Comprehensive recovery method of low-grade multi-metal material

Abstract

The invention discloses a comprehensive recovery method of a low-grade multi-metal material. The comprehensive recovery method comprises the following steps: smelting the low-grade multi-metal material in a reinforced smelting furnace; smelting slag enters the echelon reduction volatilization furnace to be smelted; mixing soot obtained by smelting with the waste zinc electrolyte to obtain pulpified liquid; flue gas obtained by smelting and pulpified liquid are subjected to a contact reaction, and the reacted liquid is subjected to gas-liquid separation; carrying out contact reaction on the flue gas obtained after gas-liquid separation and the liquid again; extracting indium from the obtained lixivium by adopting P2O4; adding tannin into liquid after indium extraction to precipitate germanium; and adding alkali liquor into the germanium-deposited solution to neutralize and recover gallium. According to the method, the low-grade multi-metal material is sequentially subjected to echelon oxygen-enriched enhanced reaction smelting, continuous oxidation desulfurization leaching and scattered metal wet recovery by adopting an efficient smelting method, so that the energy consumption is reduced, the smelting efficiency is improved, the recovery rate of metals such as germanium is improved, the resource recovery rate is improved under the condition of relatively low energy consumption, and the economic benefit is increased. And the method has good social and economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of metal smelting, and in particular to a comprehensive recovery method for low-grade multi-metal materials. Background Art

[0002] With the rapid development of high-tech industries, rare metals such as germanium, indium, and gallium are widely used in various fields such as communications, aerospace, automotive, electronics, and new energy. The global demand for rare metals has been increasing year by year. Currently, the materials for recovering rare metals containing germanium and the like mainly include primary resources and secondary resources.

[0003] In terms of primary resources, rare metals are often associated with other minerals. For example, germanium is usually enriched in the leaching residue and replacement residue during the zinc leaching process, as well as the germanium-containing ash produced by coal combustion; the materials for indium recovery mainly include indium-containing slag during the lead and zinc smelting processes, converter slag during the copper smelting process, and electric furnace soot during the tin smelting process; gallium is often associated with bauxite and will enter the Bayer process mother liquor during the alkaline leaching process of bauxite; selenium and tellurium will enter the matte phase during the copper smelting process and be enriched in the anode mud after electrolytic refining; these by-products of the smelting process are usually important raw materials for extracting rare metals.

[0004] During the lead, zinc, and copper smelting processes, most rare metals are often dispersed in the main metal smelting waste slag. This slag has a large quantity. In addition to containing a small amount of copper, lead, and zinc, the content of rare metals such as indium, germanium, and gallium is also relatively low, resulting in the underutilization of multi-metals. The general process for extracting rare metals from slag and ash containing rare metals such as germanium usually adopts a conventional pyrometallurgical volatilization-wet leaching enrichment process. The enriched rare metal slag and ash are then processed through purification-extraction / ion adsorption / precipitation / hydrolysis-replacement / reduction / electrolysis and other processes to obtain the final product. For example, a method for simply and efficiently recovering copper and tellurium from copper tellurium slag disclosed in Patent CN109536712B. However, the existing process has a long recovery process flow, high production costs, low comprehensive metal utilization rate, low resource recovery rate, and causes certain pollution to the environment. Therefore, it is currently technically difficult to recover rare metals from primary resources. For example, the current difficulty in germanium recovery lies in the extraction and preparation of germanium concentrate from primary resources, mainly reflected in two aspects: leaching and separation. In terms of leaching, the most commonly used germanium leaching system at present is the sulfuric acid system. However, during the acid leaching process, germanium is prone to hydrolysis to form germanium dioxide colloid or enter the lattice of silicon dioxide and is difficult to be leached, resulting in generally low leaching rates.

[0005] Therefore, to solve the problem of the comprehensive utilization rate of such low-grade multi-metal materials, it is urgent to solve the efficient separation technology of scattered metals and metallurgical technologies such as enhanced leaching. Developing enhanced, highly stable and deep extraction technologies is of great significance for improving the direct recovery rate and resource utilization rate of scattered metals, and helps to achieve the efficient separation and enrichment of scattered metals. This also has very important practical significance for supplementing the current contradiction between supply and demand of scattered metals. Summary of the Invention

[0006] The present invention aims to overcome the above problems existing in the existing methods for recovering scattered metals, and provides a comprehensive recovery method for low-grade multi-metal materials. The method uses an efficient smelting method to sequentially carry out stepped oxygen-enriched enhanced reaction smelting, continuous oxidative desulfurization leaching and wet recovery of scattered metals on the low-grade multi-metal materials, reducing energy consumption, improving smelting efficiency, and increasing the recovery rate of metals such as germanium. Under the condition of low energy consumption, the resource recovery rate is improved, and it has good social and economic benefits.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A comprehensive recovery method for low-grade multi-metal materials, the steps including: (1) The low-grade multi-metal materials enter an enhanced smelting furnace, and a reducing agent is added for smelting; (2) The smelting slag enters a stepped reduction and volatilization furnace, and a reducing agent and pyrite are added for smelting. The obtained smelting slag is processed to produce ferroalloy; the obtained crude copper alloy is processed to produce crude copper; (3) The soot obtained from smelting and the waste zinc electrolyte are mixed to obtain a pulping liquid; (4) The flue gas obtained from smelting contacts and reacts with the pulping liquid, and the reacted liquid is subjected to gas-liquid separation; (5) The flue gas and liquid obtained after gas-liquid separation are contacted and reacted again; (6) The leaching solution obtained in step (5) is used to extract indium with P2O4; (7) Tannin is added to the liquid after indium extraction to precipitate germanium; (8) An alkali solution is added to the liquid after germanium precipitation to neutralize and recover gallium.

[0008] The method of the present invention mainly includes three stages: steps (1) and (2) are the first stage: stepped oxygen-enriched enhanced smelting and volatilization stage; steps (3) to (5) are the second stage: continuous oxidative desulfurization leaching stage; steps (6) to (8) are the third stage: wet recovery stage of scattered metals.

