Rh, sampling, extraction of molten alloy, etc. 39

The vault sectors are constructed of chromomagnetic refractory bricks, specially designed for vault 24, bricks that are supported externally on refractory bricks of 41 support 23 and which in turn are supported by a metal ring 22, which rests on the metal casing of the vessel. or on a tank-independent construction that allows 43 individual mobility of the vault sectors.

Sealing elements of welded steel plate 45, water-cooled 25, are installed on the refractory vault sectors, which, on the one hand, cool the most thermally demanded part of the vault, as mentioned above, and on the other On the one hand, 47 hot gases cool technologically, having a beneficial effect on anodes.

RO 128995 Β1

The cooling elements are mounted on the vault in such a way as not to impede the vertical movement of the anodes.

The containerized anodes are mounted on an anodic rod made of refractory steel 18, fixed by the movable frame of the vessel, allowing them to be removed and replaced in the electrolysis process, if applicable.

The interpolar distance adjustment is made by moving the movable anode frame 19, from which the rods with containerized anodes are fixed, by the vertical displacement device of the anode assembly.

in FIG. 22, the fixing system between the anode and the anodic rod of refractory steel is also observed.

Above the entire superstructure of the electrolysis tank, there is a hood with the necessary piping to collect the gases and send them for dry cleaning.

The dry process of purifying the existing compounds in the gases emitted in the electrolysis tank involves an installation in the form of reaction modules, corresponding to a filter bag assembly.

Periodically, through a pipeline system, low pressure compressed air is injected to remove the dust layer deposited on the canvas of the filter bag and subsequently the gases are subjected to wet scrubbing.

According to the invention, the process and the electrolysis installation have the following advantages:

- the lack of formation of the crusts in the electrolysis tank, as in the case of obtaining aluminum, by the fact that, in this case, a rhythmic feeding with "special melt slag is made and as a result leads to the absence of dust in the gases produced;

- pursues, from an ecological point of view, the protection of the environment.

After the metal part (gold and silver) has been poured into the casting assembly, the casting pot with the slag obtained in the electric arc furnace is directed to the mixture or where it is discharged for storage.

The cylindrical mixer, shown in fig. 23, is lined inside with refractory material, in which:

- the level of the slag stored;

- the casting pot that transported the slag to the mixer;

- mouth for slag casting;

- opening for slag casting;

- the burner;

- casting pot for slag transport from mixer to electrolysis tank,

- the gear;

- mechanism for lifting the lid of the mixer;

- the lid in the raised position.

The addition of "special slag in electrolyte will be at least 5%. Through experiments, the maximum value will also be established.

Measures must be taken to prevent the anodic effect from occurring, which is manifested as a result of the decrease of the "special slag content in electrolyte and which would lead to:

- the sharp decrease of the current intensity;

- increasing the voltage to the voltage value under normal electrolysis conditions.

In this situation, the control program for extinguishing the anode effect is given and the tank is fed with "special slag.

The control unit creates the possibility of automatically conducting the electrolysis process using the microcomputer.

EN 128995 Β1 in the electrolysis process, measurements must be performed at well-defined intervals of 1, which include: temperature in the electrolysis tank, chemical composition of the electrolyte, the height of the cathode alloy, the interpolar distance and continuously the electrical voltage 3 and current intensity in the tank.

These parameters help to correctly diagnose the technological state of the vessel and allow 5 measures to be taken to correct and supervise the electrolysis process, in order to achieve an optimum gait, that is to say a thermally stable operation and of the composition of the bath 7, at as high a current output as possible, which corresponds to optimal energy consumption. 9

The electrolyte level must be permanently maintained at an optimum level, through the technological bath correction operation. 11

A pneumatic mail system must be provided for the transport of samples to the laboratory, and the result of the analyzes must also be displayed on the monitor in the hall of the electrolysis tank. 13

The dosage of the chemical composition of the bath must be done rapidly, by X-ray diffraction by fluorescence, (by the melting procedure or by the compaction procedure of the 15 electrolyte sample).

The liquid alloy deposited at the cathode in the electrolysis tank, according to a rigorous graph 17 respected, is extracted by means of an extraction casting pot with connection to the vacuum system. 19

The drained pot is lined with refractory material, the suction plunger is made of zirconium oxide, to withstand the attacking action of molten alloy and 21 molten electrolyte.

The problem of the vacuum suction pot of molten alloy is known and applied in 23 industry, as is the case with aluminum.

From the drained pot, the alloy is poured into a molding pot with a stopper or drawer and is directed to the casting assembly for pouring the alloy into the ingot mold.

After the ingot is cooled, the ingot is striped and sent for electrolytic refining. The second variant, according to the present invention, in order to optimize the technological flow, performs the unloading of the alloy at the level of the cathodic glass threshold of the electrolysis tank in a 29 casting pot, which after completion of the clearing is directed to the casting assembly, for casting in the ingot mold. of the alloy. 31 in order to achieve the unloading of the alloy at the base of the cathode glass, the electrolysis tank has a longitudinal section inside, which is shown in fig. 24, an inclination of 33 2 up to 8 ° from the horizontal, up to the outlet.

The outlet of the alloy is an opening in the wall of the vessel 35 in the axis of longitudinal symmetry of the vessel, the size of which depends on the capacity of elaboration.37

Therefore, near the outlet of the alloy, inside, the metal plate of the refractory alloy is cut in a semi-round shape.39

Also, on the outside of the basin, the metal drawer is also cut next to the outlet in semi-round shape. 41

The evacuation hole of the alloy is lined at the bottom with magnesite bricks, and the top of the hole has a piece of refractory ceramic material, 43 which rests on the magnesite bricks.

