RU2629129C2 - Method of processing waste copper production - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: method includes enrichment of the feedstock and to obtain productive bioleaching solution. Thus as the feedstock used stale copper smelting slags production with high contents of metals Cu, Pb, Zn, Sn, Sb, As, Bi, Fe, which is directed to a mechanical refining to obtain a bulk concentrate and tailings. Obtained is subjected to pelletizing and tails heap leaching to obtain a productive with extraction solution it Cu, Zn, Fe, Sb, As and a solid residue. The resulting residue was sent for pyrometallurgical processing to give the crude lead and the slag recycled. Productive bioleaching solution is routed to copper to produce carburizing copper solution and directed to the precipitation therefrom of calcium arsenate and receiving transparent iron oxide pigment.

EFFECT: increased efficiency and depth of processing slag to produce more marketable products.

10 cl, 3 tbl, 2 ex

Description

The invention relates to ferrous and non-ferrous metallurgy, namely to the processing of industrial waste, in particular to the processing of slag and slag waste. It can be used in the processing of industrial products of metallurgical industries.

The current subsoil use strategy is aimed at a balanced consumption of mineral resources with a high degree of complexity of their use, including the disposal of generated (stale) and generated (current production) processing waste (tailings, slag, sludge, dust and gas emissions, etc.). The global trend of deterioration in the quality of the mineral base of non-ferrous metals leads to the involvement in the processing of complex ores with low contents of valuable components, with a variable material composition, with the dimension of mineral emissions from fine to emulsion, with a high proportion of slimy component and other negative factors.

An important task of modern subsoil use is the involvement in the industrial processing of various types of technogenic raw materials with the highest possible degree of utilization, the ability to retrieve useful components in commercial products and reduce the loss of valuable components, to obtain additional by-products, for example, construction purposes from secondary waste, while solving environmental problems caused by the accumulation of huge volumes of waste, the need to alienate large land areas Adea and the costs of waste disposal and storage, continuous monitoring of negative environmental impacts, etc.

In contrast to natural mineral raw materials, technologies and schemes for processing metallurgical slag by known mechanical methods are associated with many difficulties: changing the state of aggregation, reducing the degree of contrast of physical and technological properties, the need for fine grinding to reveal valuable components (and therefore, high energy consumption), and - and hydrometallurgical redistribution of multicomponent phases and aggregates unusual for natural raw materials, etc.

A known method of processing ash and slag waste, including magnetic separation to separate the iron-containing concentrate from the ash, screening the ash with the release of quicklime, ash gravel, coarse and fine sand, then heavy metals are separated from the sand by density separation and subsequent separation of sand and coal by electrical conductivity (Pat. RU 2206626, IPC С22В 7/02, publ. 06/20/2003).

The disadvantage of this method is the low processing efficiency due to losses of associated metals, including rare ones.

A known method of pyrometallurgical processing of copper slag, including the preparation of a mixture of slag, graphitized coke, a copper collector and carbonates of alkali and alkaline earth metals as an activator of the recovery process, melting the mixture in an induction crucible furnace with an inductive graphite heater or pieces of graphite (Pat. RU 2555294 , IPC С22В 7/04 С22В 15/14, publ. 07/10/2015).

The disadvantages of the method are the high economic costs of pyrometallurgy of the entire mass of the material and the inevitable secondary losses of other non-ferrous metals.

The closest in technical solution and the achieved result is a comprehensive method of slag processing, including magnetic separation and gravity enrichment to obtain concentrate and tailings. The tailings are subjected to cavitation treatment and biohydrometallurgical redistribution with constant aeration, providing additional extraction of valuable components present in the slag matrix (Pat. RU 2350666, IPC C22B 7/04, C22B 3/18, publ. 03/27/2009).

The disadvantage of this method is the implementation of the biohydrometallurgical stage in static mode with periodic change of solution, which leads to increased labor and economic costs when processing large masses of feedstock. In addition, cavitation treatment in acoustic mode can lead to inhibition of microorganisms, its implementation will also increase capital and operating costs.

The purpose of the present invention is to increase the efficiency of processing technogenic mineral raw materials by deep waste disposal with the most complete retrieval of valuable components, reducing their losses to a level that allows the use of secondary waste in the construction industry without harming the environment.

The technical result is to increase the efficiency and depth of processing of mineral raw materials with the receipt of additional commercial products.

The essence of the method, achieving the purpose of the invention, is as follows. Stale slag and sludge from copper smelting with elevated metal contents (copper, lead, zinc, tin, antimony, arsenic, bismuth, tellurium, precious metals, iron) are sent to mechanical enrichment by screw separation in the presence of metallized copper and lead components in the initial slag obtaining a collective concentrate sent for further processing in a known manner. The tailings of mechanical enrichment are pelletized to obtain granules with a particle size of 10-12 mm; pelletizing is carried out with liquid glass at a flow rate of 0.3-0.5 kg / t and ash burning local energy coals at a flow rate of 0.6 kg / t. A pile is formed from pelletized material and heap bioleaching is carried out to obtain a productive solution into which copper, zinc, iron, antimony, arsenic, and a solid residue (cake) are transferred, which are sent to pyrometallurgical processing by two-stage melting in a liquid bath (melting in the Vanyukov furnace) with the receipt of rough lead sent to the metallurgical plant of a full cycle, and secondary slag - raw materials for the construction industry. The specified pyrometallurgical method (smelting in a Vanyukov furnace), unlike a number of other processes (KIVCET, Kaldo), does not require deep drying of the starting material.