[0009] In the stepped oxygen-enriched enhanced smelting volatilization section, first in step (1), the inside of the furnace is mainly in a strong reducing atmosphere. The oxides in the materials react with the reducing agent pulverized coal or carbon monoxide to be reduced to lower-valent oxides (GeO, In2O, and Ga2O) and simple substances such as lead and zinc, which volatilize and are then oxidized by the oxygen inhaled from the upper part of the furnace into (higher-valent) oxides and enriched in the soot. Secondly, in step (2), the relatively weak reducing atmosphere inside the furnace is controlled. At this stage, the higher-valent oxides of gallium and part of indium in the smelting slag are reduced by CO in the furnace to lower-valent oxides (In2O and Ga2O) that are easy to volatilize and enter the flue gas, and then are oxidized by the oxygen inhaled from the upper part of the furnace into (higher-valent) oxides and enriched in the soot. Tin in the slag material volatilizes into the flue gas as stannous sulfide, and then stannous sulfide is oxidized into tin oxide in the flue duct and enters the soot.

[0010] The main reactions are as follows: GeO2 + CO = GeO + CO2; ZnO + CO = Zn + CO2; GeO2 + Zn = GeO + ZnO; 2GeO + O2 = 2GeO2; 2Zn + O2 = 2ZnO; In2O3 = 2InO + 1 / 2O2; 2InO + CO = In2O + CO2; 4InO + C = 2In2O + CO2; In2O + O2 = In2O3; Ga2O3 + 2CO = Ga2O + 2CO2; Ga2O + CO = 2Ga + CO2; Ga2O3 + 4Ga = 3Ga2O.

[0011] After the materials undergo the stepped oxygen-enriched enhanced smelting volatilization, lead, zinc, germanium, and indium almost all volatilize into the soot, most of the gallium volatilizes into the soot, and the remaining small amount enters the iron-containing smelting slag; tin in the materials also volatilizes as tin sulfide and then is oxidized to tin oxide to enter the soot for enrichment; at the same time, copper in the materials is produced as crude copper alloy, and iron, etc. enter the smelting slag. The soot and flue gas containing germanium, gallium, indium, and zinc produced in the stepped oxygen-enriched enhanced smelting volatilization section enter the second-stage continuous oxidation desulfurization leaching. After continuous oxidation desulfurization leaching, germanium, indium, gallium, and zinc are leached into the leaching solution, and lead forms lead sulfate to form a precipitate and enters the slag.

[0012] The main reactions occurring in the continuous oxidation desulfurization leaching section are: ZnO + SO2 + 5 / 2H2O = ZnSO3·5 / 2H2O; ZnSO3 + SO2 + H2O = Zn(HSO3)2; ZnO + Zn(HSO3)2 + 4H2O = 2ZnSO3·5H2O; ZnSO3 + 1 / 2O2 = ZnSO4 (oxygen exists in the flue gas and the introduced oxygen); Zn(HSO3)2 + O2 = ZnSO4 + H2SO4 (oxygen exists in the flue gas and the introduced oxygen); In2O3 + 3H2SO4 = In2(SO4)3 + 3H2O; Ga2O3 + 3H2SO4 = Ga2(SO4)3 + 3H2O; MeO·GeO2 + H2SO4 = MeSO4 + H2GeO3; GeO2 + 2H2SO4 = Ge(SO4)2 + 2H2O; GeO + H2SO4 = GeSO4 + 3H2O; ZnO + H2SO4 = ZnSO4 + H2O.

[0013] After the reaction in step (5), the liquid enters the third-stage rare-dispersed metal hydrometallurgical recovery section, and indium, germanium, and gallium are recovered in sequence. The gallium-precipitated liquid mainly contains zinc sulfate. After secondary purification, impurities such as iron, manganese, cadmium, and copper are removed to produce pure zinc sulfate liquid, which can be sold as a product, or used to produce zinc sulfate products and electrolytically produce zinc.

[0014] Preferably, in step (1), the addition amount of the reducing agent is 15 - 25% of the material weight, the temperature in the enhanced smelting furnace is controlled at 1150 - 1300 °C; oxygen-enriched air is blown into the high-temperature molten slag, the oxygen-enriched concentration is 60 - 70 vt%, and the air excess coefficient is 0.85 - 1.0; the smelting time is 60 - 100 min.

[0015] Preferably, in step (2), the mass ratio of the smelting slag to the reducing agent and pyrite is 10:1.5 - 5:1 - 2; the temperature is controlled at 1200 - 1350 °C; oxygen-enriched air is blown into the high-temperature molten slag, the oxygen-enriched concentration is 60 - 70 vt%, and the air excess coefficient is 0.65 - 0.90; the smelting time is 45 - 100 min.

[0016] Preferably, the reducing agent described in steps (1) and (2) is pulverized coal or coke; the enhanced smelting furnace and the stepwise reduction and volatilization furnace are bottom-blown smelting furnaces or side-blown smelting furnaces; the fuel used for smelting is one or more of natural gas, coal gas, and pulverized coal; the combustion-supporting gas used is pure oxygen; the oxygen content in the pure oxygen is 70 - 100 vt%; the pressure when fuel gas and combustion-supporting gas are introduced into the enhanced smelting furnace and the stepwise reduction and volatilization furnace is 0.2 - 0.4 MPa.

[0017] Preferably, in step (3), the mass ratio of soot to waste zinc electrolyte is 1:8 - 12.

[0018] Preferably, in steps (4) and (5), the reaction temperature during the contact reaction is 105°C - 110°C, and the reactor pressure is 0.35 MPa - 0.5 MPa; the final acidity of the desulfurized liquid obtained in step (5) is 0.55 - 0.65 mol / L, and the acidity is controlled by adding concentrated sulfuric acid to the waste zinc electrolyte.

[0019] Preferably, oxygen is introduced during the contact reaction in step (5).

[0020] Preferably, the indium-containing organic phase obtained by extracting indium in step (6) is subjected to multi-stage back-extraction with hydrochloric acid solution to obtain an indium-containing aqueous phase; the indium-containing aqueous phase is displaced with zinc plates to obtain sponge indium, the sponge indium is pelletized and melted to obtain crude indium, and the crude indium is electrolyzed to obtain indium ingots with a purity of 99.99%.