This part, which in fact represents the vault of the outlet, is fixed to the interior 45 in the metal plate of refractory alloy, and to the outside it is embedded in the metal casing of the vessel.

The piece is made of: zirconium oxide, graphite, magnesite, molded carbon block or molded and baked carbon mass at 1150 ± 10 ° C.49

RO 128995 Β1

On the outside under the outlet of the alloy is fixed by the metal drawer by screwing, welding or other known means, the drainage gutter made of thick steel sheet and lined with magnesite bricks on the side, in two overlapping rows, with joints smaller than 0.5 mm, without the joints in one row overlapping with the joints in the next row.

Magnesite bricks, which form the lower part of the outlet from the inside to the outside, as the bricks on the outlet trough have the same inclination to the horizontal as the cathode glass inside the tank.

in FIG. 24, the section A-A of fig. 22, representing a longitudinal section on the axis of symmetry of the electrolysis tank, in which the inclination of 2 to 8 ° is observed with respect to the horizontal and then the same inclination, in the lower part of the outlet and the magnesite bricks. on the drain trough.

It is further observed in FIG. 24:

- the upper part of the alloy and electrolyte outlet port 1;

- the magnesite bricks of the lower part of the outlet 4;

- outlet trough made of thick steel sheet 3;

- magnesite bricks lining the drain trough 4;

- cathode steel bars 8;

- cathodic carbon blocks 9;

- cathodic side carbon plates 10;

- carbon mass printed and baked on carbon blocks and side carbon plates 11;

- metallic plates 12 of refractory alloy, for horizontal and lateral plating of the vessel, including for embedding precoated carbon anodes 14;

- refractory vault 13;

- anodes containerized with refractory alloy metal plates 14;

- the level of the alloy 15;

- electrolyte level 16.

Also, it can be observed that, on the outside on the metal drawer, a hydraulic system for closing and opening the outlet opening acts as follows:

- safety metal plate 5;

- guide plate 6,

- the hydraulic actuator cylinder of the safety plate 7.

Also in FIG. 24, the casting pot 18, located on the transport wagon 19, is shown next to the outlet port.

On the electrolysis tank casting platform, suspended on a trolley, moving on the beam of a rotary console, are ready for operation:

- machine for opening the outlet of the alloy, which may be: an electrically operated drill, or a device that uses the electric arc using a graphite electrode;

- machine for closing the outlet of the alloy, which can be electric with piston, or electro-hydraulic.

The machines above, regardless of the drive system, are known and applied in the industry.

According to a chart it must be respected and established by measurements of the level of the alloy in the basin is preparing its release.

RO 128995 Β1 for this purpose, is brought to the platform next to the outlet, the machine of 1 opening of the opening, and next to the outlet, the wagon with the pouring pot, heated to a minimum of 1250 ° C. 3

The hydraulic system for lifting the safety metal plate in front of the hole is actuated.5 when the outlet is open, the machine is removed and the liquid alloy flows into the casting pot.7 at the same time, the machine is brought to the platform. closure of the orifice, ready for operation.9

When the evacuation of the liquid alloy is completed, the machine for closing the orifice with refractory mass is actuated.11

The refractory mass for plugging the flowchart must have refractivity, chemical resistance against electrolyte action and good plasticity.13

Also, the insertion of the clay into the flow mouth must be done under the air pressure of the air.15

Theoretically, the electrolyte is not consumed during the electrolysis process, but losses can occur, in particular, by causing it to unload the alloy.17 Finally, the machine closing the hole is withdrawn from the platform, the hydraulic closing system acting externally. of the hole with the safety metal plate.19

The wagon with the casting pot is directed to the casting assembly, where the casting pot is lifted by the yoke hooks and brought to the casting assembly.21

The casting pot, whether it is with a stopper or a drawer, is open and the alloy flows into the ingot.

After cooling, the ingot is striped and the alloy ingot is sent for electrolytic refining.25

After the end of a working campaign, the electrolysis tank is disconnected from the mains and the electrolyte in the tank, together with the alloy, are laid in a 27-well pot.

After casting the alloy in the ingot, the pot with the electrolyte is directed to a 29 trolley-valve, made of cast iron.

The trolley is painted with lime milk or dehydrated tar and heated to 120 ° C. 31 in this trolley the electrolyte is discharged, which after cooling, becoming a ceramic mass is striped from the trolley and directed, for use in the ceramic and construction industry. 33

After cooling the alloy, the ingot is striped and directed for electrolytic refining.

in FIG. 25 shows the top view of the containerized anodes and the longitudinal section 35 C-C through these anodes.

The fixing system between the anode and the anode rod is made by threading, or another known process 37.

It is specified that in FIG. 25, the thread of the anode rod is of the trapezoidal type.39

The side walls of the electrolysis tank shown in fig. 22, 24, 26, 27, and 28 are inclined between 30 and 60 ° from the vertical axis and are formed, starting from the metal drawer 41 inwards from:

- ceramic fiber fabric plates 2; 43

- two rows of magnesite on width 11, between which there is a layer of magnesite granules mixed with dehydrated tar 12;

- printed and baked carbon table 13;

RO 128995 Β1

- cathodic side carbon plates 14;

- printed and baked carbon table 13;

- metal plates from refractory alloys 15.

The construction of the tank according to the present invention has two variants:

- In a first embodiment fig. 26, the masonry of the side walls is continued with magnesite bricks, eliminating the laterally printed carbon mass and maintaining:

- the side carbon plates 14;

- a thin layer of printed and baked carbonaceous mass 13, for perfect electrical contact;

- metallic plates from refractory alloys 15, and in the second variant the coating is made directly on magnesite bricks with metallic plates of refractory alloy, fig. 27.

