Method for selectively and efficiently volatilizing germanium-containing material to recover germanium

Abstract

The invention discloses a method for selectively and efficiently volatilizing and recovering germanium from a germanium-containing material. The method comprises the following steps: mixing a dried germanium-containing material with a carbonaceous reducing agent and a binder, uniformly mixing, briquetting, and drying to obtain a block mass material with the sulfur content of 4.5-14wt%; adding the obtained dried block mass material into a reaction device, carrying out carbon thermal reduction sulfuration volatilization at the temperature of 880-950 DEG C, and reacting for at least 30 minutes; and smoke dust rich in valuable metals such as germanium and the like and reduced slag are obtained. The volatilization rate of germanium is larger than 99%, and the volatilization rate of lead and zinc is smaller than 10%. The method solves the problems of long process flow, large germanium dispersion loss, taking away a large amount of germanium by the water-quenched slag of the fuming furnace, low germanium recovery rate and the like when the germanium-containing material enters a lead pyrometallurgy system for treatment, and has better economic, social and environmental benefits.

Description

Technical Field

[0001] The present invention belongs to the field of comprehensive utilization of secondary resources in lead-zinc smelting, and particularly relates to a method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials. Background Art

[0002] Germanium is an important strategic metal, known as the "king of new materials", and is one of the key basic materials in the fields of optical fiber communication, solar cells, infrared optical devices, etc. The world's proven germanium reserves are about 8,600 tons. In nature, germanium is difficult to form an independent ore deposit. It mainly enters the mineral lattice in the form of isomorphism or exists in organic matter in the form of adsorption, with geochemical characteristics such as affinity for silicon, iron, sulfur, and organic matter, and is often associated with lead-zinc ore and coal mine. The lead-zinc smelting process is the main source of germanium extraction, and about 51.7% of germanium is recovered from zinc leaching residues. The conventional wet zinc smelting process is flash roasting - leaching - purification - electrowinning. About 94% of germanium enters the zinc leaching residue. The zinc leaching residue is fumed and volatilized to obtain germanium-rich secondary zinc oxide powder. After multi-stage leaching, germanium is recovered from the solution, and the leaching residue is lead slag (germanium content is 300 - 1500 g / t). The lead slag contains a large amount of germanium and is a valuable secondary germanium resource.

[0003] The main treatment method for germanium-containing materials in industry is to enter the lead pyrometallurgical system by mixing with lead concentrate, and its main process flow is oxygen-enriched smelting - reduction smelting - fuming volatilization. Under the oxidizing atmosphere during the oxygen-enriched smelting process, germanium exists in the slag in the form of combined GeO2; during the reduction smelting process, a small amount of germanium is reduced and volatilized in the form of GeO into the reduction smelting dust; most of the germanium is reduced and volatilized into the dust during the treatment process in the fuming furnace, and the germanium-containing dust is used as the raw material for wet extraction of germanium. However, in the lead pyrometallurgical treatment process of germanium-containing materials, there are problems such as germanium dispersion loss, large amount of water-quenched slag produced by the fuming furnace, and large germanium loss (the germanium content in the water-quenched slag is 20 - 35 g / t), and the germanium volatilization recovery rate is about 85%. In order to achieve the efficient recovery of Zn, Pb, and Ge in lead slag, researchers have proposed acid leaching and alkaline leaching processes to separately treat germanium-containing materials. Sulfuric acid leaching is the most commonly used acid leaching process. This process can only achieve the leaching of Zn and Ge, and Pb still exists in the form of lead sulfate and cannot achieve the synchronous leaching of Pb, Zn, and Ge. The leaching residue needs to enter the lead smelting system for treatment; moreover, due to the encapsulation of lead sulfate, the germanium leaching rate is low (less than 50%). Under alkaline leaching conditions, the synchronous leaching of Pb, Zn, and Ge in germanium-containing materials cannot be achieved either, and the leaching residue needs to be further treated to recover zinc and lead; moreover, due to the formation of Pb(OH)2 colloid, which adsorbs germanium, the germanium leaching rate is relatively low (less than 70%). Therefore, there are still many deficiencies in the existing wet extraction methods for separately treating germanium-containing materials. For example, it is difficult to achieve the synchronous and efficient leaching of Pb, Zn, and Ge, the germanium leaching recovery rate is relatively low, the reagent consumption is large, and the burden of waste liquid treatment is heavy. Therefore, how to achieve the efficient recovery of germanium in germanium-containing materials produced in the process of zinc hydrometallurgy is an important research direction.

