RU2817274C1 - Device for pyrometallurgical processing of sulphide ores and concentrates - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of pyrometallurgical processing of ore raw materials of various material composition in a liquid-slag bath, in particular, to a device for continuous melting of sulphide materials. Device comprises a bath in which a gas-lift chamber with tuyeres, a melting chamber, a settling chamber and a light phase drain pocket are arranged in series and separated from each other by partitions, note here that said gas-lift chamber can be filled with matte melt to immerse tuyeres therein and to return matte melt to slag melt in smelting chamber.

EFFECT: increased degree of extraction of valuable components into matte and reduction of their content in slag.

7 cl, 1 dwg

Description

TECHNICAL FIELD

The invention relates to the field of pyrometallurgical processing of ore raw materials of various compositions in a liquid-slag bath, in particular, to a device for continuous smelting of sulfide materials.

BACKGROUND OF THE ART

There is a known method for continuous smelting of sulfide materials in a liquid bath, which consists of processing sulfide materials by bubbling oxidizing gases in a furnace consisting of a rectangular shaft, a caisson belt with tuyeres, a device for loading the charge, devices for releasing slag and matte (see USSR copyright certificate No. 813102, IPC F27B 3/00).

The disadvantage of this method is the melting of the charge due to the heat from the combustion of excess sulfur and, as a consequence, the production of waste gases with a high content of sulfur oxides and sublimates in the form of arsenic and antimony compounds, which significantly complicates and increases the cost of gas purification. In addition, in the known method it is almost impossible to obtain a metal phase due to overheating and possible release of the molten mass into the flue. The known method is ineffective for more complete separation of the matte phase from the slag.

There is a known method and device for continuous melting of sulfide materials in a gas lift mode in a liquid bath containing a gas lift with tuyeres organizing upward and downward flows of slag melt, a settling chamber communicating with the gas lift through the slag phase, devices for releasing slag and matte (RF Patent No. 2123651( 1, 3) class F27B 17/00, 1998).

A gas-lift furnace is more productive, but it does not solve the issues of reducing sulfur oxides from exhaust gases and mixing them with sublimates of arsenic compounds and other elements. In addition, the known method does not solve the problem of reducing the loss of matte with slag.

In addition, there is a known method and device (furnace) for processing sulfate-containing concentrates, including melting the charge to produce matte and slag melts, characterized in that the melting is carried out continuously in a circulating molten slag in an enclosed melting chamber with the release of the melting products into a settling chamber at the phase interface matte slag (RF Patent No. 2348713 С22В 11/02, F27B 17/00, 2009) (prototype). In the known method, due to the forward movement of superheated circulating slag and charge in the melting chamber down to the matte-slag phase boundary, sublimates from the melting of the charge are captured and carried into a special flue located in the settling chamber. In this case, separation of the working gases of the gas lift from the sublimates is achieved, which significantly reduces the concentration of sulfur dioxide in the exhaust gases. In this case, the furnace known from the prototype includes a gas lift with tuyeres immersed in the molten slag, gas separation and settling chambers, a gas duct for removing sublimates and low-boiling smelting products from the settling chamber, a melting chamber immersed in the settling chamber at the slag matte phase boundary.

However, in the method known from the prototype, when circulating slag, the load on the settling chamber increases, which leads to a decrease in the settling time of the slag and, accordingly, and the entrainment of matte containing valuable components with the spent slag. In addition, when the slag circulates during the melting of the charge, an emulsion of matte in the slag is formed, which, during delamination, involves the capture of the matte with the slag, which, together with a decrease in settling time, also contributes to an increase in the entrainment of the matte with the slag, thereby reducing the extraction of valuable components into the target product. In addition, the circulation of slag through the melting and then settling chambers increases the load on the settling chamber and, as a result, increases the capture of matte with slag.

DISCLOSURE OF INVENTION

The objective of the invention is to develop a device (furnace) that makes it possible to increase the extraction of valuable components into the matte, reduce the content of valuable components in the slag to waste values, expand the scope of application of the method, eliminate the circulation of slag through the melting chamber and organize the interaction of blast gases with sulfide sulfur during simultaneous melting charge and separation of sublimates and low-melting smelting products from blast gases.