The bioleaching solution is sent to cementation on iron shavings (scrap metal) to produce cemented copper and an iron-containing solution, from which calcium arsenate is precipitated in a known manner, and the secondary solution after precipitation is a ferrous sulfate solution aimed at producing high-quality transparent transparent iron oxide pigment (from 1 t of iron sulfate, it is possible to obtain 250 kg of pigment). Pigment is used for 90% of the secondary solution, and the rest is used as a circulating solution in bioleaching to feed microorganisms. For carburizing copper as iron chips, it is possible to use iron scrap.

Heap bioleaching is carried out using a solution of a bacterial complex containing strains of thionic iron-oxidizing microorganisms Acidithiobacillus ferrooxidans and thionic sulfur-oxidizing microorganisms Acidithiobacillus thiooxidans isolated from the material of the original stagnant slags.

Methods of isolation, accumulation (cultivation), quantification, determination of activity and the study of microorganisms are described in detail in literature (for example, lit. 1-4). The obtained strains are mixed in a 1: 1 ratio with the creation of a biocomplex of microorganisms, which are then cultivated on a 9K nutrient medium (Table 1) to achieve the required specific concentration of bio-cells at the level of 10 ⁶ -10 ⁷ cells / ml for 10 days. The initial parameters of the bacterial solution: pH 1.8-2.1, Eh 640-680 mV, temperature 30-35 ° C. The oxidation rate of iron (II) of the resulting complex was 23-24 g / l per day. The specific consumption of the bacterial solution is 0.5-2 l / h per 1 m ^{2 of} the stack surface (12-48 l / day for 1 m ² ), the irrigation duration is 6-12 months, followed by the exposure of the stack without irrigation for 3 months .

The advantages of the method

- conditioning the nutrition of the subsequent pyrometallurgical redistribution of the bioleaching cake according to the content of copper and arsenic;

- disposal of stale slag with the receipt of additional products - collective copper-lead concentrate screw separator, cementation copper, high-quality iron oxide pigment, crude lead, calcium arsenate;

- the exception of the energy-consuming operation of copper electrolysis with preliminary concentration of the bioleaching solution up to 40-50 g / l

- exclusion from the pyrometallurgical redistribution of the energy-intensive operation of deep drying of the material supplied to the smelting;

- the possibility of cementing the use of an anthropogenic product - iron scrap;

- suitability of secondary slag pyrometallurgy for use in the construction industry;

- the possibility of disposal of various lead-containing technogenic raw materials.

Example 1

The initial slags contained total iron 7.8%, total sulfur 10.54%, copper 9.19%, zinc 0.93%, arsenic 0.58%, lead 20.90%, antimony 1.14%. The slag contained virtually no metallized components of copper and lead; therefore, pelletized with liquid glass at a flow rate of 0.3 kg / t and ash at a flow rate of 0.6 kg / t, the material was fed to the stacking formation, bypassing the stage of mechanical enrichment on screw separators.

Bioleaching was carried out using a solution biocomplex strains of microorganisms Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in the ratio 1: 1, isolated from stale slag and corresponding own biocenosis, which were cultured in a nutrient medium 9K for 10 days to achieve specific biokletok concentrations at 10 ⁶ -10 ⁷ cells / ml. The resulting solution of the biocomplex with the initial parameters of pH 1.8-2.1, Eh 650 mV and a temperature of 32 ° C was irrigated with the formed stack for 12 months at a specific flow rate of the bacterial solution of 1.2 l / h per 1 m ^{2 of the} surface of the stack (28, 8 l / day for 1 m ² ), after which the irrigation was stopped and the stack was kept for 3 months. The copper recovery into the leachate was 88.14% with a residual copper content of 1.09% (Table 2). Extraction of zinc in solution - 78.49%, aluminum oxide - 55.71%. The arsenic content in cake decreased by 65.52%, antimony by 21.05%.

Cemented copper, calcium arsenate and a solution of iron sulfate directed to the production of transparent pigment were obtained from a productive bioleaching solution by precipitation on iron chips. In the pyrometallurgical redistribution, crude lead was obtained (lead content - 61.00%, copper - 2.90%, arsenic - 0.10%).