[0004] In order to overcome the above problems, based on the principle that germanium metal and its oxides are easily sulfidized and transformed under medium and low temperature conditions, and utilizing the characteristic of relatively high sulfur content in lead slag, the present invention has developed a method of medium and low temperature carbothermal reduction - sulfidization volatilization. Under the carbothermal reduction system, germanium high-valent oxides are reduced to low-valent oxides or germanium metal, and under a relatively high sulfur potential, germanium metal and its low-valent oxides are sulfidized and transformed into easily volatile GeS; under medium and low temperature carbothermal reduction conditions, Pb and Zn are basically not volatilized, thus achieving the selective and efficient volatilization of germanium from lead and zinc. The reduced slag containing zinc and lead enters the lead smelting system to further extract lead and zinc. This method realizes the efficient and selective volatilization of germanium in germanium-containing materials, can directly obtain germanium concentrate, avoids processes such as multi-stage leaching - precipitation to produce germanium concentrate from germanium-containing zinc oxide dust, and also avoids a large amount of germanium loss caused by the water-quenched slag when germanium-containing materials enter the lead pyrometallurgical system, which is beneficial to reducing costs, simplifying the process, and increasing the germanium recovery rate. Summary of the Invention

[0005] To solve the above problems of the prior art, the present invention provides a method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials, breaking through the limitation that germanium is mainly volatilized in the form of GeO during the carbothermal reduction process of traditional germanium-containing materials. Under medium and low temperature carbothermal reduction conditions, germanium is transformed into GeS which is more easily volatilized, changing the mode that germanium is mainly volatilized in the form of GeO during the traditional carbothermal reduction process to the mode that germanium is mainly volatilized in the form of GeS during the carbothermal reduction-sulfide volatilization process, while lead and zinc are basically not volatilized, thereby realizing the selective volatilization of germanium from lead and zinc. This method can at least to a certain extent solve the problems in the prior art such as low recovery rate of germanium in germanium-containing materials and large dispersion loss of germanium, and realize the efficient and selective volatilization and recovery of germanium; at the same time, the reduced slag obtained by the medium and low temperature carbothermal reduction-sulfide volatilization process can be used as the raw material for the lead pyrometallurgy process, and has no influence on the process of extracting lead and zinc in the lead smelting system, and no waste slag and waste water are generated.

[0006] To achieve the above object, the main technical solutions adopted by the present invention are as follows:

[0007] A method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials, comprising the following steps:

[0008] Step 1

[0009] Mix and proportion the dried germanium-containing material with a carbonaceous reducing agent and a binder. After mixing evenly, pelletize and dry to obtain a pellet material with a sulfur content of 4.5 - 14 wt%; wherein the dosage of the carbonaceous reducing agent is 2 - 5% of the weight of the germanium-containing material; the dosage of the binder is 1 - 3% of the weight of the germanium-containing material;

[0010] Step 2

[0011] Add the dried pellet material obtained in Step 1 into a reaction device, and carry out carbothermal reduction-sulfide volatilization at a temperature of 880 - 950 °C for at least 30 min; obtain soot rich in valuable metals such as germanium and reduced slag.

[0012] Preferably, in Step 1, for the method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials of the present invention, the germanium-containing material is the germanium-containing slag produced in the zinc hydrometallurgy process, and the germanium-containing slag contains 5 - 15 wt% of S. In actual application, the germanium-containing slag produced in the zinc hydrometallurgy process generally also contains lead and zinc, etc.

[0013] As a further preference, the germanium-containing slag produced in the zinc hydrometallurgy process includes at least one of germanium-containing neutralization slag or germanium-containing leaching slag.