[0021] Preferably, after adding tannin to precipitate germanium in step (7), ZnO is added to neutralize the pH value of the liquid to 1.2 - 2.0, and tannin germanium is produced after filtration; tannin germanium is oxidized and roasted at 500 - 600°C to obtain germanium concentrate containing 15 - 25 wt% germanium, the germanium concentrate is subjected to chlorination distillation and rectification to obtain germanium tetrachloride, germanium tetrachloride is hydrolyzed with deionized water to produce germanium dioxide, germanium dioxide is reduced with hydrogen to obtain metallic germanium, and finally high-purity germanium is produced through zone melting.

[0022] Preferably, the lye in step (8) is a mixed solution of NaCO3 and NaOH. The solution is neutralized with the lye until the pH value of the solution is 3 - 4 to obtain the hydrolysis product Ga(OH)3. Ga(OH)3 is dissolved with HCl to obtain an HGaCl4 solution, which is combined with the chlorination distillation residue to obtain a gallium-containing solution. The solution is extracted with TBP, and the loaded organic phase is back-extracted with NaOH solution to obtain a gallium-containing aqueous phase; NaOH is added to make the solution, and the addition amount is 150 - 200 g / L. Using stainless steel as the cathode and stainless steel / nickel as the anode, electrolysis is carried out to obtain gallium with a purity of 99.99%.

[0023] Therefore, the present invention has the following beneficial effects: (1) The present invention adopts the stepped oxygen-enriched strengthening smelting method to stepwise enrich and recover zinc, lead, germanium, indium, gallium, etc. in germanium-containing materials; compared with the traditional rotary kiln volatilization and fuming volatilization methods, the volatilization rate of rare metals is high. The indium volatilization rate can reach more than 98%, the germanium volatilization rate can reach more than 96%, and the gallium volatilization rate can reach more than 95%. (2) The present invention adopts the stepped oxygen-enriched strengthening smelting method, which improves the smelting efficiency, reduces the flue gas volume during the smelting process, and increases the sulfur dioxide concentration in the soot. The sulfur dioxide concentration in the soot can reach 3% (the sulfur dioxide concentration in the flue gas of the traditional volatilization method is low and unstable), providing favorable conditions for the subsequent direct continuous oxidative desulfurization leaching reaction; (3) The present invention adopts the direct continuous oxidative desulfurization technology, and the germanium-containing rare metal soot in the soot, sulfur dioxide and oxygen in the flue gas directly participate in the reaction with waste dilute acid; this process shortens the soot disposal process, omits processes such as surface coolers, electrostatic precipitators, purification, and absorption in traditional flue gas treatment, greatly reducing the huge disposal equipment, disposal sites, and disposal costs of traditional sulfur-containing soot; realizes the direct resource utilization of sulfur dioxide, avoiding secondary pollution of solid waste; and has good economic benefits; (4) The present invention synergistically couples the stepped oxygen-enriched strengthening smelting method, the direct continuous oxidative desulfurization technology, and the comprehensive recovery method of rare metals, realizing the comprehensive recovery and utilization technology of multiple metals such as zinc, germanium, indium, and gallium in low-grade germanium materials; conforms to the concept of green and low-carbon development and the concept of comprehensive utilization of renewable resources, with remarkable social benefits. Brief Description of the Drawings

[0024] Figure 1 It is the process flow diagram of the present invention. Detailed Embodiments

[0025] The following further describes the present invention in conjunction with the drawings and specific embodiments.

[0026] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in this industry. The methods in the following embodiments, unless otherwise specified, are conventional methods in this field.

[0027] General Embodiment: A comprehensive recovery method for low-grade multi-metal materials, the process is as Figure 1 shown, and the steps include: (1) The low-grade multi-metal material enters the strengthening smelting furnace, and a reducing agent is added for smelting; (2) The smelting slag enters the stepped reduction volatilization furnace, and a reducing agent and pyrite are added for smelting. The obtained smelting slag is processed to produce ferroalloy; the obtained crude copper alloy is processed to produce crude copper; (3) The soot obtained from smelting and the waste zinc electrolyte solution are mixed to obtain a slurried liquid; (4) The flue gas obtained from smelting and the slurried liquid are brought into contact for reaction, and the reacted liquid is subjected to gas-liquid separation; (5) The flue gas and liquid obtained after gas-liquid separation are brought into contact for reaction again; (6) The leaching solution obtained in step (5) is used to extract indium with P2O4; (7) Add tannin to the liquid after indium extraction to precipitate germanium; (8) Add lye to the liquid after germanium precipitation to neutralize and recover gallium.

[0028] As a specific embodiment, the addition amount of the reducing agent in step (1) is 15-25% of the weight of the material, the temperature in the enhanced smelting furnace is controlled at 1150-1300 °C; blow oxygen-enriched air into the high-temperature molten slag, the oxygen-enriched concentration is 60-70 vt%, and the air excess coefficient is 0.85-1.0; the smelting time is 60-100 min.

[0029] As a specific embodiment, the mass ratio of the smelting slag, the reducing agent and pyrite in step (2) is 10:1.5-5:1-2; the temperature is controlled at 1200-1350 °C; blow oxygen-enriched air into the high-temperature molten slag, the oxygen-enriched concentration is 60-70 vt%, and the air excess coefficient is 0.65-0.90; the smelting time is 45-100 min.

[0030] As a specific embodiment, the reducing agent described in steps (1) and (2) is pulverized coal or coke; the enhanced smelting furnace and the stepwise reduction and volatilization furnace are bottom-blown smelting furnaces or side-blown smelting furnaces; the fuel used during smelting is one or more of natural gas, coal gas, and pulverized coal; the combustion-supporting gas used is pure oxygen; the oxygen content in the pure oxygen is 70-100 vt%; the pressure when the fuel gas and the combustion-supporting gas are introduced into the enhanced smelting furnace and the stepwise reduction and volatilization furnace is 0.2-0.4 MPa.

[0031] As a specific embodiment, the mass ratio of the soot and the waste zinc electrolyte solution in step (3) is 1:8-12.

