MX2008002934A - Method for reprocessing lead-containing materials. - Google Patents

Abstract

The invention relates to non-ferrous metallurgy, in particular to methods for reprocessing lead-containing materials. The aim of the invention is to increase a lead extraction into a crude metal, to improve a specific performance and to simultaneously reduce the unit costs of energy vectors. The inventive method consists in preparing and drying a mix material, in carrying out roast melting in a suspended state in oxygen atmosphere in such a way that an oxide melt and mixtures of dusts with roast smelting gases are obtained, in reducing the melt during the filtration thereof through a layer of hot parts of a carbon reducing medium in such a way that a pure metal lead, a zinc-containing oxide melt and gases are obtained. The mix material is ground and classified and the separated fraction of dry mix material, 90% of the mass of which consists of particles having size of 0.01-0.10 mm, is supplied at the roast smelting stage. The moisture content of the mix material, during the preparation thereof, is equal to 8-16 % and a coal, in the dry mass of which a total carbon content ranges from about 49 to about 80% and a volatile content from about 11 to about 27%, is used in the form of a ground carbon reducing medium.

Description

PROCEDURE FOR PROCESSING MATERIALS CONTAINING LEAD Field of Invention The invention relates to non-ferrous metallurgical, mainly to processes for processing materials containing lead, of different origin. There is an extensive group of materials with lead content such as residues from hydrometallurgical processes, conversion of "mattes" ("clods") of copper, neutralization pulps and solutions of purification processes, which are not processed or processed in volume insufficient by well-known methods, so they accumulate in landfills. In addition to lead, these materials contain considerable amounts of zinc and copper, which reduces the recovery, the complexing of non-ferrous metals from the raw material of the ore, in their metallurgical processing processes. Simultaneously the storage of materials with lead content causes complicated ecological problems. Thus, the extension range of material processing with lead content represents a real task for technology and protection of the environment.

BACKGROUND OF THE INVENTION The process for processing lead-containing materials with increased sulphates and oxides content, such as lead residues, powders, battery paste and others, in the mixture of finely-grained lead concentrates, recycling, is known. powders, fluxes, coal dust - QSL-technology, based on the principle of melting by bubbling (Mager, K., Shulte, A. "Production and Technological Aspects of the First Four QSL-plants." Proceedings of International Symposium on processing of primary and secondary lead, Halifax, Nova Scotia, Canada, August 20-24, 1989, Pergamon Press Publisher, New York, pages 15-26). The procedure resides in the fact that the indicated mixture is granulated and the resulting wet grains are fed to the surface of the oxide melt containing from 35 to 60% lead, in the form of oxides. This molten oxide and the metallic lead layer below it are blown through a gas containing oxygen. As a result of the interaction between the sulphides of the raw material with the oxides of lead, at a temperature of 850-950 ° C, metallic lead is formed that is partially transferred to the molten oxide, as a result of its oxidation by using gas containing oxygen. By controlling the feeding of the grains and the consumption of oxygen-containing gas, a high constant concentration of lead oxides in the slag is achieved and the rate of metallic lead formation is predominant over its oxidation rate when using oxygen-containing gas. The resulting molten oxide, with a temperature no higher than 950 ° C, goes continuously to the reduction area, where as the slag goes towards the outlet, the melting temperature gradually increases up to 1150-1250 ° C, at the expense of the gas heater. Simultaneously with this, the reduction of lead oxides to metallic lead is carried out by blowing the melt with a mixture of air and pulverized or gaseous carbon material (coal, natural gas and others). The disadvantage of the known method is its low direct recovery of lead in metallic lead, the low specific capacity of the process and simultaneously the high specific consumption of energy vehicles (gas containing oxygen, carbon materials). This is caused by the fact that the reduction of the lead concentration in the molten oxide leads to the need to increase the temperature of this casting, during the oxidation and reduction stages of the process and, correspondingly, to the increase of the lead output in foundry powders (up to 50% and more of its mass in the load). During the processing of materials with lead content, with lead concentrations below 30% and iron oxidation rate greater than 50-60%, the melting process is almost destroyed due to the formation of viscous molten oxide, not applicable for blown with gas. Also known is the process for processing materials with lead content, with an increased portion of sulfates and oxides such as lead residues, powders, battery paste and others in the concentrate mixture. of lead sulfur, recycled powders, fluxes, coal dust - Ausmelt technology, based on bubbling smelting principie (Mounsey EN, Piret NL "A review of Ausmelt technology for lead smelting." Proceedings of the Lead-Zinc 2000 Symposium, Pittsburgh, USA, October 22-25, 2000, pp. 149-169). The method resides in the fact that said well-averaged mixture in the form of fine grains or granules, formed with a lead concentration of 25-60%, is fed to the surface of the molten oxide. Above, oxygen-containing gas is blown into the volume of the molten oxide and, due to the deficit of the process's heat balance, pulverized, liquid and gaseous coal fuel is also blown. As a result of the interaction between the sulfides of the raw material with the oxides of lead, at the temperature of 1000-1100 ° C, metallic lead is formed which is partially transferred to the molten oxide as a result of its oxidation, using oxygen-containing gas . Due to the control of the feed of the load and the consumption of the oxygen-containing gas, a high constant concentration of lead oxides in the slag is obtained and by the predominance of the rate of metallic lead formation over its oxidation rate, using gas which contains oxygen. The resulting molten oxide, with a temperature not exceeding 1100 ° C, is transferred to the process reduction stage, in continuous or intermittent mode or is trapped and granulated for further processing of solid lead slag in the reduction stage, with production of metallic lead. The reduction of the oxides of lead to metallic lead, from the lead-rich slag of the oxidation stage of the process, is carried out by blowing the smelter with a mixture of air and pulverized, liquid or gaseous carbon material (coal, petroleum , natural gas and others). The significant increase in the consumption of energy vehicles, with the concomitant increase in the temperature of the molten oxide, allows this process to be transferred from the mode of casting of metallic lead to the mode of lead (and partially of zinc) which smokes in foundry powders; which can then be processed, separately by this same procedure, with production of metallic lead. The disadvantages of the well-known procedure are low recovery of lead in metallic lead, low specific capacity of the process and, simultaneously, high consumption of energy vehicles (gas containing oxygen, carbon materials). The closest technical substance is in the process for processing lead-containing materials, such as lead and zinc residues, powder conversion, hydrolytic purification pulps of processing solutions containing mainly simple sulfates or compounds and metal oxides, including sulphates thermally stable (lead, calcium) and higher iron oxides (Patent RK # 9, C 22 B 13/02, 1997). According to this procedure, the preparation of a wet load is made from primary materials containing lead and fluxes, with introduction in them as a reducer for the pulverized sulphide material, up to a mass ratio of total amounts of sulfur, sulfur elemental and pyrite, to the total sulfur content in the filler from 0.08 to 0.87 and / or pulverized coal material at a rate of 4 to 12 kg of pure carbon per 100 kg of ferric iron and from 20 to 140 kg of pure carbon per 100 kg of sulphate sulfur. Therefore, the pulverized coal material is introduced, in which the activation energy of the coal gasification reaction is in the range of 56-209 kJ / mol. Concentrated lead sulphide or lead ore (polymetallic) is used as pulverized coal material. The wet load produced with a recommended moisture content of 2 to 16%, is dried until the residual moisture content is less than 1%. The dry charge is transferred to a roasting-melting stage, in the suspended state in an oxygen-containing gas atmosphere, with dispersed molten oxide production and the mixture of roasting-toasting powders and gases. The dispersed molten oxide, produced in the roasting-melting stage, is reduced by filtering it through the layer of heated particles of ground carbon material (coke or coal), with a grain size of 2-50 mm, with production of metallic lead, slag with zinc content depleted by lead and gases that mix with roasting-smelting gases. The powders are separated from the reaction gas mixture and returned to the roasting-melting stage.