[0014] Preferably, in Step 1, for the method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials of the present invention, in the germanium-containing material, the content of Zn is 5 - 15 wt%, the content of Pb is 5 - 35 wt%, the content of S is 5 - 15 wt%, and the content of Ge is 200 - 5000 g / t.

[0015] In the present invention, the germanium-containing material is fully and uniformly mixed with a carbonaceous reducing agent and a binder to obtain a mixture containing a certain amount of S and Ge, creating good kinetic conditions for the subsequent carbothermal reduction-sulfurization volatilization process; meanwhile, a lump material with a certain strength and a certain particle size is prepared to prevent a large amount of fine particles from entering the soot with the airflow during the carbothermal reduction-sulfurization volatilization process and reducing the germanium grade in the soot, so as to directly obtain germanium concentrate with a high germanium content (germanium content greater than 1.5 wt%). Compared with GeO₂, GeO is more easily sulfidized to GeS. The purpose of adding the carbonaceous reducing agent is to reduce free GeO₂ to GeO, and at the same time reduce and decompose the combined GeO₂ (such as germanium combined with CaO and SiO₂, and germanium combined with lead, zinc, and iron oxides), release GeO₂, and reduce it to GeO.

[0016] Step 2 is mainly carbothermal reduction-sulfurization volatilization; the specific operation is as follows:

[0017] The dried lump material obtained in Step 1 is added to a reaction device, and carbothermal reduction-sulfurization volatilization is carried out at a temperature of 880-950 °C, preferably 900-920 °C, for a reaction time of 30-60 min. Soot rich in valuable metals such as germanium and reduced slag are obtained. The reactions involved in the carbothermal reduction-sulfurization volatilization process are shown in the following formulas (1)-(10).

[0018] GeO₂ + 2C = Ge + 2CO(g) (1)

[0019] GeO₂ + 2CO(g) = Ge + 2CO₂(g) (2)

[0020] GeO₂ + C = GeO(g) + CO(g) (3)

[0021] GeO₂ + CO(g) = GeO(g) + CO₂(g) (4)

[0022] GeO₂ + 4C + SO₂(g) = GeS(g) + 4CO(g) (5)

[0023] GeO₂ + 4CO(g) + SO₂(g) = GeS(g) + 4CO₂(g) (6)

[0024] GeO(g) + 3C + SO₂(g) = GeS(g) + 3CO(g) (7)

[0025] GeO(g) + 3CO(g) + SO₂(g) = GeS(g) + 3CO₂(g) (8)

[0026] Ge + 2C + SO2(g) = GeS(g) + 2CO(g) (9)

[0027] Ge + 2CO(g) + SO2(g) = GeS(g) + 2CO2(g) (10)

[0028] When there is no sulfur or the sulfur content is low in the reaction system, the main reactions occurring in the carbothermal reduction process are shown in equations (1)-(4). The relationship between the reaction -T is as shown in Appendix Figure 2 (a). As can be seen from Appendix Figure 2 (a), the initial reaction temperature for the reduction of GeO2 by C is relatively low. The initial reaction temperature of equation (1) is 700 °C, and that of equation (2) is 900 °C. However, the solid - solid reaction is restricted by the limited contact area, and the effect of this type of reaction on the reduction and volatilization of germanium is very low. In fact, the carbothermal reduction of metal oxides mainly depends on the indirect reduction by CO, that is, reaction equations (2) and (4). However, in the actual carbothermal reduction process, reaction equation (2) is very difficult to occur. Therefore, the reduction and volatilization of germanium mainly proceed through reaction equation (4) (i.e., germanium oxide is reduced to GeO and volatilized by CO), and the initial reaction temperature of reaction (4) is relatively high, being 1100 °C. Increasing the temperature (increasing the reducing atmosphere) is beneficial to the reduction and volatilization of germanium. This is the reason why the carbothermal reduction temperature of germanium - containing materials in industry generally needs to be controlled above 1150 °C. For example, the process temperature of the rotary kiln is generally 1150 - 1200 °C, and that of the fuming furnace is 1200 - 1300 °C. However, when there is excessive sulfur in the reaction system (as shown in Appendix Figure 2 (b)), the initial reaction temperature for the reduction - sulfidation of germanium oxide decreases significantly. For example, the initial reaction temperature of reaction equation (5) is only 500 °C, and the initial reaction temperatures of other reactions (equations (6)-(10)) are even lower. This indicates that when there is excessive sulfur in the reaction system, metallic germanium and its oxides are easily reduced - sulfidated and converted into easily volatile GeS. Lead sulfate starts to decompose at around 850 °C, and the SO2 generated by the decomposition provides a sulfur source for the sulfidation conversion of metallic germanium and its oxides. Moreover, the diffusion of SO2 gas in the pellets creates good contact conditions for the sulfidation conversion reaction.