[0032] As a specific embodiment, the reaction temperature during the contact reaction in steps (4) and (5) is 105 °C - 110 °C, and the reactor pressure is 0.35 MPa - 0.5 MPa; the final acidity of the desulfurized liquid obtained in step (5) is 0.55-0.65 mol / L, and the acidity is controlled by adding concentrated sulfuric acid to the waste zinc electrolyte solution.

[0033] As a specific embodiment, oxygen is introduced during the contact reaction in step (5).

[0034] As a specific embodiment, the indium-containing organic phase obtained by indium extraction in step (6) is subjected to multi-stage back-extraction with hydrochloric acid solution to obtain an indium-containing aqueous phase; the indium-containing aqueous phase is displaced with a zinc plate to obtain sponge indium, the sponge indium is pressed into pellets and then melted and cast to obtain crude indium, and the crude indium is electrolyzed to obtain indium ingots with a purity of 99.99%.

[0035] As a specific embodiment, after adding tannin to precipitate germanium in step (7), ZnO is added to neutralize the pH value of the liquid to 1.2 - 2.0, and tannin germanium is produced after filtration; tannin germanium is oxidized and roasted at 500 - 600 °C to obtain germanium concentrate containing 15 - 25 wt% germanium. The germanium concentrate is subjected to chlorination distillation and rectification to obtain germanium tetrachloride. Germanium tetrachloride is hydrolyzed with deionized water to produce germanium dioxide, and germanium dioxide is reduced with hydrogen to obtain metallic germanium. Finally, high-purity germanium is produced through zone melting.

[0036] As a specific embodiment, the lye in step (8) is a mixed solution of NaCO3 and NaOH. The solution is neutralized with the lye until the pH value of the solution is 3 - 4 to obtain the hydrolysis product Ga(OH)3. Ga(OH)3 is dissolved with HCl to obtain an HGaCl4 solution, which is combined with the chlorination distillation residue to obtain a gallium-containing solution. TBP extraction is used. After the loaded organic phase is back-extracted with NaOH solution, an aqueous gallium-containing phase is obtained; NaOH is added to make a solution, and the addition amount is 150 - 200 g / L. Stainless steel is used as the cathode, and stainless steel / nickel is used as the anode for electrowinning to obtain gallium with a purity of 99.99%.

[0037] Example 1: A comprehensive recovery method for low-grade multi-metal materials, the steps are as follows: S1: Stepwise oxygen-enriched enhanced smelting volatilization section: S11: Low-grade multi-metal materials (copper 3%, lead 2%, zinc 5%, indium 0.05%, germanium 0.02%, gallium 0.05%, gold 10 g / t, silver 250 g / t) are mixed with 20 wt% of the reducing agent pulverized coal by weight and enter the enhanced smelting furnace for smelting. The temperature in the furnace is controlled at 1200 °C. Oxygen-enriched air is blown into the high-temperature molten slag through the air duct, with an oxygen-enriched concentration of 65 vt% and an air excess coefficient of 0.90. The smelting time is 75 min; S12: The molten smelting slag enters the stepwise reduction volatilization furnace. After adding the reducing agent pulverized coal and pyrite, the temperature is controlled at 1300 °C. Oxygen-enriched air is blown into the high-temperature molten slag through the air duct, with an air excess coefficient of 0.80, and a stepwise enhanced reduction volatilization smelting process is carried out; the mass ratio of the smelting slag to the reducing agent and pyrite is 10:3:1.5; the smelting time is 60 min; The enhanced smelting furnace and the stepwise reduction volatilization furnace used in S11 and S12 are side-blowing smelting furnaces; the fuel used for smelting is natural gas; the combustion-supporting gas used is pure oxygen; the oxygen content in the pure oxygen is 95 vt%; the pressure when fuel gas and combustion-supporting gas are introduced into the enhanced smelting furnace and the stepwise reduction volatilization furnace is 0.3 MPa; The volatilization rate of each metal in the stepwise oxygen-enriched enhanced smelting volatilization section: the germanium volatilization rate reaches 98%, the indium volatilization rate can reach 97%, the gallium volatilization rate can reach 90%, the zinc volatilization rate is 98%, and the lead volatilization rate is 99%; The crude copper alloy produced in the stepped oxygen-enriched intensified smelting volatilization section is converted into crude copper after converter blowing and refining; The smelting slag produced in the stepped oxygen-enriched intensified smelting volatilization section is reduced by an electric furnace and then the ferroalloy is sold externally; The smelting fumes and dust in the stepped oxygen-enriched intensified smelting volatilization section (the flue gases of two smelting furnaces are combined together) pass through a waste heat boiler and an electrostatic precipitator, and the waste heat is recycled to produce high-temperature steam for the wet production of germanium, indium and gallium; the soot and flue gas containing germanium, gallium, indium and zinc after dust removal enter the second-stage continuous oxidation desulfurization leaching.