In the stage of preparation of the wet load, under conditions of careful mixing of the materials containing natural binder compounds (soluble salts, hydroxides of metals and hydrates, gypsum) and in the presence of free moisture in the load, which is not less than 2%, its structuring occurs with the formation of "complex" micro-conglomerates from non-homogeneous particles, including both oxidized components (sulfates and metal oxides) and reagents-reducers (sulphides of metals and coal). Links are formed between the non-homogeneous particles in micro-conglomerates, in the preparation stage of the wet load, which is reinforced in the drying stage of the load. This provides thermal stability to the particles of the micro-conglomerates under conditions of rapid heating of the pulverized dry load, in the roasting-melting stage. The close contact of sulphate and oxide components with sulphides and carbon, in microconglomerate volumes, provides a significant acceleration of the de-sulfurization process of the charge and decomposition of the higher iron oxides in the roasting-melting stage. the pulverized load in a suspended state, at temperatures of 1250-1350 ° C. The acceleration of the processes of decomposition of sulfates and higher oxides of iron, at temperatures of 300-500 ° C lower than the temperatures of their thermal decomposition is stipulated by the intensive flow of chemical interaction of the following types in volumes of micro-conglomerates of non-homogeneous particles: Me1S04 + Me2S? Me1 0 (Me1) + Me2 0 (Me2) + S02; Me 0 + Me2 S? Me1 O (Me1) + Me2 0 (Me2) + S02; (2) Fe203 + MeS? Fe304 + MeO + S02; (3) Fe304 + MeS? FeO + MeO + SO2; (4) MeSO4 + C? MeO (Me, MeS) + CO2 + SO2; (5) MeO + C? Me + CO; (6) Fe2O3 + C? Fe3O4 + CO; (7) Fe3O4 + C? FeO + CO; (8) The disadvantages of the known method are the low recovery of lead in metallic lead, low specific capacity of the process and, at the same time, high specific consumption of energy vehicles (gas containing oxygen, carbon materials and electric power). The mentioned disadvantages are determined by the fact that the known method does not provide a sufficiently high content and optimum sizes of "complex", thermally stable micro-conglomerates, in the dry charge supplied in suspended state to the roasting-melting stage. These two factors are stipulated by uncontrolled processes of adhesion or disintegration of the particles of the micro-conglomerates, in the drying stage of the wet load. At a load moisture, which is supplied to the drying step, comprising 2-7%, regardless of the content of binder components therein, there is not enough free moisture to form bonds between particles, which are sufficient for mechanical stability and thermal of the micro-conglomerates formed. This leads to the disintegration of the mechanically unstable micro-conglomerates and the deterioration of the thermally unstable micro-conglomerates in the stages of drying of the load and roasting-melting. As a result there is the decrease in the particle content of the "complex" micro-conglomerate and the increase in the mass portion of the individual particles dispersed in the charge, in the roasting-melting stage. At a higher moisture content of the charge supplied to the drying step, the amount of free moisture is sufficient for the formation of a considerable number of stable bonds between particles. However, the uncontrolled adhesion of particles in the material drying process leads to the formation of coarse-grained structures in the dry charge, with the possible formation of extremely large clumps of adhered particles, whose roasting-melting in a suspended state is impossible without additional granulation. Both, the low content of thermally stable "complex" micro-conglomerates in the dry charge, supplied to the roasting-casting stage and their extremely large sizes greatly reduce the efficiency of the processing of lead-containing materials with an increased portion of sulfates, higher oxides of iron and zinc oxides, by the known process. The low portion of "complex" micro-conglomerates in the dry charge reduces the degree of contact between the non-homogeneous particles and the reagents and the large sizes of the micro-conglomerates decrease the rate of their heating in the roasting stage. casting the load. Both factors lead to a reduction in the intensity of the interactions at low temperature between the components of the load, according to the reactions (1) - (8) and the stipulated need to increase the temperature of the roasting-melting up to 1400- 1450 ° C for a more complete decomposition of the thermally stable sulphates and the increase of the fluidity of the molten oxides with increased content of higher iron oxides. The increased temperatures of roasting-roasting lead to a relatively high specific consumption of pulverized coal fuel and oxygen for its oxidation and to a considerable increase in production of recycling powders, thus preventing the reduction of the content of higher iron oxides in the foundry of dispersed oxides. The viscosity of the molten oxides, saturated with higher iron oxides, increases, while there is a reduction of the lead oxide in the layer of ground carbon material. As a result there is an increase in the decelerating effect of the filtration process and reduction of the molten oxide, worsened by a considerable absorption of heat for the reduction of the higher iron oxides. The maintenance of a high fluidity and the increase of the degree of reduction of the molten oxide under these conditions, requires a heat input or a reduction of the supply of molten oxides to the process of the reduction stage. Thus, the known method does not provide an effective realization of the interactions at low temperature of the components of the charge, in the roasting-melting stage and an additional effective reduction of the molten oxides in the reducing layer of ground coal.