[0029] Among them, in the above - mentioned step (1), the carbonaceous reducing agent is one or a mixture of two of anthracite, lignite, and coke; the particle size of the reducing agent is less than 50 μm. The binder is one or a mixture of two of bentonite, lime, and organic binders.

[0030] In the present invention, the organic binder is selected from at least one of carboxymethyl cellulose, carboxymethyl cellulose salts, and synthetic resins. In practical applications, the main components of the organic binder are three elements, C, H, and O, and the sum of the contents of these three elements is greater than 90 wt%.

[0031] In the present invention, common pellet binders can also be used in the present invention.

[0032] Among them, in the medium and low temperature carbothermal reduction-sulfurization volatilization process described in the above step (2), the volatilization rates of zinc and lead are less than 10%, and the volatilization rate of germanium is greater than 99%; the main chemical components of the soot are as follows: Pb 30 - 60 wt%, Zn 10 - 40 wt%, Ge 1.5 - 5 wt%, S 5 - 10 wt%, and the contents of other impurity components, such as Fe, As, SiO2, CaO, MgO, and Al2O3, are less than 0.2 wt%.

[0033] After optimization, the content of Ge in the soot is greater than or equal to 1.55 wt%.

[0034] Beneficial effects

[0035] In this method, the germanium-containing material is mixed evenly with a carbonaceous reducing agent and a binder to form pellets. Under the conditions of medium and low temperature carbothermal reduction and the presence of excess sulfur, the metals Ge, GeO, and GeO2 are sulfidized and converted into GeS, which is more volatile. Under the conditions of medium and low temperature carbothermal reduction-sulfurization volatilization, the volatilization rates of Pb and Zn are low (less than 10%), while the volatilization rate of Ge can reach more than 99%, realizing the selective volatilization of Ge from the germanium-containing material with Pb and Zn; the reduced slag after medium and low temperature carbothermal reduction-sulfurization volatilization is sent to the pyrometallurgical lead-smelting system to recover Pb and Zn. This method realizes the selective volatilization and recovery of Ge with Pb and Zn, can obtain germanium concentrate with a high germanium content, and the germanium concentrate can be directly used in the subsequent germanium extraction process of chlorination distillation, avoiding the dispersion loss of germanium-containing materials entering the pyrometallurgical lead-smelting system, simplifying the germanium extraction process, and no waste slag and wastewater are generated in the whole process. Compared with the existing technologies and methods, it has the following remarkable effects:

[0036] (1) It is beneficial to improve the germanium recovery rate. This method avoids the germanium dispersion loss caused by the traditional germanium-containing materials entering the lead pyrometallurgical system (such as oxygen-enriched smelting-side blowing reduction-fuming furnace volatilization), and also avoids the loss of germanium carried by a large amount of water-quenched slag (the germanium content in the water-quenched slag is 20 - 35 g / t), which is beneficial to improving the germanium recovery rate. The germanium volatilization recovery rate is increased from about 85% in the existing industrial practice to 99%, an increase of about 14%; the germanium content in the fuming furnace water-quenched slag is reduced from 20 - 35 g / t to less than 10 g / t.