[0038] S2: Continuous oxidation desulfurization leaching section: S21: The soot produced in S1 is transported to the first-stage reactor through a pipeline. At the same time, waste zinc electrolyte is added to the first-stage reactor, and the mass ratio of the waste zinc electrolyte to the soot is 10:1. After sufficient stirring and pulping at normal temperature and pressure, the pulping liquid is continuously pumped into the second-stage dissolved air reactor; S22: The flue gas containing sulfur dioxide and oxygen produced in S1 is sent into the second-stage dissolved air reactor through the pipeline at the lower part of the second-stage dissolved air reactor, and the pulping liquid from the first-stage reactor is sent into the second-stage dissolved air reactor from the upper part; the flue gas is rich in high-concentration sulfur dioxide and oxygen. On the one hand, the high-temperature (160 - 250 °C) flue gas heats to maintain the temperature required for the reaction, and at the same time, the sulfur dioxide, oxygen, rare metals and waste zinc electrolyte it contains fully contact and react in the reactor; Process control of the second-stage dissolved air reactor: the reaction temperature is 105 °C - 110 °C, and the reactor pressure is 0.35 Mpa - 0.5 Mpa; S23: The liquid after the reaction in the second-stage dissolved air reactor is pumped into the first-stage gas-liquid separator. The flue gas after the first-stage gas-liquid separator is sent into the third-stage dissolved air reactor through the pipeline at the lower part of the third-stage dissolved air reactor, and the liquid after the first-stage gas-liquid separator is input into the third-stage dissolved air reactor from the upper part of the third-stage dissolved air reactor. There is an oxygen pipeline at the lower part of the third-stage dissolved air reactor, and an appropriate amount of oxygen is introduced according to needs; the unreacted sulfur dioxide, multi-metal-containing materials and oxygen in the second-stage dissolved air reactor continue to fully contact and react; Process control of the third-stage dissolved air reactor: the reaction temperature is 105 °C - 110 °C, and the reactor pressure is 0.35 Mpa - 0.5 Mpa; the final acidity of the desulfurized liquid is 0.61 mol / L, which is controlled by adding concentrated sulfuric acid to the waste electrolyte; The first-stage reactor is a titanium reactor, and the second-stage and third-stage dissolved air reactors are special alloy reactors resistant to high pressure and high temperature; The leaching rate of gallium, indium and germanium after continuous oxidation desulfurization leaching is 96 - 100%; The liquid after the third-stage dissolved air reaction is pumped into the second-stage gas-liquid separator. The flue gas after the second-stage gas-liquid separator enters an alkali spray to remove residual sulfur dioxide, and then the flue gas enters an electric demister to remove particulate matter, and the tail gas meets the discharge standards; After the liquid of the secondary gas-liquid separator passes through the slurry tank --- filter press, the filter residue is returned to the smelting process of S1; the liquid after filtration enters the third-stage rare-dispersed metal hydrometallurgical recovery section.

[0039] S3: Rare-dispersed metal hydrometallurgical recovery section: S31: The leaching solution produced by S2 is pretreated and then indium is extracted using P2O4. The indium-containing organic phase is subjected to multi-stage back-extraction with hydrochloric acid solution to obtain an indium-containing aqueous phase; the indium-containing aqueous phase is displaced with zinc plates to obtain sponge indium. The sponge indium is pressed into pellets and then melted and cast to obtain crude indium. The crude indium is electrolyzed to obtain 99.99% indium ingots; the liquid after indium displacement can be sold as zinc chloride. S32: Tannin is added to the liquid after indium extraction to precipitate germanium. ZnO is added to neutralize the pH value of the liquid to 1.8. After filtration, tannin germanium is produced; tannin germanium is oxidized and roasted at 550 °C to obtain germanium concentrate containing 22% germanium. The germanium concentrate is subjected to chlorination distillation and rectification to obtain germanium tetrachloride. Germanium tetrachloride is hydrolyzed with deionized water to produce germanium dioxide. Germanium dioxide is reduced with hydrogen to obtain metallic germanium. Finally, high-purity germanium is produced through zone melting. S33: Sodium carbonate / sodium hydroxide is added to the liquid after germanium precipitation to neutralize it to a pH value of 3.5 to obtain a hydrolysis product of Ga(OH)3. Ga(OH)3 is dissolved with HCl to obtain an HGaCl4 solution, which is combined with the residue of chlorination distillation to obtain a gallium-containing solution. TBP is used for extraction. After the loaded organic phase is back-extracted with NaOH solution, a gallium-containing aqueous phase is obtained; NaOH (180 g / L) is added to make the solution, and stainless steel is used as the cathode and stainless steel / nickel is used as the anode for electrowinning to obtain 99.99% gallium. The liquid after gallium precipitation mainly contains zinc sulfate. After secondary purification to remove impurities such as iron, manganese, cadmium, and copper, a pure zinc sulfate liquid is produced, which can be sold as a product, or used to produce zinc sulfate products and for electrowinning to produce electrolytic zinc.

[0040] Example 2: A comprehensive recovery method for low-grade multi-metal materials, the steps are as follows: S1: Stepwise oxygen-enriched enhanced smelting and volatilization section: S11: Low-grade multi-metal materials (copper 0.8%, lead 1%, zinc 3%, indium 0.01%, germanium 0.01%, gallium 0.02%, gold 5 g / t, silver 30 g / t) are mixed with 15 wt% of reducing agent pulverized coal by weight and enter the enhanced smelting furnace for smelting. The temperature in the furnace is controlled at 1150 °C, and oxygen-enriched air is blown into the high-temperature molten slag through an air duct. The oxygen-enriched concentration is 65 vt%, and the air excess coefficient is 0.85; the smelting time is 60 min. S12: The molten smelting slag enters a step-by-step reduction volatilization furnace, and after adding reducing agent pulverized coal and pyrite, the temperature is controlled at 1200°C, and oxygen-enriched air is blown into the high-temperature molten slag through an air duct, with an air excess coefficient of 0.9, to perform a step-by-step enhanced reduction volatilization smelting process; the mass ratio of smelting slag to reducing agent and pyrite is 10:1.5:2; the smelting time is 45 minutes; The enhanced smelting furnace and the step-by-step reduction volatilization furnace used in S11 and S12 are side-blown smelting furnaces; the fuel used during smelting is natural gas; the combustion-supporting gas used is pure oxygen; the oxygen content in the pure oxygen is 95vt; the pressure when the fuel gas and the combustion-supporting gas are introduced into the enhanced smelting furnace and the step-by-step reduction volatilization furnace is 0.2MPa; The crude copper alloy produced by the stepwise oxygen-enriched smelting and volatilization stage is blown and refined in a converter to produce crude copper; The smelting slag produced in the cascade oxygen-enriched smelting volatilization stage is reduced in an electric furnace and then sold as ferroalloy; The smelting dust from the cascade oxygen-enriched smelting volatilization stage (the flue gases from the two smelting furnaces are combined together) passes through the waste heat boiler and electrostatic precipitator, and the waste heat is recycled to produce high-temperature steam for the wet production of germanium, indium and gallium; the ash and flue gas containing germanium, gallium, indium and zinc produced after dust removal enter the second stage of continuous oxidation desulfurization leaching.