Therefore, one of the most significant factors in reducing the efficiency of the known process is the sub-estimation of the lower limit of the recommended range of free moisture content in the wet load, supplied to the drying process. Additional factors for reducing the efficiency of the known process could be the use of carbon materials recommended for the formation of the ground carbon reducing layer. The use of coke with the lowest reaction capacity, of a quantity of carbon materials, stipulates a relatively low rate of reduction of the molten oxide during its filtration through the ground reducer layer, thus limiting the specific capacity of the process . To increase the reduction rate, the temperature increase of the molten oxide is required. However, the increase of its temperature in the roasting-melting stage of the load leads not only to an increase in the specific consumption of energy vehicles (pulverized fuel and oxygen for combustion), but also to the decrease in the recovery of lead in metallic lead, at the expense of an increase in the degree of lead transfer to roasting-smelting powders. Therefore, the increase in the portion of recycle powders in the load could reduce the specific capacity of the process to a greater degree than the increase in the temperature of the molten oxide in the roasting-melting stage, which allows its increase. The reaction capacity of coal is higher than that of coke. However, in contrast to coke, not all carbons have thermal stability under conditions of rapid heating and when they reach the surface of the slag bath they could deteriorate. Therefore, the permeability of the ground carbon reducing layer for the dispersed molten oxide is significantly reduced or completely destroyed. Correspondingly, there is an increase in the surface and in the flow rate of the reduction reactions. This leads to a corresponding decrease in the recovery of lead in metallic lead and the specific capacity of the process (until its complete failure). In addition, the need to increase fluency and, correspondingly, the Molten oxide temperature, by decreasing the permeability of the ground gear, stipulates the increase of the specific consumption of the energy vehicles, which is inevitable in this case. As a basis for the invention, the task of changing the known method of processing materials containing lead, with an increased concentration of thermally stable sulphates and higher iron oxides, was established to increase the recovery of lead as metallic lead and the specific capacity of the lead. process, with a simultaneous reduction of the specific consumption of energy vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS Figures 1 and 2 graphically represent the dependence of the cake-forming capacity of the coals on their content, in dry mass, total carbon and volatile. Figure 3 shows the main scheme of the unit in which the method of the present invention is carried out.

DESCRIPTION OF THE INVENTION The assigned task is achieved by the fact that in the procedure for processing materials containing lead, which includes preparation of the load by a rigorous mixing of wet sulfides and oxidized lead containing materials with fluxes and carbon material, in which the ratio mass of the total amount of sulfur and elemental sulfur and pyrites, to the total sulfur content in the charge, comprises 0.08-0.87 and the pulverized coal material, which has an activation energy of the gasification reaction of coal, within the range of 56-209 kJ / mol, is introduced as a reducer, based on 4-12 kg of pure carbon per 100 kg of ferric iron and 20-140 kg of pure carbon per 100 kg of sulfur as sulfur in the cargo; drying of the wet load produced up to a residual moisture content of less than 1%; roasting- melting of the dry charge in suspended state in oxygen atmosphere, with production of dispersed molten oxide and mixture of dust and roasting-melting gases; reduction of the molten oxide dispersed in its filtration through the heated particle layer of the ground coal reducer, with a grain size of 2-50 mm, with production of metallic lead, molten oxide containing zinc and gases, mixed with powders and roasting-melting gases; separation of the mixture produced from powders and reaction gases with return of the powders to the roasting-melting stage; the dry load is subjected to granulation and classification and the fraction isolated from the dry load is supplied to the roasting-melting stage; Not less than 90% of its mass is composed of particles with a grain size of 0.01-0.10 mm. It is advisable that the content of free moisture in the load, in its preparation stage, is 8-16%. It is reasonable that as reducing charcoal, the dispersed molten oxide reduction stage, carbon with a total carbon content in the dry mass, from about 49 to about 80% and a volatile content from about 11 to around 27%. The achievement of the assigned task in the realization of the proposed solutions is provided by the following factors: - formation of a load micro-structure with a high proportion of thermally stable micro-conglomerates, of non-homogeneous particles, including components of sulfate, oxide, sulfur and carbon; - stabilization of the optimum fraction composition and micro-structure of the dry charge, supplied to the roasting-melting stage in the suspended state; - intensification of the low temperature interactions of the sulphate and oxide components with sulphides and carbon in the roasting-melting stage of the load, in a suspended state; - intensification of the reduction of the molten oxide, in the stable maintenance of the porous structure and permeability of the reducing layer of ground coal.