The construction of the cathode glass of the electrolysis tank, for both variants, starting from the cathode bar of steel 8 is formed by:

- cathodic carbon blocks 10;

- printed and baked carbon mass 13, on carbon blocks;

- metal plates from refractory alloy 15.

The invention also presents another embodiment of the cathodic glass construction, replacing the cathodic carbon blocks 10 with printed carbon mass 13, followed by its baking at a temperature of 1150 ± 10 ° C, after which the plating with refractory alloy metal plates 15 is performed, fig. 28.

It should be mentioned that the numerical indications in fig. 26, 27 and 28 have the same meanings as those in fig. 22.

The processes, which take place in the molten electrolytes, comply with the general laws of electrochemistry and the succession of ion discharge, coinciding with that of aqueous solutions.

The obtaining of metals by melting electrolysis is characterized by a series of particularities, which are generally due to the high temperature, at which electrolysis is performed, namely:

- increase the speed of secondary chemical processes;

- the finished products can react with atmospheric oxygen, electrolyte, or electrode material;

- new chemicals appear, which increase the number of secondary reactions;

- in the presence of impurities, unwanted chemical or electrochemical reactions may occur.

An important problem in melting electrolysis is the choice of an appropriate electrolyte composition.

The reduction of the working temperature can be achieved by introducing other salts into the melt. These additions must meet certain conditions and have:

- maximum electrical conductivity;

- lowest viscosity;

- specific weight as low as possible;

- not be volatile at working temperature;

- not to increase the consumption of raw materials.

Impurities in the electron may cause depolarization effects.

For example, water absorbed from the atmosphere is one of the main causes of decomposition at relatively low voltage, as well as the phenomenon of hydrolysis, especially pronounced due to the high temperature.

Following hydrolysis, new substances are formed, having different decay voltages than electrolyte.

RO 128995 Bl

The working temperature in the industrial electrolysis of their molten electrolytes is normally 1 higher than the melting temperature of the metal deposited at the cathode.

The separation of the electrolyte metal is one of the difficulties of electrolysis in 3 melts.

The closer the melting point is to the crystallization temperature, the more structured the melting is, and therefore closer to the solid state, near the crystallization temperature, in the molten salt, the small 7 ordered centers, consisting of large coplecium ions, appear. which constitutes an intermediate stage between the melting and the crystalline state, 9 at the moment of crystallization, the mobility of the ions decreases sharply and correspondingly at temperatures lower than that of the crystallization, both the intensity of the current and the voltage 11 at the terminals of the electrolysis tank decrease.

By electrolytic deposition of the metals to the cathode in solid state, their crystallization takes place 13.

The size and shape of the deposited crystals, as well as the macroscopic aspect of the deposit, depend on the conditions and composition of the electrolyte.

The deposition rate and character of the metal deposit obtained during the igneous electrolysis 17 depends on a number of factors, such as: the ion transport rate to the cathode, the potential to deposit the metal on the cathode, the temperature, the current density, and the rate of fixation of 19 atoms in the crystalline network.

The process of electrolysis in molten salts is subject to Faraday's law, but due to 21 secondary processes to electrodes, the amount of experimentally separated substance is always smaller than the calculated one. 2. 3

The current efficiency is ή - m _exp / m _t where m _exp is the mass of the separated substance at the electrode, and m _t represents the mass calculated with Faraday's law, for the same 25 electricity consumption.

The efficiency of the current can also be expressed by the ratio of the quantities of 27 electricity q, theoretically necessary, for the separation, I have grams of substance and q _exp the practically necessary for its deposition. 29

a.

Therefore: 77 (%) = - ^ 100 = - ^ 100 31 <7 _exp ^m t

Another important factor in igneous electrolysis is the interpolated distance, which in practice is 33 centimeters.

Deviations from Faraday's law are due to causes such as: partial dissolution of the metal deposited in the electrolyte; the possibility of parallel cathodic deposition of electropositive or even more electronegative metals than the desired metal; mechanical losses 37 in the electrolysis process, such as: metal entrainment, magnesium case in the slag layer consisting of MgO; volatilization losses. 39

It can be stated that, up to now, the problem of expressing the dependence between the efficiency of currents on the various factors, which determines it: temperature, current density, 41 interpolar distance, electrolyte composition, electrolyte and metal quantity in the bath; the shape of the electrolysis tank did not receive a satisfactory solution. 43

An important factor that the invention has achieved is the way of lining with refractory material of the electrolysis tank, both at the hearth and at the side walls. Further in the invention, the electrolysis tank 45 is provided with a refractory vault, as mentioned above.

All these contribute to a good thermal insulation capable of reducing the losses of 47 current due to the heat transfer, through the side walls of the tank and have a special influence on the current efficiency. 49

RO 128995 Β1

A relationship between the current efficiency and the composition of the anodic gases rich in CO _{2 was found} . The experimental amount determined by the carbon dioxide is smaller than the calculated one, because part of the CO ₂ reacts with the anodic carbon after the equilibrium reaction; CO ₂ + C ~ 2CO, shifted to the right, the higher the temperature around the anode.

Raising the temperature of the electrolyte and the metal leads to the decrease of the current efficiency, which is explained, by accentuating the chemical interaction between the metal and the saline phase. The interaction results in the combination of the metal with the separated products at the anode. For this reason, electrolytic metals must be obtained at the lowest temperature allowed by the system. But, no too low temperature can be chosen, due to the increase in viscosity, resulting in mechanical losses.