[0041] S2: Continuous oxidation desulfurization leaching section: S21: The fly ash produced by S1 is transported to the primary reactor through a pipeline, and waste zinc electrolyte is added to the primary reactor at a mass ratio of waste zinc electrolyte to fly ash of 10:1. After being fully stirred and slurried at room temperature and pressure, the slurry is continuously pumped into the secondary dissolved air reactor; S22: The flue gas containing sulfur dioxide and oxygen produced by S1 is sent to the secondary dissolved gas reactor from the lower pipeline of the secondary dissolved gas reactor, and the slurry liquid of the primary reactor is sent to the secondary dissolved gas reactor from the upper part; the process control of the secondary dissolved gas reactor: the reaction temperature is 105℃~110℃, and the reactor pressure is 0.35Mpa~0.5Mpa; S23: The liquid after the reaction in the secondary dissolved gas reactor is pumped into the primary gas-liquid separator, and the flue gas after the primary gas-liquid separator is sent to the third-stage dissolved gas reactor from the middle and lower pipeline of the third-stage dissolved gas reactor. The liquid after the primary gas-liquid separator is input into the third-stage dissolved gas reactor from the upper part of the third-stage dissolved gas reactor. There is an oxygen pipeline at the lower part of the third-stage dissolved gas reactor, and an appropriate amount of oxygen is introduced according to the needs; process control of the third-stage dissolved gas reactor: reaction temperature 105℃~110℃, reactor pressure 0.35Mpa~0.5Mpa; final acidity of desulfurized liquid is 0.56mol / L, which is controlled by adding concentrated sulfuric acid to the waste electrolyte; The primary reactor is a titanium reactor, and the secondary and tertiary dissolved gas reactors are high-pressure and high-temperature resistant special alloy reactors; The liquid after the three-stage dissolved air reaction is pumped into the secondary gas-liquid separator. After passing through the secondary gas-liquid separator, the flue gas enters the caustic spray to remove residual sulfur dioxide, and then enters the electrostatic demister to remove particulate matter. The tail gas is discharged up to the standard. The liquid from the secondary gas-liquid separator passes through the slurry tank --- filter press. The filter residue is returned to the smelting process of S1; the liquid after filtration enters the third stage of the recovery section for rare-dispersed metals by hydrometallurgy.

[0042] S3: Recovery section for rare-dispersed metals by hydrometallurgy: S31: After the leaching solution produced by S2 is pretreated, indium is extracted using P2O4. The indium-containing organic phase is subjected to multi-stage back-extraction with hydrochloric acid solution to obtain an indium-containing aqueous phase; the indium-containing aqueous phase is displaced with zinc plates to obtain sponge indium. The sponge indium is pressed into pellets and melted and cast to obtain crude indium. The crude indium is electrolyzed to obtain 99.99% indium ingots; the liquid after indium displacement can be sold as zinc chloride. S32: Tannin is added to the liquid after indium extraction to precipitate germanium. ZnO is added to neutralize the pH value of the liquid to 1.2. After filtration, tannin germanium is produced; tannin germanium is oxidized and roasted at 500 °C to obtain germanium concentrate containing 15% germanium. The germanium concentrate is subjected to chlorination distillation and rectification to obtain germanium tetrachloride. Germanium tetrachloride is hydrolyzed with deionized water to produce germanium dioxide. Germanium dioxide is reduced with hydrogen to obtain metallic germanium. Finally, high-purity germanium is produced through zone melting. S33: After the germanium precipitation liquid is neutralized with NaCO3 / NaOH to a pH value of 3.1, the hydrolysis product Ga(OH)3 is obtained. Ga(OH)3 is dissolved with HCl to obtain an HGaCl4 solution, which is combined with the chlorination distillation residue liquid to obtain a gallium-containing solution. TBP extraction is used. After the loaded organic phase is back-extracted with NaOH solution, a gallium-containing aqueous phase is obtained; NaOH (150 g / L) is added to make the solution. Using stainless steel as the cathode and stainless steel / nickel as the anode, electrolysis is carried out to obtain 99.99% gallium. The liquid after gallium precipitation mainly contains zinc sulfate. After secondary purification to remove impurities such as iron, manganese, cadmium, and copper, a pure zinc sulfate liquid is produced, which can be sold as a product, or used to produce zinc sulfate products and electrolytically produce zinc.

[0043] Example 3: A comprehensive recovery method for low-grade multi-metal materials, the steps are as follows: S1: Gradient oxygen-enriched enhanced smelting and volatilization section: S11: Low-grade multi-metal materials (copper 8%, lead 3%, zinc 6%, indium 0.1%, germanium 0.3%, gallium 0.15%, gold 15 g / t, silver 50 g / t) are mixed with 25 wt% of the reducing agent pulverized coal by weight and enter the enhanced smelting furnace for smelting. The temperature in the furnace is controlled at 1300 °C. Oxygen-enriched air is blown into the high-temperature molten slag through the air duct, with an oxygen-enriched concentration of 65 vt% and an air excess coefficient of 1.0; the smelting time is 100 min. S12: The molten smelting slag enters the cascade reduction and volatilization furnace. After adding the reducing agent pulverized coal and pyrite, the temperature is controlled at 1350 °C. Oxygen-enriched air is blown into the high-temperature molten slag through an air duct with an air excess coefficient of 0.65 to conduct the cascade enhanced reduction and volatilization smelting process; the mass ratio of the smelting slag, reducing agent, and pyrite is 10:5:1; the smelting time is 100 min; The enhanced smelting furnace and cascade reduction and volatilization furnace used in S11 and S12 are side-blowing smelting furnaces; the fuel used for smelting is natural gas; the combustion-supporting gas used is pure oxygen; the oxygen content in the pure oxygen is 95 vt%; the pressure when fuel gas and combustion-supporting gas are introduced into the enhanced smelting furnace and cascade reduction and volatilization furnace is 0.4 MPa; The crude copper alloy produced in the cascade oxygen-enriched enhanced smelting and volatilization section is blown and refined in a converter to produce crude copper; The smelting slag produced in the cascade oxygen-enriched enhanced smelting and volatilization section is reduced in an electric furnace and then the ferroalloy is sold externally; The smelting soot in the cascade oxygen-enriched enhanced smelting and volatilization section (the flue gases of the two smelting furnaces are combined together) passes through a waste heat boiler and an electrostatic precipitator, and the waste heat is recovered to produce high-temperature steam for the hydrometallurgical production of germanium, indium, and gallium; the soot and flue gas containing germanium, gallium, indium, and zinc after dust removal enter the second-stage continuous oxidation and desulfurization leaching.