[0037] (2) It is conducive to simplifying the process and directly obtaining high-grade germanium concentrate. By taking advantage of the characteristics that metallic germanium and its oxides are easily sulfidized and transformed and the high sulfur content in germanium-containing materials, under the conditions of medium-low temperature (880~950 °C) carbothermal reduction-sulfidation, germanium compounds are transformed into GeS that is easy to volatilize (GeS is more volatile than GeO), while Pb and Zn are basically non-volatile; the volatilization rate of Ge is over 99%, and the volatilization rates of Pb and Zn are less than 10%; germanium concentrate containing 1.5~5 wt% of germanium is obtained, which can be directly used as the raw material for extracting germanium by chlorination distillation. In the existing industrial practice, after germanium-containing materials are volatilized through oxygen-enriched smelting-side blowing reduction-fuming furnace, the germanium content in the obtained germanium-containing soot is generally 0.1~0.2 wt%, and methods such as leaching-precipitation are still needed to obtain germanium concentrate containing 2~3 wt% of germanium.

[0038] (3) It can be seamlessly connected with the process of recovering Pb, Zn, and Ge in the existing lead pyrometallurgy system. The reduced slag after medium-low temperature carbothermal reduction-sulfidation volatilization can be sent to the lead smelting system to further recover Pb and Zn, and it has no impact on the subsequent recovery of Pb and Zn. By adding a separate process of carbothermal reduction-sulfidation volatilization for recovering germanium at the front end of sending germanium-containing materials to the lead smelting system, it can be seamlessly connected with the process of recovering Pb, Zn, and Ge in the existing lead smelting system. The present invention also realizes the efficient separation of Ge from a large amount of Pb and Zn. Description of the Drawings

[0039] Figure 1 is the process flow of the present invention.

[0040] Figure 2 is the reaction of germanium oxide in the carbon reduction system and the carbon + sulfur co-existing reduction system -T diagram.

[0041] From Figure 1 it can be seen the basic process of the present invention.

[0042] Figure 2 In, (a) is the -T diagram of the reaction in the carbon reduction system; (b) is the -T diagram of the reaction in the carbon + sulfur co-existing system; From Figure 2 it can be seen that when there is no S in the reaction system (or the S content is low), the temperature required for GeO2 to be reduced by C to GeO and volatilize is high, usually higher than 1100 °C; while when there is a certain amount of S and C in the reaction system, the starting reaction temperature for Ge to be reduced and sulfidized is significantly reduced to below 500 °C. This shows that the presence of S in the reaction system is conducive to the volatilization of Ge in the form of GeS; at the same time, Pb and Zn are basically non-volatile at a lower temperature. In the thermodynamic diagram (such as Figure 2b) When S exists in the reaction system, the starting reaction temperature is relatively low, below 500 °C; however, during the actual exploration process, it was found that in the carbothermal reduction-sulfidation process of germanium-containing materials, the source of sulfur is SO2 generated by the decomposition of PbSO4, and PbSO4 starts to decompose at 850 °C. Detailed implementation mode

[0043] The following describes a method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials involved in the present invention through specific examples, rather than limiting the present invention.

[0044] Comparative example 1:

[0045] In this example, the germanium-containing material contains 5.32 wt% Zn, 34.89 wt% Pb, 12.36 wt% S, and 202.21 g / t Ge.

[0046] First, under the conditions of introducing oxygen (flow rate 5 L / min), temperature 1150 °C, and reaction for 60 min, the germanium-containing material is subjected to oxidative roasting and desulfurization. The sulfur content in the roasting product is 2.09 wt.%, and the volatilization rate of germanium during the roasting and desulfurization process is only 2.79%. Then, the roasted and desulfurized product is operated according to the following steps. After carbothermal reduction-sulfidation volatilization, the volatilization rate of germanium is not high, indicating that a higher S content in the reaction system is beneficial to the sulfidation volatilization of germanium; specifically as follows:

[0047] (1) Material preparation

[0048] Batching: After the roasted and desulfurized product is crushed and ground, it is mixed with a carbonaceous reducing agent and a binder for batching. After mixing evenly, a base material is obtained; the reducing agent is anthracite, and the carbon ratio is 3 wt% of the weight of the germanium-containing material, and its particle size is less than 50 μm; the binder is an organic binder (the organic binder is composed of sodium carboxymethylcellulose and synthetic resin, mainly composed of three elements C, H, and O, and the sum of the contents of these three elements is greater than 90 wt%), and its dosage is 2 wt% of the weight of the germanium-containing material.