By morphological investigations of the load, it was found that the minimum size of the "complex" micro-conglomerates of non-homogeneous particles comprised about 0, 01 mm. The most dispersed cargo fractions comprise separate, non-associated particles or micro-conglomerates from individually dispersed, highly dispersed particles of lead-containing materials that possess enhanced adhesive properties (such as dusts, residues, suspensions). From the analysis of the results of the experimental casting, it is known that the increase of the portion of fine fractions, with particle sizes less than 0.01 mm, as well as the increase of the coarse fraction with individual and associated particles, with a grain size greater than 0.1 mm in the dry load, leads to the reduction of the rate and degree of transformation of its components, in the roasting-melting stage in a suspended state and prevents achieving the assigned task. The negative effect on the processing rates of the increased portion of the fine and coarse fractions is successfully eliminated by the introduction of successive granulation and dry charge classification operations, before being supplied to the roasting-melting stage. The combination of granulation and classification operations provides the production of a fraction isolated from the dry load, not less than 90% of the mass of the particles is in the range of 0.01-0.10 mm, which allows: in the dry charge, after grinding the micro-conglomerates of non-homogeneous particles, the inclusion of sulphate, oxide, sulfur and carbon components; - limit the entry of excessively fine individual particles (less than 0.01 mm) and excessively thick (greater than 0.10 mm) and micro-conglomerates that go to the roasting-melting stage, which prevent the increase in the degree of desulfurization of the charge and decomposition of the higher oxides of iron in the roasting-casting stage, in processing modes at reduced temperature.

Therefore, the stabilization of the fraction of the dry filler composition, within the prevailing particle size range of 0.01-0.10 mm, allows an effective solution of the assigned task. The increased direct recovery of lead to metallic lead, the increase of the specific capacity of the process and the simultaneous reduction of the specific energy consumption, are achieved at the expense of: - prevention of poor formation of matte ("lumps"); -decrease of trapped dust and the portion of foundry recycling powders, in the charge; -increase in the degree of reduction of the lead from the molten oxide fluid in the layer of ground carbon material; -decrease in fuel consumption of powdered coal and oxygen for combustion and electrical energy, by compensation for heat losses in reactions of higher iron oxides in the carbon reducing layer. The decrease of the lower limit of the particle sizes in the dry charge, less than 0.01 mm reduces the degree of interaction flow of its components at low temperature, in the roasting-melting stage, in the reactions (1) - (8), due to the decrease in the portion of "complex" micro-conglomerates in the load. This stipulates the need for the temperature increase in the process. In addition, there is the increase in the mechanical transport of fine particles within the roasting-smelting powders. In the aggregate, this leads to a decrease in the recovery of lead to metallic lead, the decrease in the specific capacity of the process and the increase in the specific consumption of energy vehicles. The increase of the upper limit of the size of the particles of the dry charge, less than 0.01 mm reduces the degree of flow of the interactions at low temperature of its components in the roasting-melting stage, at the expense of the reduction rate of the heating of the coarse particles and the decrease of the total reaction surface of the components, that too stipulates the need to increase the temperature of the process and prevents the achievement of the assigned task. The decrease in the mass portion of the particles, with grain size from 0.01 to 0.10 mm, which is less than 90%, as is the case of the change of limits of the optimum particle size range of the particles , results in the degree of reduction of the flow of interactions at low temperature of its components, in the roasting-melting stage. It can also happen both at the expense of the decrease in the portion of "complex" micro-conglomerates, and at the expense of the increase of extremely thick individual particles and micro-conglomerates in the charge. Both factors stipulate the need for an increase in the temperature of the process. As a result, there is a decrease in the recovery of lead to metallic lead and increase in the specific capacity of the process and increase in the specific consumption of the energy vehicles. According to the patented process, careful mixing of the materials is required in the wet load preparation stage to reach a free moisture content in the load mixture of 8-16%. Based on the experimental data, this allows: 1) to form a homogenous micro-structure in the charge, with a large portion of micro-conglomerates of non-homogeneous particles, including components of sulfate, oxide, sulfur and carbon; 2) forming a sufficient amount of stable bonds between non-homogeneous particles, providing thermal stability of "complex" micro-conglomerates in the roasting-melting stage of the dry charge. The range of free moisture content is optimal, because it provides the largest significant increase of the portion of "complex" micro-conglomerates in the load, in the stage of its preparation and strengthening of those micro-conglomerates, in the wet load drying stage. At a moisture content lower than 8% there is a decrease in the portion of "complex" micro-conglomerates in the wet load, supplied by the drying of the load, as well as the decrease in mechanical and thermal stability of such micro-conglomerates in the dry load. Reduces the degree of flow of the interactions of the components of the load in the roasting-melting stage and leads to the deterioration of the indices of the process, within the framework of the assigned task. At a free moisture content of 8% and more, the portion of the "complex" micro-conglomerates in the wet load, supplied by the drying of the load, increases markedly. There is also an increase in the mechanical and thermal stability of such micro-conglomerates in the dry load. Despite the fact that, in this case as well as in the prototype, there is uncontrolled adhesion of particles in the drying stage, the use of successive operations of granulation and classification of the dry load in the patented process excludes the entry of extremely coarse fractions, to the roasting-casting stage. Therefore, the possibility of conducting the process with maximum effectiveness is provided. The increase in the free moisture content of more than 16% in the load is impractical, because it does not lead to a noticeable increase in "complex" micro-conglomerates in the dry load, in the roasting-melting stage and, correspondingly, to the increase in the indices of the process, within the framework of the assigned task. At the same time, the evaporation of excess moisture requires the increase of fuel consumption for the drying of the load, that is, it increases the total specific consumption of the energy vehicles. As the ground carbon reducer of the molten oxide dispersed from the roasting-melting stage of the load in the prototype, coke or coal is suggested. Due to the presence of active (volatile) hydrocarbons and much lower activation energy of the gasification reaction of solid carbon, coal usually has a greater capacity for reduction, compared to coke. However, in contrast to coke, not all coal classes have thermal stability and, under conditions of rapid heating, can deteriorate on the surface of the slag bath, which is not taken into consideration in the prototype. At the same time, the deterioration of coal could not only reduce the dramatic degree of reduction of the molten oxide in the carbon reducing layer, but also completely alter the flow of the reduction process.