[0044] S2: Continuous oxidation and desulfurization leaching section: S21: The soot produced in S1 is transported to the first-stage reactor through a pipeline. At the same time, waste zinc electrolyte is added to the first-stage reactor. The mass ratio of the waste zinc electrolyte to the soot is 10:1. After sufficient stirring and pulping at normal temperature and pressure, the pulping liquid is continuously pumped into the second-stage dissolved air reactor; S22: The flue gas containing sulfur dioxide and oxygen produced in S1 is fed into the second-stage dissolved air reactor through the lower pipeline of the second-stage dissolved air reactor, and the pulping liquid from the first-stage reactor is fed into the second-stage dissolved air reactor from the upper part; Process control of the second-stage dissolved air reactor: The reaction temperature is 105 °C to 110 °C, and the reactor pressure is 0.35 Mpa to 0.5 Mpa; S23: The liquid after reaction in the second-stage dissolved air reactor is pumped into the first-stage gas-liquid separator. The flue gas after the first-stage gas-liquid separator is fed into the third-stage dissolved air reactor through the lower pipeline of the third-stage dissolved air reactor, and the liquid after the first-stage gas-liquid separator is input into the third-stage dissolved air reactor from the upper part of the third-stage dissolved air reactor. There is an oxygen pipeline at the lower part of the third-stage dissolved air reactor, and an appropriate amount of oxygen is introduced as needed; Process control of the third-stage dissolved air reactor: The reaction temperature is 105 °C to 110 °C, and the reactor pressure is 0.35 Mpa to 0.5 Mpa; The final acidity of the desulfurization liquid is 0.56 mol / L, which is controlled by adding concentrated sulfuric acid to the waste electrolyte; The first-stage reactor is a titanium reactor, and the second-stage and third-stage dissolved air reactors are special alloy reactors resistant to high pressure and high temperature; The liquid after the three - stage dissolved air reaction is pumped into the secondary gas - liquid separator. After passing through the secondary gas - liquid separator, the flue gas enters the alkali spray to remove residual sulfur dioxide, and then enters the electric demister to remove particulate matter, and the tail gas is discharged up to the standard; The liquid of the secondary gas - liquid separator passes through the slurry tank --- filter press. The filter residue is returned to the smelting process of S1; the liquid after filtration enters the third - stage rare - dispersed metal hydrometallurgical recovery section.

[0045] S3: Rare - dispersed metal hydrometallurgical recovery section: S31: The leachate produced by S2 is pretreated and indium is extracted using P2O4. The indium - containing organic phase is subjected to multi - stage back - extraction with hydrochloric acid solution to obtain an indium - containing aqueous phase; the indium - containing aqueous phase is displaced with zinc plates to obtain sponge indium. The sponge indium is pressed into pellets and then melted and cast to obtain crude indium. The crude indium is electrolyzed to obtain 99.99% indium ingots; the liquid after indium displacement can be sold as zinc chloride; S32: After indium extraction, tannin is added to the liquid to precipitate germanium, ZnO is added to neutralize the pH value of the liquid to 1.9, and tannin germanium is produced after filtration; tannin germanium is oxidized and roasted at 600 °C to obtain germanium concentrate containing 25% germanium. The germanium concentrate is subjected to chlorination distillation and rectification to obtain germanium tetrachloride. Germanium tetrachloride is hydrolyzed with deionized water to produce germanium dioxide, and germanium dioxide is reduced with hydrogen to obtain metallic germanium. Finally, high - purity germanium is produced through zone melting; S33: After germanium precipitation, the liquid is neutralized with NaCO3 / NaOH to a pH value of 4.0 to obtain a hydrolysis product Ga(OH)3. Ga(OH)3 is dissolved with HCl to obtain an HGaCl4 solution, which is combined with the chlorination distillation residue to obtain a gallium - containing solution. TBP extraction is used. After the loaded organic phase is back - extracted with NaOH solution, a gallium - containing aqueous phase is obtained; NaOH (200 g / L) is added to make the solution, stainless steel is used as the cathode, and stainless steel / nickel is used as the anode for electrowinning to obtain 99.99% gallium; The liquid after gallium precipitation mainly contains zinc sulfate. After secondary purification to remove impurities such as iron, manganese, cadmium, and copper, a pure zinc sulfate liquid is produced, which can be sold as a product, or used to produce zinc sulfate products and for electrowinning to produce electrolytic zinc.

[0046] Compared with the prior art, the present invention has the following positive and beneficial effects: The present invention adopts the stepped oxygen - enriched intensifying smelting method to step - by - step enrich and recover zinc, lead, germanium, indium, gallium, etc. in germanium - containing materials; compared with the traditional rotary kiln volatilization and fuming volatilization methods, the volatilization rate of rare - dispersed metals is high. The indium volatilization rate can reach more than 98%, the germanium volatilization rate can reach more than 96%, and the gallium volatilization rate can reach more than 95%.

[0047] The present invention adopts the stepped oxygen - enriched intensifying smelting method, which improves the smelting efficiency, reduces the flue gas volume during the smelting process, and increases the sulfur dioxide concentration in the soot. The sulfur dioxide concentration in the soot can reach 3% (the sulfur dioxide concentration in the flue gas of the traditional volatilization method is low and unstable), providing favorable conditions for the next direct continuous oxidative desulfurization leaching reaction.

[0048] The stepped oxygen-enriched intensifying smelting furnace type adopted in the present invention is a two-stage side-blown furnace, which is different from the traditional rotary kiln and fuming furnace.

[0049] The present invention adopts the direct continuous oxidation desulfurization technology, in which the germanium-containing rare and dispersed metal soot in the soot, sulfur dioxide and oxygen in the flue gas directly react with the waste dilute acid; this process shortens the soot disposal process, omits the processes such as surface cooler, electrostatic precipitator, purification, absorption, etc. in the traditional flue gas treatment, greatly reduces the huge disposal equipment, disposal site and disposal cost of the traditional sulfur-containing soot; realizes the direct resource utilization of sulfur dioxide, and avoids the secondary pollution of solid waste; and has good economic benefits.