The lowering of the temperature, without affecting the fluidity of the electrolyte, is usually achieved by the addition of salts such as chlorides or fluorides of alkali metals, or alkaline-earth metals, containing cations much more electronegative than the metal to be deposited, These additions do not lower the temperature alone to melt the electrolyte, but also acts favorably on other physico-chemical parameters of the electrolyte; for example, it decreases the solubility of the metal, which increases the current efficiency.

The lowering of the temperature in the electrolysis process is particularly important in the case of metals with high volatility.

The increase of the current density generally produces an increase of the current efficiency and therefore an attenuation of the deviations from Faraday's law, caused by the losses of metal, as is the case with the electrodeposition of aluminum and magnesium.

Current densities applied to industrial ignition electrolysis are much higher than densities in the aqueous environment, such as 0.75 ... 1 Α / cm ² for aluminum and magnesium (anodic density) and up to 30 ... 50 A / cm ² for calcium and beryllium (cathodic current density).

But a too high current density increases the voltage drop in the electrolyte layer and with this the ohmic IR polarization and obviously an increase in electricity.

With the increase of the cathodic current density, the anodic density increases accordingly; or, in many cases, even at relatively low anodic densities, the anodic effect appears, which disturbs the normal flow of the electrolysis.

Also, at current densities that are too high, it is possible to develop secondary processes, such as depositing other metals than desired.

The effect of inertial distance on the electrolysis yield can be explained by the solubilization of the metal in the electrolyte and by its reaction with the gaseous products from the anode. Therefore, as the distance between the electrodes increases, the current efficiency increases. An increase over a certain limit of the distance between the electrodes leads to an increase in the losses of electricity, both by chemical polarization and by the heating of the electrolyte, which negatively influences the current efficiency.

The composition of the electrolyte influences the value of the current efficiency. One of the essential causes of the deviation of the current yield from the theoretical value is the solubilization of the metal in the electrolyte, followed by the oxidation of it by the electrolysis products from the anode.

The addition of salts, containing more electronegative cations, compared to the metal to be deposited, reduces the solubility of the latter and thus acts favorably on the yield.

The thickness of the layer and the volume of the metal and of the electrolyte also influence the current efficiency.

RO 128995 Bl

The greater the thickness of the metal layer, the lower the temperature of the bath 1, and the metal losses are lower and the secondary reactions are lower, and the current efficiency is higher. 3

Also, it was found that in the presence of their oxides, the anode gases are electrically positive charged and are rejected from the surface of the anode. 5

The release of gas is continuous in the form of small bubbles. In the absence of oxides, these gases have a negative electrical charge, being retained on the anode surface, forming a 7 insulating gas film.

The potential at which the anode is polarized also has an influence on the appearance of the anode effect 9 and then the gas bubbles are better retained on the anode surface, the greater the polarization of the electrode. 11

Of the discharge potentials of fluorine, chlorine, bromine, or oxygen ions, the most positive is fluorine.13

This explains why the anodic effect appears much easier in fluoride-containing electrolytes compared to oxide-containing electrolytes.15

The CF ₄ carbon flowered compounds insulate the molten electrolyte graphite anode and soon the anodic effect is installed.17

It is known that in the case of alumina electrolysis, in order to obtain alumina, as the electrolysis progresses, the alumina content in the melt decreases continuously and correspondingly the electrode potential moves to more positive values, making it possible to discharge fluorine-containing ions. 21

The anodic effect occurs if the alumina content of the electrolyte has fallen below 2%. In addition to the findings regarding the formation of the gas film around the anode, it may be assumed that there is an anodic superpower, arising from the disappearance of oxygenated compounds from the electrolyte. 25

Therefore, the critical current density can be considered as a diffusion limit current density of oxygen-containing ions. 27

The anodic effect is desirable not to occur, as it leads to a considerable increase in the specific consumption of electricity, as well as to electrolyte losses through volatilization. 29

Anodic gases also contain, in addition to CO ₂ , CO, and fluorinated volatile products, which are evacuated and neutralized 31

The anodic effect

At the electrolysis of melts, at one point, a phenomenon called anodic effect 33 appears. The appearance of the anodic effect is accompanied by a characteristic noise, due to electrical discharges and the appearance of a light ring. 35

The intensity of the current decreases sharply, and the voltage of the electrolysis increases very much, being 5 to 10 times higher than that under normal conditions of electrolysis.37

It has been found that the anodic effect occurs at a certain current density, called critical current density and which has a characteristic value for each electrolyte.39

Therefore, it was assumed that the appearance of the anode effect depends on the amount of gases emitted at the anode.41

If these gases are not removed quickly enough, they form a more or less continuous gas film, which will separate the anode from the molten electrolyte and thus the passage of electric current 43 is stopped.

The gas bubbles of the anode products are retained on the anode surface, which is separated from the electrolyte, or a defective wetting of the anode surface is observed by the electrolyte.47

This leads to a concomitant increase in the current density of the node, because not all the surface of the anode implanted in the melt is in contact with it.

RO 128995 Β1

When the current density at the anode exceeds a certain critical value, the anodic effect appears. the critical intensity, at which the anodic effect appears, corresponds to a critical density i _er = defined by: ς = - A / cm ² where, s _a is the surface of the anode in contact with the electrolyte. ^Saddle

The critical density value depends on a number of factors, such as the composition of the molten phase and the gaseous phase, the presence in the electrolyte of some active surface ions that modify the interfacial voltage at the anode / electrolyte limit, the anode material and the electrolyte temperature.

An amount of gas may also appear due to volatilization or decomposition of the electrolyte, as a result of local overheating.

The appearance of these gas films plays a role in the appearance of the anodic effect, but the mechanism of the process is much more complex.

Basically it is found that the critical current density is lower, the higher the electrolyte purity.

In the presence of oxides, the anodic effect appears at much higher current densities, which is explained by the fact that the anode wetting is much better.

