BG1618U1 - TECHNOLOGICAL LINE FOR PRODUCTION OF LEAD AND LEADS - Google Patents

Abstract

The useful method refers to a process line for lead and lead alloys production from a wide range of raw materials and scrap in various ratios. The line as per the present model includes in-line a processing unit (1) to collect and store lead containing and slag material linked through conveying belts to a batch preparation hopper (2). The system (2) is connected by a feeding device to a furnace (3) which is connected also to a hard reductor feeding system for reducing lead slag and operating in two repeating modes for oxidation melting and slag reducing. The top of the furnace (3) is connected to a utilizing tank with a radiation surface (9) to cool gases, to partially precipitate dust and cake and to utilize heat as steam. The furnace is connected also by a flue to a wet scrubbing system (10) to fully scrub gases from dust down to 1 mg/nm3. The wet scrubbing system (10) is linked to a sulphuric acid installation (11) to scrub sulphur dioxide, and installation (11) is connected to a flue gas scrubber (12) for additional fine scrubbing of sulphur gases containing sulphur dioxide in concentrations less than 400 mg/nm3 and it is connected to a stack to exhaust them in the atmosphere. The lead bullion outlet at the bottom of the furnace (3) is connected by a furrow to a casting installation to cast lead bullion into blocks of 4-5 t. The casting installation is connected by conveyors to a system of refining kettles (4,4a) to consequently remove copper, tellurium, arsenic and antimony, silver, zinc, bismuth, calcium and magnesium and producing a 99,99% pure lead free from impurities. Kettles are linked by a pump and a furrow to a casting installation (5) ingot casting or alloying to a specific alloy. The outlet for slag tapping during the second mode of operation of the furnace (3) is connected by a granulating furrow to block (6) for additional refining of lead slag to less than 0,2% lead content and less than 2% zinc content in the residual slag. It is also connected

Description

(54) TECHNOLOGICAL LINE FOR MANUFACTURE OF LEAD AND LEAD ALLOYS

Technical field

The utility model refers to a technological line for the production of lead and lead alloys from a wide range of primary and secondary raw materials in different ratios.

BACKGROUND OF THE INVENTION

In general, there are two types of technological lines - the first for pyrometallurgical production of lead and lead alloys and the second type - for hydrometallurgical production.

Both types of technological lines known in the art have many drawbacks in current technical, economic and environmental requirements. More important disadvantages of the first type of technological lines are the limited possibilities for processing of primary and secondary raw materials, processing of large quantities of inert masses, high energy consumption (coke, air, natural gas, electricity), difficult technological and economically unprofitable use of sulfur. , inability to comply with standard levels of environmental protection and adverse working conditions.

The second type of technological lines pose a great danger to the working and the environment due to the work with highly aggressive reagents.

Known for the preparation of lead (PCT / AU2006 / 001460), which includes a technological unit for the preparation of a mixture of lead concentrate, fluxes and solid fuel and power supply, through which the prepared charge is fed into an ISASMELT melting furnace or other. n. "The lance is a submerged peak." In the known apparatus, the air or oxygen is fed into the furnace bath through this lance, the resulting black lead and lead-containing slag are drawn through the corresponding openings (or overflows), the slag extracted from the melting furnace is solidified and shaped into ingots together, which together with coke and fluxes are fed into a shaft furnace for smelting and receiving black lead for refining. From the shaft furnace, black lead and slag are drawn through the corresponding openings. The disadvantage of this production line is the production after the reduction stage of the slag with high lead content of 40-55 wt. % and the need for additional cooling and briquetting of the slag with subsequent reduction of the slag in the shaft furnace.

The technical nature of the utility model

The task of the utility model is to create an efficient, environmentally friendly and maximally wasteful technological line for the production of lead and lead alloys, which allows the processing of a wide range of primary and secondary raw materials; a high degree of purification of dust gases that are processed as a turnover in the main metallurgical unit; high degree of purification of sulfur dioxide gas and production of sulfuric acid; production of slag suitable for raw material in the economy (cement, ceramic, road construction, landslide reinforcement, etc.), production of products suitable for processing in other spheres of economy; high quality of working environment and working conditions.

The utility model refers to a technological line for the production of lead and lead alloys, which includes sequentially linked technological units, systems and aggregates that ensure the flow of processes: preparation of raw materials (lead and secondary, slag-forming materials, fuels, etc.). and preparing the charge, melting the charge, separating the products of melting and further treating them by refining the black lead, depleting the slag, recovering heat from the exhaust gases and cleaning and m.