The thermal stability of coal is directly connected to its ability to form cake during calcination. The higher the cake's carbon-forming capacity, the higher is its thermal stability. Based on this interrelation and the analysis of experimental data, the optimum range of quality of the coals, which have a sufficiently high thermal capacity, was determined. According to the patented process, the use of ground carbon reducer is reasonable, with the total carbon content in the dry mass, from around 49% to around 80% and, volatile from around 11% to around 27% . The use of coal, with the specified range of total carbon and volatile content, as a reducer of ground coal, increases the effectiveness of the process reduction stage, at the expense of the increase in reducing activity in the maintenance of the developed surface reaction. and high permeability of the ground reducing layer for the dispersed molten oxide. This allows an additional increase in the recovery of lead to metallic lead and the specific capacity of the process, without raising the temperature of the molten oxide, provided by the additional economy of the specific consumption of the energy vehicles. On the other hand, the total carbon in the dry mass of coal comprises solid carbon and volatile carbon and, on the other hand, the solid carbon and the volatiles comprise the base of the dry mass of coal. Because of this, the recommended ranges of total and volatile carbon content in the dry mass of coal are closely connected and, therefore, it is reasonable to consider them together. To the reduction of the total carbon content in the dry mass of coal, to less than 52% and with the increase accompanied by the content of volatiles in that mass, greater than 27%, the capacity of cake formation of the coal in the calcination and its thermal stability under conditions of rapid heating, decrease remarkably. The increase in the degree of deterioration of the lumps of ground coal, on the surface of the slag bath, reduces the permeability of the carbon reducing layer. As a result, the rate of reduction of molten oxide, the degree of recovery from lead to lead is interdependently reduced metallic and the specific capacity of the process. In addition, the reduction of the intensity of the process reduction stage leads to an increase in the specific consumption of the energy vehicles, stipulated by the need to increase the fluidity and, correspondingly, the temperature of the molten oxide, as well as compensation for the increased heating losses, by its reduction and deposition. With a reduced content of solid carbon in the dry mass of coal to more than 80% and the reduction of the content of the volatiles to less than 10%, it also significantly reduces the capacity of cake formation of the coal when calcined and its thermal stability , under conditions of rapid heating. It is determined by the optimum nature of the calcination of the coals, stipulated by the presence in their content of bituminous substances - products of transformation of waxes, resins and fatty substances contained in the creators of coal from plants. The portion of such substances is reduced in coals with a low degree of metamorphism - lignites, as well as in coals with a high degree of metamorphism - anthracites. The dependence of the cake formation capacity of the coals on their content, in the dry mass, of total carbon and volatile, is represented in standard units, given in Figures 1 and 2. It is seen in the data presented that the coals recommended in the patented process, with a total carbon content in the dry mass, from around 49% to around 80% and a volatile content from around 11% to around 27%, possess the highest degree of capacity of cake formation. As it was described, the reduction of the capacity of cake formation and thermal stability of the coal, leads to the deterioration of the indices of the process, within the framework of the assigned task. The procedure is carried out in the unit, whose main scheme is represented in Figure 3. The unit consists of a vertical reaction duct 1, with a rectangular cross section in the roof, in which the burner 2 has been installed to supply load, oxygen, recycled powders and ground coal reducer; the partition vertical wall 3, with copper cooling elements separating the reaction duct 1 from the exhaust pipe 4, maintains a separation of gas over the slag bath to extract the reaction gases; the electric furnace 5, adjacent to the casting chamber and separated therefrom by vertical partition 6, submerged within the slag bath and provided with copper elements cooled by water; the hearth 7, common for the reaction duct 1, the electric furnace 5 and the gas exhaust pipe 4; the belt with jacket 8 and facilities for extracting the cast products 9. The procedure is carried out in the following manner. Using data from the chemical analysis of materials containing lead, which could be lead concentrates, powders, wastes and suspensions from hydrometallurgical production, battery paste, metallic lead refining recycles and other materials, the proportions and materials to be mixed are calculated in such a ratio, in which the mass ratio of the total amount of sulfur, elemental sulfur and pyrites, the total sulfur content in the charge will be 0.08-0.87. To the mixture produced from wet materials containing lead, fluxes (limestone, quartz sand and the like) and carbon powder reducer are added. As carbon powder reducer could be used different types of coals (lignite, coal and wood charcoal), coal concentrates produced from coal slag after the Waelz process, coke production waste and others. In order to achieve the optimum combination of heat release and absorption areas in reaction reactions of the components of the charge, in the roasting-melting stage, it is reasonable to introduce pulverized coal materials with activation energy of the gasification reaction of coal within the range of 56-209 kJ / mol. The addition of pulverized coal material is carried out at a rate from 4 to 12 kg of pure carbon per 100 kg of ferric iron and from 20 to 140 kg of pure carbon per 100 kg of sulfur sulfur in the charge. The load is produced with a free moisture content of 8-16% and homogenized by careful mixing of the materials. This allows to form a homogeneous micro-structure in the load, with a large portion of "complex" micro-conglomerates of non-homogeneous particles, including sulfate, oxide, sulfur and carbon components. A free moisture content in the load less than 8% it is required, first, to moisten the load at its minimum level and then to effect its homogenization. A content of free moisture in the load greater than 16% is required, first, to conduct its homogenization and, then, to remove excess free moisture (for example, by filtering the material), to avoid excessive fuel consumption, necessary to dry the load. The homogenized wet load is dried, where it is dried to a residual moisture content of less than 1%. The dry load produced, containing coarse fractions of adhered particles, is subjected to granulation and the pulverized granulated material, to classification. The coarse fraction of the powdered dry load, with prevalence of particles with grain size greater than 0.10 mm, are returned for granulation, the fraction dispersed with particles with prevalent grain size less than 0.01 mm are returned to the stage of preparation of the wet load and the fractionation, not less than 90% of mass, which is composed of particles with grain size of 0.01-0.10 mm - to the roasting-melting stage. This provides conservation of the pulverized dry load, supplied to the roasting-melting stage, a considerable portion of thermally stable "complex" micro-conglomerates, formed in drying preparation stages of the wet load. At insufficient caloric capacity of the dry charge, the necessary amount of pulverized coal fuel is introduced into it. As such fuel, the same pulverized coal material that was introduced into the wet filler could be used as a reducer of the higher iron oxides and sulphates at the stage of its preparation or other pulverized coal material having high calorific value. Before supplying it to the roasting-melting stage, the powders of the recycled and ground coal reducer