Also, it was found that in the presence of oxides, the anode gases are electrically positive charged and are rejected from the anode surface.

The release of gas is continuous, in the form of small bubbles. In the absence of oxides, these gases have a negative electrical charge, being retained on the anode surface, forming an insulating gas film.

The potential at which the anode is polarized also has an influence on the appearance of the anode effect and then the gas bubbles are better retained on the anode surface, the higher the polarization of the electrode.

Of the potentials for the discharge of fluorine, chlorine, bromine or oxygen ions, the most positive is fluorine.

This explains why the anodic effect appears much more easily in electrolytes containing fluorine than electrolytes containing oxides.

The fluorinated compounds of carbon CF ₄ insulate the graphite anode from the molten electrolyte and soon the anode effect is installed.

It is known that in the case of alumina electrolysis to obtain alumina as the electrolysis progresses, the alumina content in the melt continuously decreases.

The anodic effect occurs if the alumina content of the electrolyte has fallen below 2%. In addition to the findings regarding the formation of the gas film around the anode, it can be assumed that there is an anodic superpower, which appeared due to the disappearance of oxygenated compounds from the electrolyte.

Therefore, the critical current density can be considered as a diffusion limit current density of oxygen-containing ions.

The anodic effect is desirable not to occur, as it leads to a considerable increase in the specific consumption of electricity, as well as to electrolyte losses through volatilization.

For the normal functioning of the electrolysis process, the following measures must be taken:

- correction of the electrolyte composition, by taking samples and analyzing them;

- periodic feeding with "special slag to prevent the anodic effect from occurring;

- the constant maintenance of the interpolar distance;

- it is desirable that the frequency of occurrence of the anodic effect is as rare as it leads to an increase in the consumption of electricity, as has been shown and to the partial decomposition of the electrolyte;

RO 128995 Bl

- the resulting gases are aspirated and neutralized in the spray tower with a solution of sodium hydroxide 1. Anodic current density is the basic feature of a type of tank

The average voltage of an electrolysis tank represents 2.5 to 7.5 V and this adds up all the voltage drops in the electrical circuit of a tank.

The variation of the concentration "special slags in the electrolyte must be between 3 and 7%, and if it falls below 2%, the cathodic effect is triggered.

An example of the application of the invention is given below.

The ore extracted from the mine with the average chemical composition: AI ₂ O ₃ 0.54%; SiO ₂ 72.28%; 9

0.03%; MnO 0.23%; Fe 3%; Pb 0.13%; ZnO 0.11%; At 1.4 g / t; Ag 11.6 g / t and other elements such as: As, V, Ti, Ga, Cr, Co, Ni, Bi, Sn, Mo, W, Ge, In, are brought to the surface 11 in wagons, and with the help of some The conveyor belt is loaded into the railway wagons.

The railway wagons are towed by a locomotive, on a railway station, built 13 above the warehouses, on which rail tracks are mounted and the wagons are unloaded in warehouses. The ore from deposit 1, through the rotary feeder, is taken over by a conveyor belt 15, which supplies the working hopper 6.

Following is the crushing, grinding and grading of the crude ore, during which the concretions are sold.

From the working hopper 6, the ore is passed over the vibrating grid 1.1, with 19 19 80 mm mesh. From the vibrating grate 11, the ore with a granulation grade +80 mm is passed into a jaw crusher 15 and from here on a vibrating sieve 20 with Φ 40 mm mesh. 21

Also on this vibrating sieve 20, with a conveyor belt is also brought the class -80 mm below the vibrating grate 11, and the class +40 mm is recycled to the jaw crusher 15.23

The -40 mm class is taken from a conveyor belt and taken to the conical crusher 25 and from here on the vibrating sieve 30 with Φ 3 mm meshs.25

The +3 mm class is recycled to the conical crusher 25, and the -3 mm class is passed on a conveyor belt to the waiting bunker 35.27

With the help of the mechanical hopper of the waiting hopper 35, the broken and graded ore is passed into the automatic dispenser 47 and from there into the dispenser trolley 52, of which 29 are discharged into the chute 53.

Chibla 53 is placed on the platform of a trolley 54 and is guided under the hook 31 of the crane 55 which supports the yoke with the two hooks.

with granulated ore from furnace E, for burning sulfur from sulphide ore. The combustion temperature of the sulfur is between 750 and 800 ° C, and the combustion is carried out 35 in a multi-storey type Herreshoff oven with 8 floors.

The ore is brought into the bunker sal of the furnace, from where with a helical conveyor, 37 driven by a motor with gearbox 6, it enters the upper part of the furnace through an inclined tube 7. 39

The ore -3 mm class is successively passed through all the floors, after which the oxidized granules are taken over by the last arm whose combs direct the ore in the funnel of 41 unloading 9 and thence in wagon 57.

The wagon 57 with the desulfurized material is transported with the crane 55, for 43 the briquetting operation in the respective sector.

The wagon has on the small side a spindle, from which the auxiliary hook of the crane 45 is caught, and the two hooks of the yoke catch the lateral spindles of the wagon, which is reversed in the bunker 59, where the desulfurized ore is loaded into the wagon 60, which 47 it is directed to the briquetting press.

RO 128995 Β1

With the sulfur burning, SO ₂ sulfur dioxide is obtained and some by-products are produced, which are driven by gas in the form of fine particles, such as desulfurized ore, or as vapors of metals or metalloids or oxides with lower temperatures. of volatilization. The fine particles are sedimented in the dust chamber and in the cyclone.

According to a graph, at a certain time, the installation and cooling of the installation, the cleaning of the windows of the multi-storey oven, the pipe, the dust chamber and the cyclone take place.