The technical result achieved in this case is to increase the degree of extraction of valuable components into the matte and reduce their content in the slag.

The specified technical result is achieved due to the fact that the device for processing sulfide ores and concentrates contains a bath in which a gas-lift chamber with tuyeres, filled with molten matte, in which the tuyeres are immersed, a melting chamber, a settling chamber and a pocket, are located in series and separated from each other by partitions. draining the light phase, while the gas lift chamber is configured to return the matte melt to the slag melt in the melting chamber.

The settling chamber contains a gas separation chamber with a gas duct for removing sublimates and low-boiling smelting products.

Above the gas lift and melting chambers there is a gas separation chamber with a gas duct for removing gases from the gas lift chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clear from the description, which is not restrictive and is given with reference to the accompanying drawings, which show:

Fig. 1 - Design of the claimed device 1 - bath; 2 - gas lift chamber; 3 - melting chamber; 4 - settling chamber; 5 - gas duct of the gas separation chamber for removing gases from the gas lift chamber; 6 - gas duct of the gas separation chamber for removing sublimates from the settling chamber; 7 - polarized electrodes; 8 - slag drain fitting; 9 - siphon for draining matte; 10 - siphon for draining the metal phase; 11 - loading channel; 12 - blowing tuyeres; 13 - partition for separating the melting chamber; 14 - baffle partition; 15 - channel for removing the gas phase from the light phase drain pocket; 16 - partition forming a pocket for draining the light phase; 17 - partition separating the gas lift and melting chambers; 18 - light phase drain pocket; 19 - gas separation chamber located above the gas lift and melting chambers; 20 - gas separation chamber located above the settling chamber.

IMPLEMENTATION OF THE INVENTION

The method of pyrometallurgical processing of sulfide ores and concentrates involves melting the charge in a slag melt in an enclosed melting chamber to produce matte and slag melts, while the melting of the charge to produce matte and slag is carried out with the continuous return of the matte melt to the molten slag.

To return the matte melt, a flow of neutral or reaction blast gases is used.

A device for processing sulfide ores and concentrates contains a bath (1), in which a gas lift chamber (2) with tuyeres (12) is sequentially located and separated from each other by partitions (13, 15), filled with molten matte, into which the tuyeres (12) are immersed. , a melting chamber (3), a settling chamber (4) and a light phase drain pocket, while the gas lift chamber (2) is configured to return the matte melt to the slag melt in the melting chamber (3).

In the settling chamber (4) there is a gas separation chamber with a gas duct (6) for removing sublimates and low-boiling smelting products.

Above the gas lift (2) and melting (3) chambers there is a gas separation chamber with a gas duct (5) to remove gases from the gas lift chamber (2).

Polarized electrodes (8) are installed in the settling chamber (4).

In the partition (16), which forms the light phase drain pocket, there is a channel (15) for removing the gas phase from the light phase drain pocket.

In the side wall of the bath (1), in the area of the melting chamber (3), above the slag layer, there is a loading channel (11).

A partition (14) is made in the gas duct (5) to remove gases from the gas lift chamber (2).

In the end wall of the bath (1), located in the area of the gas lift chamber (2), there is a siphon (10) for draining the metal phase, and in the end wall of the bath (1), located in the area of the light phase drain pocket, there is a fitting (8) for draining slag and a siphon (9) for draining the matte.

Pyrometallurgical processing of sulfide ores and concentrates using the claimed device is carried out as follows.