process are introduced into the charge, with a grain size of 2-50 mm, more preferably, 5-20 mm. As a coal-grinder reducer, it is possible to use materials other than coal-coal, coke or petroleum coke, coal slag after the Waelz process, wood charcoal and others. However, according to the patented process, it is more preferable to use as a grinding agent for ground coal, mineral carbon with a total carbon content, in dry mass, from about 49 to about 80% and from about 11 to about 27% volatiles. The coals of such quality possess a sufficient cake formation capacity and thermal stability, allowing the formation of a porous, stable structure of the ground carbon reducer, with development of surface reaction and high permeability for the reduction of the molten oxide. Due to the presence of the hydrocarbon active component and reduced activation energy of the coal gasification reaction, such carbons are a more active carbon reducing agent than the carbon materials that passed thermal processing (cokes). The pulverized dry load, together with the pulverized coal fuel (if necessary), recycling powders and ground coal reducer, are supplied through the vertical burner 2, inside the reaction duct 1, for roasting-melting, in state suspended in the gas atmosphere containing oxygen. Oxygen consumption is determined at the rate of complete degree of desulfurization and oxidation of sulfides to lead, zinc and iron, to oxides and coal fuel to carbon dioxide and water vapor, with the deduction of the consumption of metal sulfates and oxides of iron, by interaction with sulfur, elemental sulfur and pyrites and carbon from the pulverized coal reducer, according to the stoichiometry of the total reactions: 3Me1SO4 + Me2S? 3Me1O + Me20 + 4S02; (9) 3Fe203 + MeS? 6FeO + MeO + S02; (10) 2MeS04 + C? 2 MeO + C02 + 2S02; (11) 2Fe203 + C? 4FeO + C02; (12) In other words, oxygen consumption is reduced by the amount determined by the amount of oxygen "connected" in sulfates and oxides superiors of iron. In addition, for oxidation of the pure carbon of the carbon reducer, no oxygen is introduced. Under the influence of high temperatures in the reaction pipe, the pulverized load is ignited, heated rapidly to temperatures of 1,250-1,350 ° C, at the expense of the oxidation by oxygen in the gas phase of part of the sulphides and pulverized coal. Because of this, they flow in volumes of "complex" micro-conglomerates of particles in temperature areas of 350-700 ° C, intensive interactions of sulfates and metal oxides (including higher iron oxides) with sulfides and carbon. As a result, there is formed molten oxide, dispersed, with reduced content of higher iron oxides having high fluidity, and the mixture of powders and reaction gases of sulfur dioxide. The ground carbon reducer, supplied together with the load, due to the large sizes of the clods (mainly 5-20 mm), as well as due to the rapid reduction of the concentration of oxygen in the gas phase, by the height of the pipeline of reaction 1 (on the heel of the slag bath, the concentration of oxygen is around 1-2%) does not have time to burn in the reaction duct 1 and forms a porous reducing layer, which is continuously filled, from lumps very heated carbon material, on the surface of the bath, under the burner 2. The dispersed molten oxide, produced during the roasting-melting of the load, is filtered through this layer of ground coal reducer. Therefore, the oxides of lead are reduced to metal, the higher oxides of iron - until wustite and the zinc oxides do not have time to be reduced to a remarkable degree and, together with the wustite and flux components form a zinc slag with content depleted of lead. The copper oxides as well as the lead oxides are reduced in the reducing layer of carbon, to metal and transferred to metallic lead and sulfides of non-ferrous metals, present in the dispersed foundry of the roasting-melting, they are distributed between metallic phases and of slag (with a degree of desulfurization of the load greater than 90-94%) or form the phase of matte ("lumps") dispersed. The gaseous products The reduction reactions (CO, CO2 and zinc streams) start from the carbon reducing layer and mix with gases and roasting-smelting powders. The lead-containing zinc slag containing suspended, dispersed metallic lead (and matte if formed) material flows into the electric furnace 5, adjacent to the reaction duct 1, below the partition 6, made of elements of copper cooled by water and submerged inside the slag bath. In the electric furnace 5, the suspended, dispersed material of metal (and matte) is decanted with the formation of phases of casting products: metallic lead, zinc slag with exhausted lead content and polymetallic matte, if it is formed. As usual, the matte phase is formed when materials containing lead containing increased amounts of copper are processed. This allows a gross recovery of metallic lead, with recovery of excess copper from the processing of materials containing lead in the polymetallic matte, directly in the unit. After decanting the zinc slag, the metallic lead (and matte) is extracted from the electric furnace, through the facilities to extract the smelting products 9 and transfer them for further processing, by known procedures to produce marketable products (not they are shown in Figure 3). The metallic lead is refined, the zinc slag undergoes Waelz processing, with zinc recovery in oxidized zinc fumes, the polymetallic matte is converted to raw copper. The reaction gas mixture produced and the roasting-toothing gases pass below the partition 3, inside the exhaust gas duct 4, adjacent to the reaction duct 1. In the exhaust gas duct 4, the reaction gases are post-burned to complete the oxidation of the carbon monoxide and the zinc streams and to cool them at the expense of heat exchange with the surfaces of the water-cooled elements installed in the duct. The mixture of reaction gases and powders, cooled to 800-1,000 ° C, goes to a waste heat boiler, where they are cooled to 400-500 ° C and then - inside the electrostatic precipitator (not shown in Figure 3) , where the dust is separated from the reaction gases of sulfur dioxide and returned to roasting-casting together with the load. Sulfur dioxide gases are sent for sulfur use, with the production of marketable products (sulfuric acid, elemental sulfur, sulfuric anhydride or salts). For better understanding of the present invention Examples are given that illustrate the proposed method. EXAMPLE 1 (according to the prototype) In the semi-industrial plant, according to the known method, a load prepared from lead sulfide concentrates, lead powders, lead-producing zinc waste, battery paste, was processed, quartz and lime fluxes, with a mass ratio between the total amount of sulfur, elemental sulfur and pyrites, to the total sulfur content, which was 0.6. As a reducer of sulfates and higher iron oxides, powdered chestnut coal was introduced into the charge, with an activation energy of the coal gasification reaction of 135.2 kJ / mol, at the rate of 10 kg of pure carbon per 100 kg of ferric iron and 80 kg of pure carbon per 100 kg of sulfur sulphate. The prepared charge had a composition of: 28.27% lead; 8.29% zinc; 0.97% copper; 13.02% total iron (including ferric iron - 10.33%); 8.01% total sulfur (including sulfate sulfur - 3.09%); 12.01% silicon oxide; 6.01% calcium oxide and a free moisture content of 10.77%. It was dried to a residual moisture content of 0.8% and fed through the burner for roasting-melting in a suspended state, under a technical-grade oxygen atmosphere (96%). To compensate for the low caloric capacity, the amount of pulverized coal used in the preparation of the wet load, which had the following composition, was added as fuel in the load: 43.76% solid carbon, 38.46% volatile and 17.78 of ash, containing 6.4% of iron, 52.1% of silicon dioxide, 5.2% of calcium oxide. Along with the load, the roast-roaster recycling powders were fed into the burner and, as a grinding coal reducer, coke with a grain size of 5-20 mm was used, with the following composition: 86.64% of solid carbon, 4.31% of volatiles and 9.05% of ashes containing: 12.6% of iron, 57.1% of silicon dioxide and 10.3% of calcium oxide.