The magnifiers on the windows and the dust are sent to the plant to recover the existing elements.

In order that the fine ore from the ore is not entrained by the gases produced during the melting in the three-phase electric arc furnace, the ore is brought to the form of briquettes.

For making briquettes, the ore is mixed with a binder, an operation that is performed in a horizontal shaft mixer, with the possibility of rotating the shaft in both directions. The pallets trapped on the horizontal axis have a certain geometry, which allows the mixing to be done both horizontally and vertically.

Thus, the ore with the SBM-20 benzene sulphonic acid hardener SBM-20 in the mixer is introduced into the mixer, while the pallet shaft rotates, and at the rate of one minute mixing, the turanine resin type FR 3 is added. , in proportion of 2.3% to the quantity of granulated ore. The mixing is continued for another 2 minutes, after which the mixture is poured onto a conveyor belt, which takes it to the bunker of the press.

The mixer has the possibility to evacuate the mixture through a central opening and by rotating the blades in both directions.

The mixture is pressed in C 120 steel molds and is executed with a universal ZD 40 mechanical testing machine. The mechanized press is provided with a carousel type table, on which the molds are placed, in order to obtain the briquettes. The briquettes obtained are loaded in wagon 61 and transported to warehouse N for their storage.

Next, the gold and silver processing phase is followed by a three-phase electric arc with a basic lining with magnesite bricks.

Charging the oven with briquettes is done with the help of the trailer. First of all, the bin in the lighter storage area N is loaded with the quantity of lighters depending on the capacity of the oven. The oven allows the vault to be lifted and rotated together with the electrode holders.

The load caught in the crane hook is brought over the oven and close to the hearth. The bena is a metal cylinder closed at the bottom with flexible metal strips, the ends of which are connected by a rope soaked in tar, which burns when inserted in the oven and the basket of the bin opens. Raising the bin, the load of briquettes falls from a low height on the hearth, after which the crane with the bin returns to the warehouse N.

The vault is restored to the furnace like the graphite electrodes, which are lowered until close to the load. The furnace is connected to the mains using the high voltage switch. To ensure a stable arc, it is thrown under the coke electrodes. This measure prevents sudden oscillations of intensity. If the charge from the beginning provides a stable electric arc, the melting is performed with the automatic voltage regulator in the medium voltage circuit. Continue, gradually increasing the power up to 2/3 of the power of the transformer.

Additions of fluxes, fluorine, bauxite, etc., if necessary, are obtained to obtain a fluid and active slag.

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When the entire load has melted, the bath is deoxidized; first, 1 diffusion deoxidation is applied. For this purpose, two mixtures are prepared. The first dry and ground mixture consists of: 5 parts lime, 1 part calcium fluoride, 1 part coke, 2 parts mango. 3 The second mixture, also dried and ground, comprises: 5 parts lime, 2 parts ferrosilicon (with 75% Si), 1 part calcium fluoride, 1 part SiCa (with 35% Ca). Mixtures 5 occur on the slag several times, until the slag becomes white and must be kept so until the end of the elaboration. 7

The quantity of the two mixtures represents 1% of the weight of the load in the oven.

A few minutes before unloading, precipitation is deoxidized, with 9 pieces of 0.2 kg / t aluminum and SiCa (35% Ca) 0.5 kg / t in the bath.

Samples are taken, namely: the sample for the metal in the sample shell, for analysis at 11 quantovac; slag sample for fluorescence X-ray diffraction analysis and gas analysis. 13

If the bath temperature, taken with the Pt-Pt immersion thermocouple 10% Rh, shows 1300 ° C, and the gas analysis indicated: oxygen 10 ppm, residual hydrogen 1.1 ppm and nitrogen 42 ppm, 15 means that all conditions are met. , and preparations are made for unloading the batch in the casting pot with drawer, which has previously been heated to 1260 ° C. For this purpose, the casting pot is brought into the casting pit and the furnace is disconnected and tipped, so that the batch is discharged into the pot. Coke dust is poured onto the liquid bath. 19

After the unloading is completed, the pot is lifted by the crane and brought to the casting assembly. The oven is restored to its original position, adjusted if necessary and is ready 21 for further elaboration.

The normal tapered ingot was previously lubricated inside with dewatered tar and 23 heated to 110 ° C.

The spindles of the pot caught in the two hooks of the yoke are brought with the flow hole 25 in the ingot shaft.

The drawer is open as long as the liquid alloy flows into the ingot, after which the drawer is closed and the pot is directed to the mixer. Arrived near the mixer with the auxiliary hook of the crane, which is caught by the shaft at the bottom of the pot, the pot is tipped and the slag from the pot flows through the beak of the pot in the mixer heated to 1310 ° C, which has the role of storing the slag. After the clearing is completed, the pot is brought to the booth of 31 pots. After cooling, the ingot is striped and the gold and silver ingot is sent for electrolytic refining. 33

After a major repair to the electrolysis tank and after the drying and heating of the tank, it is necessary to develop a new electrolyte in the three-phase electric arc furnace.35 In this respect, the following chemical composition, expressed in mass percent for the electrolyte, was chosen: CaO 23 %; AI ₂ O ₃ 16%; SiO ₂ 61% .37

After drawing the batch calculation, to obtain the electrolyte composition, the technology requires that from the automatic dispensers: 48, 49, 50, 51 and 58, fluorine, quartzite, 39 bauxite, magnesite and burnt lime in the respective quantities must pass into the dosing trolley.