After heating the furnace, the required amount of metal phase is poured into the melting chamber (3) through the loading channel (11), then the matte melt and then the slag melt. The volume of metal phase, matte melt and slag melt is calculated from design solutions in order to create a volumetric ratio of matte melt to slag melt of at least 3:1. During the period of filling the furnace with molten slag, neutral blast gases are supplied through tuyeres (12) immersed in the matte melt into the gas lift chamber (2). In this case, a controlled circulation of the matte melt begins between the settling chamber, then the gas-lift chamber (2) and the melting chamber (3), located between the partition separating the gas-lift chamber (2) and the melting chamber (3), and the partition (13) separating the melting chamber ( 3) and a settling chamber (4), as a result, the matte melt is returned to the slag melt in the melting chamber. The final heating of the furnace to operating temperatures and then maintaining the temperature parameters of the furnace operation is carried out without loading the charge by applying voltage to polarized electrodes (7), which are fixed in the upper wall of the bath (1) and immersed in the molten slag. After heating the entire furnace masonry and the matte melt to the required temperature, they begin to load the main mass of the charge (sulfide concentrate with fluxing additives) through the loading channel (11) into the melting chamber 3. The volume of the dosed charge is determined by calculating the excess amount of heat brought by the circulating matte into the melting room chamber (3), necessary for melting the charge, decomposing higher sulfides and distilling sublimates while maintaining the liquid slag bath. When neutral blast gases are supplied using tuyeres (12), a foam-liquid phase is formed into the matte melt layer, which, due to the generated flow of neutral blast gases from the gas lift chamber (2), enters the gas separation chamber located above the gas lift (2) and melting (3) chambers , where the foam-liquid phase separates into gaseous and liquid phases. The gaseous phase through the gas duct (5) to remove gases from the gas lift chamber (2) is removed from the furnace for gas cleaning, and the liquid phase enters the molten slag layer in the melting chamber (3). In the process of melting sulfide materials in the melting chamber (3), decomposition of higher sulfides occurs with the formation of elemental sulfur and gas formation of sublimated and low-melting components, which are carried away by the flow of molten matte circulating along the length of the furnace into the settling chamber (4) and are then removed from the furnace through the gas duct (6 ) to remove sublimates from the gas separation chamber located above the settling chamber (4). The slag phase clarified in the settling chamber (4) is directed into the light phase drain pocket formed by the partition (16), separating the said pocket and the settling chamber (4), and is then drained through the slag drain fitting (8). The partition (16) has a channel (15) for removing the gas phase from the light fraction drain pocket. The metal phase formed in the technological process is removed from the furnace through a siphon (10) to drain the metal phase. Excessive amount of matte melt is removed from the furnace through a siphon (9) to drain the matte.

The mixture of matte-slag liquid and liquid emulsion of slag in the matte obtained as a result of melting the charge in the melting chamber (3) and the decomposition of higher sulfides is stratified due to the difference in densities and the mutual immiscibility of the matte and slag into slag and matte (sulfide) phases in the settling chamber (4) . In this case, due to the formation of a slag emulsion in the matte, a clarified slag phase is formed without including the matte phase. The capture of slag by the matte does not affect the quality of the matte, since its slag component is returned to the technological process with the circulating matte, therefore, the degree of extraction of valuable components into the matte increases and their content in the slag decreases. In addition, eliminating slag recirculation reduces the load on the settling chamber and thereby increases the settling time of the slag phase, which also contributes, like the processes described above, to reducing the yield of valuable components into waste products and increasing their yield into target products.

A fundamentally new design of the technological process and equipment in the proposed method of implementation dictates new approaches to the processing of sulfide concentrates:

- processing of sulfide concentrates can be carried out with partial release of elemental sulfur during thermal decomposition of higher sulfides during smelting using neutral or oxidizing gases with a controlled oxidizing agent content;

- during the smelting process during heat treatment, it is possible to remove environmentally hazardous elements (arsenic, antimony, etc.) from the smelting products;

- carrying out the operation of obtaining and converting matte in one technological apparatus in a continuous mode to obtain, for example, blister copper;

- variation of technological tasks when transporting matte by gas lift when using blast gases of various compositions;

- introduction of additional charging additives when processing matte with blown gases;

- involvement of oxidized sulfide products in the process.