According to the current utility model, the Raw Materials Warehouse (1) focuses on the collection of a variety of raw materials - primary concentrates and secondary - paste from accumulators, lead oxide powders, lead pads from precipitation and purification of solutions and water, and other non-primary raw materials containing lead in compounds or non-compacted metal form. In the warehouse are stored slag-forming components in oxide form, containing calcium, silicon, iron, as well as a solid reducer with suitable particle size.

Materials from process unit (1) are subjected to processing and blending into process unit (2) according to a preset program1618 frame for optimum slag formation. The charge thus prepared through a feeder enters a melting furnace with the so-called "lance (tube) with submerged tip" (3), where energy carriers are injected into the liquid bath - to intensify and regulate the processes - fuel and air enriched with 93- 95% oxygen, coal, and the submitted charge is subjected to periodic two-stage processing - melting of the charge and reduction of slag, after the first stage the lead is partially separated in metallic form and drained, and for the second phase in the furnace a solid reducer and after the process is completed separately and sharpen metal and slag.

The black lead drained from the melting furnace (3) is poured into blocks and fed for refining to the process unit (4), or in the other arrangement of the units the lead from the furnace (3) can be fed in liquid state for high temperature refining to the process unit unit (4a), whereby separate refining processes are carried out, the final product - lead is poured and the intermediate products obtained during refining are processed to produce commodities containing Cu, Ag, Bi, They and others.

The Alloys Technology Unit (5) has organized processes for alloying refined lead to a commodity product - an alloy with the desired composition.

The dust gases after the melting unit (3) are directed to the boiler (9), where partial precipitation of the circulating materials (powders, cake) takes place and their heat is recovered to produce steam. The gases are transferred to a wet scrubber system (10), in which a complete purification of the dust gases up to 1 mg / nm ³ occurs. The purified gases enter an installation (11) for sulfuric acid H ₂ SO ₄ , in which SO ₂ is transformed into H, SO ₄ , and then passed into a tail gas scrubber (12) for fine purification of sulfur gases by trapping them in the form of a product suitable for processing in other areas of the economy - gypsum, zinc or sodium sulfate. This ensures that the exhaust gases contain less than 400 mg / nm ^{3 of} sulfur dioxide.

The recycled materials caught in the boiler (9) and the wet cleaning system (10) are returned for reprocessing to the technological unit (1).

The slag from the melting of the raw material (charge) is processed into a Fuming furnace (6). There are two options - feed into the Fuming furnace (6) of the liquid slag or pre-solidify it and then feed into the furnace (6). A fuel-air mixture is blown into the liquid bath to oxidize and evaporate the lead, zinc, cadmium and rare metals present in the slag.

After the expulsion of the zinc and lead in the gases in the form of oxide powders is completed, the slag containing less than 0.2% lead and less than 2% zinc is drained. The hot gases and powders pass through the boiler (7) for coarse dust removal and heat removal to produce steam. The cooled and partially dusted gases undergo further fine-tuning in a dust collection system (8) to a dust content of about 5 mg / nm ³ . The captured powders from the boiler (7) and the dust collection system (8) are rich in lead, zinc and rare metals and are fed for their extraction in other technological schemes.

In each technological unit of the technological line, according to the present utility model, the capture and dusting of all the gases from the facilities is organized through suitable dust collecting facilities - independently organized for a separate unit or common for the technological unit.

Advantages of the technological line according to the utility model are:

- the ability to handle a wide range of primary and secondary raw materials in different proportions;

- energy-efficient use of the potential of the raw material and the added fuel (natural gas), oxygen;

- consumption of solid fuel only for the reduction of the oxide phases of lead and zinc in the slag;

-Energy-efficient use of the heat of gases from metallurgical furnaces for steam production;

- a high degree of purification of gases from dusts that are processed as a turnover in the main metallurgical unit;

- high degree of purification of sulfur dioxide gases and production of sulfuric acid;

- practically no waste, slag is suitable for raw material in the cement industry, construction, forestry;

- the complexity of the facilities and the possibility of implementing program management;

- high quality of working environment and working conditions.

The utility model is illustrated by the attached figures.

Short description of the figures

Figure 1 is a technological line for the production of lead and lead alloys;

2 is a flowchart to illustrate an exemplary embodiment.

Exemplary implementation of the utility model

In a preferred embodiment, at the beginning of the production line is a raw material warehouse (1), where the raw materials for the production of lead and lead alloys are received and stored. They are primary - lead concentrates; secondary sulphate paste from cushioned batteries, lead kettles; revolutions - oxides and sludges from the refining process, lead powders; fluxes - quartz, lime, etc.