52, out of which these materials are discharged in ch. 53.41

Chibla 53 is placed on the platform of a trolley 54 and is guided under the hook of the crane 55. The chibla is raised by the hooks of the yoke and the crane is directed to the electric furnace 43 with an arch with a pivoting arch. The vault is raised and rotated, so that the shaft chisel attached to the auxiliary hook of the crane allows tilting the chisel so that the chisel materials are inserted into the oven by sliding. Follow the operation to return the target on the trolley platform. 47

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To start the furnace, the pivoting vault returns to its original position as graphite electrodes, and the electric furnace is connected to the electrical grid, obtaining the electrolyte, by melting the materials.

The way of carrying out the elaboration process is like the one exposed to the elaboration of gold and silver from the briquettes in the ore, with the indication that when the electrolyte is elaborated, only the melting and not the deoxidation phase are present.

After melting, the sample is taken to determine the chemical analysis of the electrolyte.

After receiving the result, if it is found that the obtained electrolyte has the prescribed chemical composition and it is not necessary to make corrections, preparations are made for the casting. For this purpose, the temperature of the bath with immersion thermocouple Pt-Pt 10% Rh is taken. If the temperature is 1310 ° C, it means that the conditions are met and the electrolyte is emptied into a beaker, preheated to 1255 ° C.

The crane with the pot is directed to the electrolysis tank, where with the help of the auxiliary hook of the crane caught in the axis at the bottom of the pot, the pot is tipped and the electrolyte is discharged into the electrolysis tank. After unloading, the pot returns to its original position and the crane takes it to the casting pot sector.

The other accompanying metal elements are obtained by the process of melt electrolysis, which is achieved in an electrolysis tank. The crucible of the vessel comprises the cathodic hearth made of a precooked carbon block, which has a longitudinal groove profiled in the swallow tail with a cathode steel bar, fixed with a printed carbon mass and baked at 1150 ± 10 ° C. The tank is equipped with precoated anodes and has an electromechanical device, for vertical movement of the anodic assembly.

Optimum operating conditions were ensured by the following:

- a concentration of "special slag, brought from the mixer, of 4 ... 6% was maintained;

- an interpolar distance controlled automatically, between 5 and 7 cm, was maintained for a temperature operation of 1400 ... 1450 ° C;

- a number of 3 anodic effects per month were maintained through the automatic special slag feeding program;

- the electrolyte level was permanently maintained, through the technological correction of the bath.

The extraction of the metal was done with the vacuum pot self-propelled on the tires. From this pot, the metal obtained was passed by tipping the pot into a pot with a drawer. The pot with drawer was directed to the turning assembly, where the alloy was poured into the normally conical ingot, and after cooling, the alloy ingot was stripped from the ingot and sent for electrolytic refining.

In conclusion, the invention solves:

- crushing, grinding and grading by size of ore and other raw materials;

- elaboration of gold and silver in the three-phase electric arc furnace with desulphurized and briquetted gold-silver ore and its casting as an ingot;

- Elaboration of the electrolyte in three-phase electric furnace with arc of raw materials, prepared granulometrically;

- obtaining metallic elements accompanying in the electrolysis tank, by melting electrolysis and casting the alloy obtained in the form of ingot;

- recovery of solidified magnifying glasses from multi-storey oven glasses;

- dust recovery from the dust chamber, from the pipe and cyclone and from the silicone and graphite bags from the dry treatment of sulfur dioxide.

Further processing by electrolytic refining of the gold and silver ingots cast from the three-phase electric arc furnace, the alloy ingots cast from the electrolysis tank, as well as the processing of wolves and powders from dry scrubbing of sulfur dioxide are not subject of this invention.

Claims (12)