Until now, when processing sulfide raw materials, there is an urgent task of sharply reducing sulfur dioxide emissions into the atmosphere. In this case, the best solution to this problem is to eliminate the formation of sulfur dioxide (or significantly reduce its amount) in the technological process. The most attractive process for reducing the formation of sulfur dioxide is to carry out the conversion process with oxygen deficiency. In this case, the reaction 2FeS+O2=2FeO+2S is possible. When using the above-described matte processing processes, a shift in the equilibrium of this reaction towards the formation of elemental sulfur can be facilitated by the organization of almost any ratio of iron sulfide and oxygen by varying both the volumetric gas-liquid ratio in the gas-liquid mixture and the composition of the blast gases in the gas-lift chamber. Another possible way to reduce the formation of sulfur dioxide in exhaust gases is to introduce calcium dioxide as a fluxing additive. In this case, the organization of the gas lift process should be carried out using neutral transport gas. In this case, the reaction FeS+CaO=FeO+CaS occurs. Calcium sulfide is soluble in slag and is removed along with it from the technological process.

This is also achieved due to the formation of a slag in matte emulsion as a result of melting, which, when separated, gives a pure slag phase (without including the matte phase), and an increase in the settling time of the slag phase.

The technical result is achieved due to the fact that when the gas lift chamber is immersed in the matte melt, the blast gases interact with sulfide sulfur with simultaneous recycling of the matte through the melting chamber.

Melting in a furnace is carried out by treating the charge with a superheated matte melt to form a slag-in-matte emulsion, which, when separated, forms a “pure” slag phase without the inclusion of matte.

Below are the data confirming the achievement of the technical result: At a temperature in the furnace of 1600°C, 6 kg of a mixture of refractory sulfide-arsenic with the addition of sulfur-containing copper concentrates together with oxidized copper-containing waste from concentration factories of concentrates was melted, composition, %: iron - 19.48; sulfur - 21.5; arsenic - 3.88; lead - 0.13; zinc - 0.35; copper - 22.4; aluminum oxide - 9.6; silicon oxide - 30.13; calcium oxide - 2.37; potassium and sodium oxides - 0.89; others - 12.55; gold - 67.33 g/t with the addition of 20% limestone to the concentrate. The composition of the resulting matte was determined by the concentration of sulfide sulfur in the charge. The volume of circulating matte was determined by creating a matte-slag ratio in the gas-lift and smelting zones of at least 3:1. Both shein and the resulting metallic copper were used as a co-precipitant for gold and arsenic. The slag yield from the charge was 60.87%. Slag composition,%: silicon oxide - 48.8; calcium oxide - 28.4%; magnesium oxide - 2.6; aluminum oxide - 14.2%; sodium and potassium oxides - 4.0%; arsenic - 0.2%; sulfur - <0.1; gold - 0.1 g/t. The yield of matte from the charge was 21.9%. Composition of dump matte, %; iron - 57.7; arsenic - 0.2%; copper - 0.06; zinc - 0.15; lead - 0.6; sulfur 22.3; other 17.4; gold - 0.05 g/t. The yield of metallic copper, kg - 1.35 with a gold content of 300 g/t. From what is disclosed above, it follows that during the smelting process according to the proposed method in the claimed device, waste slag and matte with a low content of copper and gold are obtained.

Claims (7)

1. A device for processing sulfide ores and concentrates, containing a bath in which a gas lift chamber with tuyeres, a melting chamber, a settling chamber and a light phase drain pocket are successively located and separated from each other by partitions, wherein the gas lift chamber is configured to be filled with melted matte with immersion of tuyeres into it and with the possibility of returning the matte melt to the molten slag in the melting chamber. 2. The device according to claim 1, characterized in that in the settling chamber there is a gas separation chamber with a gas duct for removing sublimates and low-boiling smelting products, and above the gas lift and melting chambers there is a gas separation chamber with a gas duct for removing gases from the gas lift chamber. 3. The device according to claim 1, characterized in that polarized electrodes are installed in the settling chamber. 4. The device according to claim 1, characterized in that in the partition forming the light phase drain pocket, there is a channel for removing the gas phase from the light phase drain pocket. 5. The device according to claim 1, characterized in that a loading channel is made in the side wall of the bath, in the area of the melting chamber, above the slag layer. 6. The device according to claim 2, characterized in that a partition is made in the gas duct to remove gases from the gas lift chamber. 7. The device according to claim 1, characterized in that in the end wall of the bath, located in the area of the gas lift chamber, there is a siphon for draining the metal phase, and in the end wall of the bath, located in the area of the light phase drain pocket, there is a slag drain fitting and a siphon for plum matte.