With the help of a crane, the materials from the warehouse (1) are fed to feed hoppers, the outputs of which are fitted with disc feeders for feed via a collecting conveyor on the vibrating screen for grading the processed materials. With conveyor belts, the materials are discharged into the batch preparation system (2), including daily bins, each for a different material. Below each hopper is mounted a belt dispenser for unloading the material on a collector conveyor connected to a mixing drum - granulator for homogenization of raw materials. Thus, the hopper type batching system (2) is more flexible and subject to a high degree of automation.

Separately, there is a coal feed system consisting of a connected hopper, a bucket elevator and a daily hopper with a belt dispenser mounted above the conveyor.

The melter unit (3) operates in a periodic mode - oxidative melting and reduction. During the first stage, the furnace (3) feeds the charge from system (2) and the energy carriers are injected through the lance, periodically draining black lead and accumulating lead-rich slag. After a certain amount of slag has accumulated, a reduction process begins, in which a solid reducer, such as coal, is fed into the furnace. The resulting black lead is periodically drained from the furnace and the slag is drained at the end of the operation for further processing.

The black lead from the two stages of the melting furnace (3) is discharged into the foundry machine and molded into blocks of 4-5 t, which are transported to a system of refining boilers (4), each with a capacity of 250-300 t, where copper, tellurium, arsenic and antimony, silver, zinc, bismuth, calcium and magnesium are refined. The resulting 99.99% purity lead is cast on a standard block 45 kg casting machine or alloyed. Some of the materials obtained as a result of refining are processed to Dore alloy, bismuth lead, tellurium, matine and peice, and the other part is returned as circulating material to the processing unit (1).

The 99.99% lead obtained is traded directly or alloyed in the Lead Alloys technological unit (5) to the desired composition.

The other products obtained during refining are processed as follows: copper slag - in a short-kiln oven until a copper mat and mold are obtained; tellurium strands - to tellurium; silver foam - in a liquid boiler, a distillation furnace and a bell furnace next to the Dore alloy; rich bismuth dross - by enrichment in a refining boiler to rich bismuth lead, oxides and sludges in metal-containing circulating materials, fed at the beginning of the process as part of the charge.

The slag of the melting unit (3) is subjected to granulation by means of a sequentially connected chute granulator, pool and dewatering hopper and then stored in a receiving hopper and fed through conveyors to a Fuming furnace (6) operating in batch mode to further extract zinc and lead from slag. In the furnace (6), with the help of a blown fuel-air mixture, the granular slag is first melted and then the zinc oxides and lead oxides are reduced to the corresponding metals and evaporated. Upon completion of the process, the waste slag containing <0.2% lead and <2% zinc is introduced into the granulation pool via a granule granulator and granulated to a finished commercial product.

Process fumes from the Fuming furnace (6), which carry the zinc and lead vapor through a gas duct, are cooled in a boiler (7) where their oxidation occurs, the condensation of the zinc oxides and the lead and primary (coarse) separating them from the gas stream in the form of dusts, then passing through a dust collection system (8) consisting of coolers for the coarse dusting of the gases and a bag filter for trapping the fuming oxides, and the purified gas being sent through a chimney into the atmosphere .

The powders from the boiler (7) and the dust collection system (8), due to their still high zinc and lead content, are diverted to other technological circuits and the heat from the gases from the boiler (7) is utilized to produce steam. .

The process gases from the melting furnace (3) at a temperature of 1000-1400 ° C are cooled to about 700 ° C in a heat recovery boiler (9) using the extracted heat used to produce steam.

After conditioning in the boiler (9), the gases enter the wet cleaning system (10). The cleaning system consists of a sequentially connected adiabatic cooling tower, a radial scrubber, a cooling tower with a filling and wet electrostatic precipitators. It is purified from dust to values <1 mg / nm and gas cooled to 40-45 ° C. The cleaning product is filtered into a filter press and sent to the warehouse / 1 /.

The finely purified and cooled gases from the process unit (10), through a connected thickener, reservoir, circulation pump and pipeline, are treated for sulfur dioxide treatment in the wet sulfuric acid H ₂ SO _{4 system} (11). In the system, the gases in heat exchangers are heated to about 400-450 ° C, the conversion of sulfur dioxide SO ₂ to sulfur trioxide SO, and the condensation of the water vapor and SO ₃ to give 96% sulfuric acid H ₂ SO ₄ as a commercial product.

The SO ₂ purified gas is further purified from unreacted sulfur dioxide in a tail gas scrubber (12), where sulfur dioxide is purified by means of a scrubbing reagent in the form of sulfate - gypsum or zinc sulfate depending on the type of reagent.