Claims 1 1. Process for obtaining gold and silver and other metallic and non-metallic 3 accompanying elements from gold-silver deposits and ores, which consists of granulometric preparation of the ore by grinding and grading the ore according to dimensions on 5 grates, crushing, mixing and dosing, (BB), where materials other than fluorine are passed over the grids (11,12,13 and 14) which have 7 mesh Φ 80 mm and from these grates, the class +80 mm, as well as fluorine in the working bunker (7), pass through the jaw crushers (15,16,17,18 and 19), from where the grade-80 mm on the grating passes 9 on the vibrating screens (20, 21, 22, 23 and 24), as the class - 40 mm resulting from the jaw crushers (15,16,17,18 and 19), the +40 mm class is recirculated to the 11 jaw crushers (15,16,17, 18 and 19) and the -40 mm class from the sieve vibrators (20, 21, 22, 23 and 24) pass into the conical crushers denoted by (25, 26, 27, 28 i 29) and then on the vibrating screens 13 marked with (31, 32, 33 and 34) with Φ10 mm mesh, the +10 mm class is passed in the waiting bunkers (CC) (36, 37, 38 and 39), and the ore from the conical crusher (25) passes 15 on the vibrating sieve (30) with Φ3 mm mesh and the +3 mm class is recycled to the conical crusher (25), and the -3 mm class passes into the waiting hopper (35), characterized by the fact that the 17 ore crushed and sorted from the waiting bunkers passes into automatic dispensers (47, 48, 49, 50 and 51) with gravimetric system with weighing tape and subsequently are passed into a 19 dispenser trolley (52), from which is discharged into a sieve (53) which is placed on the platform of another stroller (54) and is guided under the crane hook (55) which supports the yoke with the two 21 hooks and is lifted by the yoke hooks and directed to the hopper (56) ) of granular ore feed of an oven (E), where the sulphide is burned of the kidney at temperatures of 23 750 ... 800 ° C, and from the limestone deposit (40), the limestone with the granulation between Φ 60 and Φ 80 mm is brought to the furnace (D) of burning the limestone, on conveyor belts, where with the help of a 25 skip ( 41), it is charged to the top of a furnace (42) which is heated with methane gas, at a temperature of 1250 ⁰ C, in the area of the burners, so that when the limestone 27 is lowered in the furnace it is dissociated, after which the burnt lime it is cooled and brought to the work hopper (43) where the burnt lime is passed through a jaw crusher (44) and from here it falls on a Vibrating sieve (45) with Φ 40 mm mesh, of which the +40 mm class is recycled to the jaw crushers (44), and the -40 mm class is passed into the waiting bunker (46), after which 31 gold processing takes place. and silver in the three-phase electric arc furnace, in which the desulfurized ore is brought to the form of briquettes, so that the fine grinder is not entrained by the gases 33 produced in the three-phase electric arc furnace for melting, the briquetting takes place using a binder and a hardener, without the need for drying, using a horizontal shaft mixer with the possibility of rotating in both directions and after loading the briquettes of the three-phase electric arc furnace, melts the load and obtains the melt, followed by the deoxidation of the bath, by 37 diffusion or precipitation, giving the bath a reducing mixture, the mixture is slagged several times, until the slag turns white, and a few minutes before unloading, 39 s it proceeds to deoxidize, precipitating, giving into the bath pieces of deoxidizers, and preparing the discharge in the pouring pot, pot that can be with stopper or with drawers that is 41 heated to at least 1250 ° C, and also , the casting assembly is also prepared, so that the normally conical ingot can be painted inside with dewatered tar and preheated to 43 at least 125 ° C, after casting the alloy, the plug or drawer of the pot closes the flow hole and the casting pot with the slag at the electric arc furnace it is directed to the cylindrical mixer 45, where the auxiliary hook of the crane is hung by the shaft at the bottom of the pot and the slag is discharged into the storage compartment, and after the solidification of the alloy, it is executed 47 RO 128995 Β1 stripping of the ingot, and after cooling the ingot, it is directed for the electrolytic refining of gold, silver and other accompanying metals and then the electrolyte is developed in the electric arc furnace, using fluxes such as: fluorine, quartzite , bauxite, magnesite and burnt lime, and after melting the materials, samples are taken for the chemical analysis of the electrolyte, after receiving the result, corrections are made, by the addition of materials and the bath temperature is measured with the immersion thermocouple Pt-Pt 10% Rh, and the casting temperature of the electrolyte must be at least 6O ... 7O ° C higher than the melting temperature of the electrolyte, followed by the discharge of the electrolyte into a casting pot, which is directed to the electrolysis tank where, by tilting the pouring pot, the electrolyte is discharged and the addition of slag in the electrolyte in the electrolysis tank will be at least 5%, following as by experimentation to determine the maximum value, and then the extraction of the metal from the electrolysis tank is carried out using the extraction pot with connection to the vacuum system and with inert anodes made of a weldable carbon steel block, obtained by forging or pouring from OT 40-1 containerized steel. Process according to claim 1, characterized in that the unloading of the alloy from the cathode to the base of the cathode glass in the electrolysis tank is made directly in a pouring pot, and the electrolysis tank has a longitudinal section inward of an inclination of 2 to 8 °. 3. Process according to claim 1, characterized in that the lining of the three-phase electric arc furnace is made with printed carbon mass and baked at a temperature of 1150 ± 10 ° C. An installation for carrying out the process according to claim 1, characterized in that it has automatic dispensers (47, 48, 49, 50 and 51) with a gravimetric system with a weighing tape in connection with a dispensing trolley (52) and with a sieve ( 53) which is placed on the platform of a trolley (54) and an oven (Eg, where the sulfur is burned from the ores, a mixer with a horizontal axis for making briquettes, and for the elaboration of gold and silver, a three-phase electric arc furnace is provided and a pot with a stopper or drawer, and a normally conical ingot and an electrolysis tank which is equipped with a vault formed by a number of sectors of movable and independent vaults that allow their lifting and turning in during the technological works carried out in the basin, the vault sectors are constructed of chromomagnetic-shaped refractory bricks and on the raised vault sectors mounted elements d It is sealed from steel sheet, welded, cooled with water circulation, and to the electrolysis tank, using precocious carbon anodes and inert anodes, in which precocious carbon anodes are encased in metal containers, comprising the lower, upper and lateral surfaces. , made from refractory alloys. 5. An installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Ti at least 5% and not more than 9%; Wcel at least 10% and at most 20%, and the base Nb. 6. An installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Zr at least 1% and not more than 3%; W at least 10% and not more than 14%; Your at least 25% and not more than 29%, and the base Nb. 7. The installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Ti at least 6% and not more than 10%; Mo at least 3% and not more than 5%; Zr at least 04% and not more than 08%; Wcel at least 4% and not more than 6%; At least 8% and not more than 18%, and base Nb. RO 128995 Β1 8. Installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Ti at least 6% and not more than 12%; Mo at least 5% and not more than 9%; Wcel 3 at least 16% and at most 22%, and the base Nb. 9. An installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Zr at least 0.5% and not more than 1.5%; W at least 8% and maximum 12%, and 7 base Ta. 10. The installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Ti at least 0.5% and not more than 1.6%; Zr at least 0.1% and not more than 0.5%, and 11 basis Mo, 11. The installation for carrying out the process according to claim 1, characterized in that the refractory alloys from which the anodes are made are chemical compositions expressed in mass percentages: Nb at least 0.2% and not more than 6%; Ta at least 2% and not more than 6%, and 15 W base, or of metallic plates in austenitic refractory rolled steel. 12. An installation for carrying out the process according to claim 1, characterized in that, for making an electrical contact in the hearth of the electrolysis tank between the longitudinal channel of the precoated carbon blocks and the cathode bar of steel, a printed and baked carbon mass 19 is used at 1150 ± 10 ° C.