[0049] Pelletizing: The base material is pelletized to obtain pelletized materials with certain strength and certain particle size.

[0050] Drying: The pelletized materials are dried (the drying temperature is 105 °C and the time is 480 min). The particle size of the pelletized materials obtained after drying is 8 - 30 mm.

[0051] (2) Carbothermal reduction-sulfidation volatilization

[0052] The dried pelletized materials obtained in step (1) are added to the reaction device, and carbothermal reduction-sulfidation volatilization is carried out at a temperature of 1000 °C for 60 min. Smoke and dust rich in valuable metals such as germanium and reduced slag are obtained.

[0053] After detection, the germanium volatilization rate is 35.5%, the lead volatilization rate is less than 5%, and the zinc volatilization rate is less than 10%; the main chemical components of the soot are as follows: Pb 61.12wt%, Zn 12.24wt%, Ge 0.59wt%, S 3.45wt%, and other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3, etc., the content is less than 0.2%.

[0054] Example 1:

[0055] In this example, the germanium-containing material contains Zn 5.32wt%, Pb 34.89wt%, S 12.36wt%, Ge 202.21g / t;

[0056] The specific implementation steps are as follows:

[0057] (1) Material preparation

[0058] Batching: Mix the dried germanium-containing material with a carbonaceous reducing agent and a binder, and after mixing evenly, obtain a base material; the reducing agent is anthracite, the carbon ratio is 2wt% of the weight of the germanium-containing material, and its particle size is less than 50 μm; the binder is bentonite, and its dosage is 1wt% of the weight of the germanium-containing material.

[0059] Pelletizing: Pelletize the base material to obtain a pelletized material with a certain strength and a certain particle size.

[0060] Drying: Dry the pelletized material (the drying temperature is 105°C and the time is 480 min), and the particle size of the dried pellet is 8 - 30 mm.

[0061] (2) Carbothermal reduction - sulfurization volatilization

[0062] Add the dried pelletized material obtained in step (1) to the reaction device, and carry out carbothermal reduction - sulfurization volatilization at a temperature of 900°C for 60 min. Obtain soot rich in valuable metals such as germanium and reduced slag.

[0063] After detection, the germanium volatilization rate is greater than 99%, the lead volatilization rate is less than 5%, and the zinc volatilization rate is less than 7%; the main chemical components of the soot are as follows: Pb 60.88wt%, Zn 8.33wt%, Ge 2.17wt%, S 9.71wt%, and other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3, etc., the content is less than 0.2%.

[0064] Example 2:

[0065] In this embodiment, the germanium-containing material contains 14.76 wt% Zn, 10.32 wt% Pb, 14.77 wt% S, and 1310.21 g / t Ge; the specific implementation steps are as follows:

[0066] (1)Material preparation

[0067] Batching: Mix the dried germanium-containing material with a carbonaceous reducing agent and a binder, and after mixing evenly, obtain a base material; the reducing agent is lignite, the carbon ratio is 5 wt% of the weight of the germanium-containing material, and its particle size is less than 50 μm; the binder is lime and bentonite, the dosage of lime is 2 wt% of the weight of the germanium-containing material, and the dosage of bentonite is 1 wt% of the weight of the germanium-containing material.

[0068] Pelletizing: Pelletize the base material to obtain pelletized materials with a certain strength and a certain particle size.

[0069] Drying: Dry the pelletized materials (the drying temperature is 250 °C and the time is 120 min), and the particle size of the pelletized materials obtained after drying is 8 - 30 mm.

[0070] (2)Carbothermal reduction - sulfide volatilization

[0071] Add the dried pelletized materials obtained in step (1) to the reaction device, and carry out carbothermal reduction - sulfide volatilization at a temperature of 950 °C for 30 min. Obtain fume rich in valuable metals such as germanium and reduced slag.

[0072] After detection, the germanium volatilization rate is greater than 99%, the lead volatilization rate is less than 9%, and the zinc volatilization rate is less than 7%; the main chemical components of the fume are as follows: Pb 41.2 wt%, Zn 29.32 wt%, Ge 2.33 wt%, S 7.82 wt%, and the contents of other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3 are less than 0.2%.