Example 2

The initial slags contained total iron 10.57%, total sulfur 4.32%, copper 3.05%, zinc 1.65%, arsenic 8.78%, lead 39.96%, antimony 3.61%. In the composition of the slag, 5.0% of the metallized phases of lead and copper were present; therefore, the initial slag was fed to gravity enrichment on a screw separator. As a result of gravitational enrichment, a heavy fraction was obtained with a lead content of 52.39%, copper - 4.88%, arsenic - 1.54% and a light fraction with lead content of 39.29%, copper - 2.95%, arsenic - 9, 17% The light fraction of the sluice was pelletized with liquid glass at a flow rate of 0.5 kg / t and ash at a flow rate of 0.8 kg / t, after which the material was fed to the formation of the stack. Bioleaching was carried out using a solution biocomplex strains of microorganisms Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in the ratio 1: 1, isolated from stale slag and corresponding own biocenosis, which were cultured in a nutrient medium 9K for 10 days to achieve specific biokletok concentrations at 10 ⁶ -10 ⁷ cells / ml. The resulting solution of the biocomplex with the initial parameters of pH 1.82, Eh 670 mV and a temperature of 32 ° C was irrigated with the formed stack for 12 months at a specific consumption of the bacterial solution of 1.2 l / h per 1 m ^{2 of the} surface of the stack (28.8 l / day . on 1 m ² ), after which the irrigation was stopped and the stack was kept for 3 months. The extraction of copper into the productive leaching solution was 76.27% with a residual copper content of 0.70% in the cake (Table 3). Extraction of zinc in solution - 80.00%, alumina - 32.00%. The arsenic content in cake decreased by 57.92%, antimony by 44.19%.

The content of components such as Fe ₂ O _{3 total} , S increases due to their introduction with a nutrient medium of 9K. Cemented copper, calcium arsenate and a solution of iron sulfate directed to the production of transparent pigment were obtained from a productive bioleaching solution by precipitation on iron chips. In the pyrometallurgical redistribution, crude lead was obtained (lead content - 70.00%, copper - 1.90%, arsenic - 0.20%).

Bibliography

1. Karavayko G.I. Microorganisms of ore deposits, their physiology and use in hydrometallurgy. Abstract. diss. for a scientist, doctorate degrees. biol. sciences. M., 1973.

2. Biotechnology of metals. Practical Guide (Scientific editors: G.I. Karavayko (USSR), J. Rossi (Italy), A. Agate (India), S. Grudev (Bulgaria), Z.A. Avakyan (USSR). M: Center The international project of the State Committee for Science and Technology in accordance with the program of the international project of the USSR / UNEP “Biotechnology of metals as an economically acceptable method of rational use of mineral resources”, 1989. 375 p.).

3. Polkin S.I., Adamov E.V., Panin V.V. The technology of bacterial leaching of non-ferrous and rare metals. M .: "Nedra", 1982.288 s.

4. Vasyuchkov Yu.F. Mining Biotechnology: Textbook. M.: Publishing House "Mountain Book", 2011. 351 p.

Claims (10)

1. The method of complex processing of slag, including enrichment and bioleaching to obtain a productive solution, characterized in that the source slag is used stale slag of copper smelting with a high content of metals Cu, Pb, Zn, Sn, Sb, As, Bi and Fe, which sent to mechanical enrichment to obtain collective concentrate and tailings for pelletizing and heap bioleaching to obtain a productive solution with extraction of Cu, Zn, Fe, Sb, As and a solid residue, which are sent to pyrometallurgical processing to produce crude lead and secondary slag, while a productive bioleaching solution is directed to copper cementation to produce cemented copper and a solution aimed at precipitating calcium arsenate from it and obtaining transparent iron oxide pigment. 2. The method according to p. 1, characterized in that the mechanical enrichment is carried out by screw separation. 3. The method according to p. 1, characterized in that the mechanical enrichment is directed to slag in the presence of metallized components of copper and lead. 4. The method according to p. 1, characterized in that the pelletizing is carried out to obtain granules with a particle size of 10-12 mm at a flow rate of liquid glass of 0.3-0.5 kg / t and ash burning local energy coal 0.6-0.8 kg / t 5. The method according to p. 1, characterized in that a pellet for heap bioleaching is formed from pelletized material. 6. The method according to p. 5, characterized in that heap bioleaching is carried out by stack irrigation with a solution of a bacterial complex of microorganism strains Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in a 1: 1 ratio, cultured on 9K medium to achieve a specific concentration of 10 ⁶ -10 ⁷ cells / ml for 10 days, with initial pH values of 1.8-2.1, Eh 640-680 mV and a solution temperature of 30-35 ° C. 7. The method according to p. 6, characterized in that the specific consumption of the solution of the bacterial complex is 0.5-2 l per hour per 1 m ^{2 the} surface of the stack. 8. The method according to p. 6, characterized in that heap bioleaching is carried out by irrigation of the stack with a solution of the bacterial complex for 6-12 months, followed by exposure of the stack without irrigation for 3 months. 9. The method according to p. 1, characterized in that the pyrometallurgical processing of the solid residue of bioleaching is carried out without preliminary drying in two stages by melting in a liquid bath of a Vanyukov furnace to produce crude lead. 10. The method according to p. 1, characterized in that the carburizing of copper is carried out on iron chips.