[0050] The equipment in the continuous oxidation desulfurization section of the present invention is a three-stage highly efficient intensifying desulfurization reactor, and this process equipment has the dual functions of a desulfurization reactor and a wet leaching reactor, realizing the highly efficient intensifying metallurgy technology for rare and dispersed metals; The present invention synergistically couples the stepped oxygen-enriched intensifying smelting method, the direct continuous oxidation desulfurization technology and the comprehensive recovery method for rare and dispersed metals, realizing the comprehensive recovery and utilization technology for multiple metals such as zinc, germanium, indium, gallium, etc. in low-grade germanium materials; conforms to the concept of green and low-carbon development and the concept of comprehensive utilization of renewable resources, and has remarkable social benefits.

Claims

1. A comprehensive recovery method for low-grade multi-metal materials, characterized in that the steps Including: (1) Low-grade polymetallic materials enter the intensifying smelting furnace, and a reducing agent is added for smelting; (2) The smelting slag enters the stepwise reduction and volatilization furnace, and a reducing agent and pyrite are added for smelting. The obtained smelting slag is processed to produce ferroalloy; the obtained crude copper alloy is processed to produce crude copper; (3) The soot and waste zinc electrolyte obtained from smelting are mixed to obtain a pulping liquid; (4) The flue gas obtained from smelting contacts and reacts with the pulping liquid, and the reacted liquid is subjected to gas-liquid separation; (5) The flue gas and liquid obtained after gas-liquid separation contact and react again; (6) The indium is extracted from the leaching solution obtained in step (5) using P2O4; (7) Germanium is precipitated by adding tannin to the liquid after indium extraction; (8) An alkali solution is added to the solution after germanium precipitation to neutralize and recover gallium.

2. The comprehensive recovery method of low-grade multi-metal materials according to claim 1, characterized in that, In step (1), the addition amount of the reducing agent is 15% - 25% of the material weight, and the temperature in the intensifying smelting furnace is controlled at 1150°C - 1300°C; oxygen-enriched air is blown into the high-temperature molten slag, with the oxygen-enriched concentration of 60% - 70% vt and the air excess coefficient of 0.85 - 1.0; the smelting time is 60 - 100 min.

3. The comprehensive recovery method of low-grade polymetallic materials according to claim 1, characterized in that, In step (2), the mass ratio of the smelting slag to the reducing agent and pyrite is 10:1.5 - 5:1 - 2; the temperature is controlled at 1200°C - 1350°C; oxygen-enriched air is blown into the high-temperature molten slag, with the oxygen-enriched concentration of 60% - 70% vt and the air excess coefficient of 0.65 - 0.90; the smelting time is 45 - 100 min.

4. The comprehensive recovery method of low-grade polymetallic materials according to claim 1 or 2 or 3, characterized in that, The reducing agent described in steps (1) and (2) is pulverized coal or coke; the intensifying smelting furnace and the stepwise reduction and volatilization furnace are bottom-blown smelting furnaces or side-blown smelting furnaces; the fuel used for smelting is one or more of natural gas, coal gas, and pulverized coal; the combustion-supporting gas used is pure oxygen; the oxygen content in the pure oxygen is 70% - 100% vt; the pressure when fuel gas and combustion-supporting gas are introduced into the intensifying smelting furnace and the stepwise reduction and volatilization furnace is 0.2 - 0.4 MPa.

5. The comprehensive recovery method of low-grade polymetallic materials according to claim 1, characterized in that, In step (3), the mass ratio of the soot to the waste zinc electrolyte is 1:8 - 12.

6. The comprehensive recovery method of low-grade multi-metal materials according to claim 1, characterized in that, In steps (4) and (5), the reaction temperature during the contact reaction is 105°C - 110°C, and the reactor pressure is 0.35 MPa - 0.5 MPa; the final acidity of the desulfurization liquid obtained in step (5) is 0.55 - 0.65 mol / L, and the acidity is controlled by adding concentrated sulfuric acid to the waste zinc electrolyte.

7. The comprehensive recovery method of low-grade polymetallic materials according to claim 1 or 6, characterized in that, Oxygen is introduced during the contact reaction in step (5).

8. The comprehensive recovery method of low-grade multi-metal materials according to claim 1, characterized in that, In step (6), the indium-containing organic phase obtained by indium extraction is subjected to multi-stage back-extraction with hydrochloric acid solution to obtain an indium-containing aqueous phase; the indium-containing aqueous phase is displaced with a zinc plate to obtain sponge indium, the sponge indium is pelletized and melted to obtain crude indium, and the crude indium is electrolyzed to obtain indium ingots with a purity of 99.99%.

9. The comprehensive recovery method of low-grade polymetallic materials according to claim 1, characterized in that, In step (7), after adding tannin to precipitate germanium, ZnO is added to neutralize the pH value of the liquid to 1.2 - 2.0, and tannin germanium is produced after filtration; tannin germanium is oxidized and roasted at 500°C - 600°C to obtain germanium concentrate containing 15% - 25% wt of germanium. The germanium concentrate is subjected to chlorination distillation and rectification to obtain germanium tetrachloride. Germanium tetrachloride is hydrolyzed with deionized water to produce germanium dioxide, and germanium dioxide is reduced with hydrogen to obtain metallic germanium, and finally high-purity germanium is produced through zone melting.

10. The comprehensive recovery method for low-grade polymetallic materials according to claim 1, characterized in that The lye described in step (8) is a mixed solution of NaCO3 and NaOH. The lye is added to neutralize until the pH value of the solution is 3-4 to obtain the hydrolysis product Ga(OH)3. Ga(OH)3 is dissolved with HCl to obtain an HGaCl4 solution, which is combined with the chlorination distillation residue to obtain a gallium-containing solution. The solution is extracted with TBP. After the loaded organic phase is back-extracted with a NaOH solution, an aqueous gallium-containing phase is obtained. NaOH is added to prepare the solution, and the addition amount is 150-200 g / L. Stainless steel is used as the cathode, and stainless steel / nickel is used as the anode. Gallium with a purity of 99.99% is obtained by electrowinning.

Images