In the charge, the charge-oxygen flame of the burner that heats the materials containing lead and fluxes transferred into the molten dispersed oxides and coke, have not had time to burn and have fallen on the slag bath surface, forming the one heated upper layer of carbon reducer. The molten oxide dispersed from the roasting-melting charge in the suspended state, which penetrates through this layer, is reduced. Therefore, the oxides of lead to metallic lead, higher oxides of iron - to wustite and zinc that remains in the molten oxide (slag) are reduced. As a result, metallic lead, zinc slag, and dust-laden gases from the reaction duct, which had been cooled and purified from the powder, are produced, and the smelter continuously returns, along with the charge. The melting mode is controlled by the degree of desulfurization of the charge and the temperature of the molten oxide at the lowest point of the flame. For this purpose, the selection of samples fused in the flame, on top of the carbon reducing layer, was carried out and analyzed for their sulfur content. Simultaneously, the temperature at this point was measured, which was controlled by changing the load, the pulverized coal and the oxygen consumption. Totally in the course of the test, 28 tons of dry cargo were processed. The average results of the indices of the effectiveness of the process, within the framework of the assigned task, were obtained and presented in Table 1, Test 1. EXAMPLE 2. According to the procedure applied, the test was carried out as in Example 1 , but differs by the fact that the load was dried to a residual moisture content of 0, 8%, was subjected to granulation under different modes and classification, separating it into three fractions. The coarse fraction of the charge was sent to the second granulation, the fine fraction - to the preparation of the wet load and the average fraction - to the roasting-melting. Depending on the granulation and classification conditions, the upper and lower limits of the grain size range of the portion of the mass of the particles was changed, of which 90% is of the dry load, supplied to the roasting stage - foundry. The results of the smelting are presented in Table 1, Tests 2-6. EXAMPLE 3. The procedure was carried out as in Example 2, but differs in the fact that the dry charge fraction with a prevalent range of particle sizes of 0.01 to 0.1 mm was supplied to the roasting-casting. and the fraction of mass of this fraction in the load was changed depending on the conditions of its granulation and classification. The results obtained are presented in Table 1, Tests 7-8. As seen in the Table (Tests 1-8), the main tasks of the patented process are: the increase in recovery from lead to metallic lead (column 7), the increase of the specific capacity of the process (column 8) and the reduction Specific consumption of energy vehicles (columns 9-12) were obtained simultaneously with the introduction of operations for granulation and classification of the dry load, as a result of which the isolated fraction of the load was supplied for roasting-casting, the 90 % of whose mass are particles with grain sizes of 0.01-0.10 mm. It was seen, in the optimal composition of the fraction of the dry load (compare tests 1, 3-5 and 7): the increase in recovery of lead to metallic lead of 2.5-2.7%, the increase in specific capacity per the load, in 5.3-6.1%, the reduction of specific consumption of energy vehicles in the foundry, of 13.4-14.8%. EXAMPLE 4. The procedure was carried out as in Example 2, under conditions of granulation and classification of the dry load, when 90% of the mass supplied to the roasting-melting of the load was composed of particles with a grain size of 0.01-0.10 mm (test 3), but differs in the fact that the free moisture content in the load, in its preparation stage, was different (2, 8, 16 and 20%) and its drying was made up one and the same residual moisture - 0.8%. As follows from the results obtained, given in Table 2, Tests 9-12, optimum process indices are achieved with a free moisture content in the load of 8-16%, in the preparation stage, due to the isolation of the optimum fraction of the dry load. An additional effect, stipulated by the formation of a stable micro-structure of the load, to the recommended increase of the minimum permissible content of free moisture in the load from 2-8% that represents (compare tests 9 and 10): the increase in recovery of metallic lead lead of 2.0%, the increase of the specific capacity of the load of 0.3%, the reduction of specific consumption of energy vehicles in the foundry, of 1, 6%. EXAMPLE 5: The procedure was carried out as in Example 2, Test 3, but differs in the fact that charcoal of different quality, with the same grain size, was used as ground coal reducer, instead of coking with lumps of grain size from 5 to 20 mm. The results obtained are given in Table 3, Tests 13-17. According to the data received, the use of carbons as reducers of ground coal allows the increase in the effectiveness of the process (compare with test 3) and the maximum additional effect was observed in the recommended range of contents in the dry mass of coal , from about 49 to about 80% of total carbon and from about 11 to about 27% volatiles. The maximum additional effect of the use of coal as a ground carbon reducer was observed in test 15 and is: the increase in lead to metal lead recovery of 2.3%, the increase in the specific capacity of the load of 0, 3%, the reduction of specific consumption of energy vehicles in the smelting of 5.5%. The dry cargo mass processed in each of tests 2-18 was from 22 to 24 tons. Thus, the examples given show that the patented procedure allows to solve the assigned task.