The exhaust gases from unit (12) contain less than 400 mg / nm ^{3 of} sulfur dioxide and are emitted through a chimney into the atmosphere.

Claims (12)

Claims A technological line for the production of lead and lead alloys, characterized in that it consistently includes: a technological unit (1) for the collection and storage of lead and slag-forming raw materials and materials, connected via conveyor belts with a bunkering system ( 2) connected by means of a feeder with a melting unit (3), simultaneously connected to a feeder system for a rigid reducer, eg coal, for the reduction of lead slag and operating in two periodically repeated modes for the oxides, respectively. fusion of the charge and reduction of the slag connected at the top with a heat recovery boiler with a radiation part (9) to cool the gases, partially precipitate the circulating materials - dust and cake and recycle their heat as a steam connected to a gas line with wet cleaning system (10) for the complete purification of dust gases up to 1 mg / nm ³ connected to a sulfuric acid installation (11) for sulfur dioxide treatment coupled to a tail gas scrubber (12) for further fine cleaning of sulfur gases containing sulfur dioxide below 400 mg / nm ³ bound to a vent chimney in the atmosphere, and at the bottom of the melting unit (3), the black lead through the chute is connected to a casting machine to produce black lead blocks weighing 4-5 t, connected by conveyors to a refinery boiler system (4, 4a) for the sequential refining of copper, tellurium, arsenic and antimony, silver, zinc, bismuth, calcium and magnesium and obtaining lead purified from impurities up to 99.99% by pump and chute 1618 W for dispensing to a ready-made commercial product or fusion in a process unit (5) to an alloy of the desired composition, and the slag drain opening from the second mode of the submersible unit (3) is connected via a granulator granulator to a process unit (6) for additional extraction from the slag to a content in the waste slag of lead below 0.2% and of zinc less than 2%, connected to a waste gas boiler for the coarse dusting of gases and utilizing their heat (7) as steam, connected by a gas duct to a dust collection system ( 8) for additional fine-tuning to the contents of pax about 5 mg / nm ^3. Process line according to claim 1, characterized in that the process unit (1) consists of hopper-fed hoppers, at the exits to which disc feeders are mounted, which are connected via a collector conveyor to the vibrating screen for classification of the processed materials. . Process line according to claim 1, characterized in that the bunkering system of the hopper type (2) consists of daily hoppers with belt dispensers connected by conveyors with a mixing drum - granulator for homogenization of the materials. Process line according to claim 3, characterized in that the rigid gear feed system comprises a series-connected receiving hopper, a bucket elevator and a daily hopper with a belt dispenser mounted above the conveyor. Process line according to claim 1, characterized in that the wet cleaning system (10) consists of a series-connected adiabatic cooling tower, a radial scrubber, a filling cooling tower and wet electrostatic precipitators operating in a series of gas cleaning systems. Process line according to claim 5, characterized in that the adiabatic expansion tower and the radial scrubber are connected to a thickener whose overflow for the clarified solution through a tank, circulation pump and pipeline is connected to the beginning of the wet cleaning system (10). , and the lower orifice of the thickener is connected to a filter press by means of a separate sludge tank, which is connected by means of vehicles to a glass for circulating materials (1) for removal and storage of the spent product - cake. Process line according to claim 1, characterized in that the sulfuric acid installation (11) includes heat exchangers for preheating the exhaust gas to about 450 ° C, the outputs of which are connected in series with the exhaust gas to about 450 ° C, the outputs of which are connected in series with a contact apparatus for the conversion of sulfur dioxide to sulfur trioxide and a condenser column for condensing the sulfur trioxide vapor and water to give 96% sulfuric acid. Process line according to claim 1, characterized in that the copper slurries obtained in the technological unit (4, 4a) are processed in a short-drum furnace to obtain a matte and a mold. Process line according to claim 1, characterized in that the tellurium strands obtained in process unit (4, 4a) are processed into process unit (5) to tellurium. Process line according to claim 1, characterized in that the bismuth strands obtained in the technological unit (4, 4a) are enriched in a refining boiler to rich bismuth lead. Process line according to claim 1, characterized in that the process unit (4,4a) includes a boiler, a distillation furnace and a furnace for processing the silver foam obtained from the refining process into a Dore alloy. Process line according to claim 1, characterized in that the process unit (6) includes a conveyor-connected pool, a dewatering hopper, a warehouse, a receiving hopper mounted above a day hopper with a tape dispenser connected via a Fuming furnace gate lock, the opening of which is connected by means of a granulator basin to a granulation basin for the production of slag as a commercial product. fuming oxides connected to a gas outlet chimney and pneumotransport to remove the fuming oxides for further treatment.