TABLE 1 - Influence of the composition of the dry charge fraction on the indices of processing materials containing lead TABLE 3 - Influence of the quality of the material of coal in Indices of processing of materials containing lead

Claims (3)

1. - A process to process materials containing lead, CHARACTERIZED because it includes preparation of the load by careful mixing of wet materials of sulfur and oxidized lead with fluxes and pulverized coal material, whose mass ratio between total amount of sulfides, elemental sulfur and of pyrites, the total sulfur content of the charge is 0.08-0.87 and the pulverized coal material has an activation energy of the coal gasification reaction, within the range of 56-209 kJ / mol, which is introduced as a reducer based on 4-12 kg of pure carbon per 100 kg of ferric iron and 20-140 kg of pure carbon per 100 kg of sulfur sulphate in the charge; drying of the wet load produced up to a residual moisture content of less than 1%; roasting-melting of the dry charge in the suspended state in an oxygen atmosphere, with production of molten oxide, dispersed and the mixture of dust and gases from roasting-melting; reduction of the dispersed molten oxide and its filtration through the heated particle layer of the ground coal reducer, with a grain size of 2-50 mm, with production of metallic lead, molten oxide containing zinc and gases mixed with powders and roasting-melting gases of dry charge; separation of the mixture produced from powders and reaction gases with return of the powders to the roasting-melting stage of the dry load; the dry load is subjected to granulation and classification and the fraction isolated from the dry load is supplied to the roasting-melting stage; Not less than 90% of its mass is composed of particles with grain sizes of 0.01-0.10 mm.

2. - The process for processing materials containing lead according to Claim 1, CHARACTERIZED by the fact that the free moisture content in the charge, in the stage of its preparation is 8-16%.

3. - The process for processing materials containing lead according to Claim 1, CHARACTERIZED by the fact that it is used as a reducing agent carbon, carbon with a total carbon content in the dry mass of 49-80% and 11-27% volatiles.