[0073] Example 3:

[0074] In this embodiment, the germanium-containing material contains 14.54 wt% Zn, 25.52 wt% Pb, 5.31 wt% S, and 783.47 g / t Ge;

[0075] The specific implementation steps are as follows:

[0076] (1)Material preparation

[0077] Ingredients: The dried germanium-containing material is mixed with a carbonaceous reducing agent and a binder. After being evenly mixed, a base material is obtained. The reducing agent is coke, and the carbon ratio is 3 wt% of the weight of the germanium-containing material, with a particle size less than 50 μm. The binder is an organic binder (the organic binder is composed of sodium carboxymethyl cellulose and synthetic resin, mainly composed of three elements C, H, and O, and the sum of the contents of these three elements is greater than 90 wt%), and its dosage is 2 wt% of the weight of the germanium-containing material.

[0078] Pelletizing: The base material is pelletized to obtain pelletized materials with a certain strength and a certain particle size.

[0079] Drying: The pelletized materials are dried (the drying temperature is 300 °C and the time is 60 min). The particle size of the pelletized materials obtained after drying is 8 - 30 mm.

[0080] (2) Carbothermal reduction - sulfurization volatilization

[0081] The dried pelletized materials obtained in step (1) are added to a reaction device, and carbothermal reduction - sulfurization volatilization is carried out at a temperature of 920 °C for 45 min. Smokes and dust rich in valuable metals such as germanium and reduced slag are obtained.

[0082] After detection, the germanium volatilization rate is greater than 99%, the lead volatilization rate is less than 8%, and the zinc volatilization rate is less than 7%; the main chemical components of the smokes and dust are as follows: Pb 53.33 wt%, Zn 20.12 wt%, Ge 2.43 wt%, S 4.73 wt%, and the contents of other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3 are less than 0.2%.

[0083] Example 4:

[0084] In this example, the germanium-containing material contains Zn 6.23 wt%, Pb 34.19 wt%, S 14.81 wt%, and Ge 4893.22 g / t;

[0085] The specific implementation steps are as follows:

[0086] (1) Material preparation

[0087] Ingredients: The dried germanium-containing material is mixed with a carbonaceous reducing agent and a binder. After being evenly mixed, a base material is obtained. The reducing agent is coke, and the carbon ratio is 3 wt% of the weight of the germanium-containing material, with a particle size less than 50 μm. The binder is an organic binder (the organic binder is composed of sodium carboxymethyl cellulose and synthetic resin, mainly composed of three elements C, H, and O, and the sum of the contents of these three elements is greater than 90 wt%), and its dosage is 2 wt% of the weight of the germanium-containing material.

[0088] Pelletizing: Pelletize the base material to obtain pelletized materials with a certain strength and a certain particle size.

[0089] Drying: Dry the pelletized materials (the drying temperature is 200 °C and the time is 180 min). The particle size of the pellets obtained after drying is 8 - 30 mm.

[0090] (2) Carbothermal reduction - sulfurization volatilization

[0091] Add the dried pelletized materials obtained in the above step (1) to the reaction device, and carry out carbothermal reduction - sulfurization volatilization at a temperature of 900 °C for 45 min. Soot rich in valuable metals such as germanium and reduced slag are obtained.

[0092] After detection, the germanium volatilization rate is greater than 99%, the lead volatilization rate is less than 4%, and the zinc volatilization rate is less than 6%; the main chemical components of the soot are as follows: Pb 51.21%, Zn 4.83%, Ge 5.61%, S 9.88%, and the contents of other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3 are less than 0.2%.

[0093] Example 5:

[0094] In this example, the germanium-containing material contains Zn 6.23 wt%, Pb 34.19 wt%, S 14.81 wt%, and Ge 4893.22 g / t;

[0095] The specific implementation steps are as follows:

[0096] (1) Material preparation

[0097] Batching: Mix and batch the dried germanium-containing material with a carbonaceous reducing agent and a binder. After mixing evenly, a base material is obtained; the reducing agent is anthracite, and the carbon ratio is 0 - 5 wt% of the weight of the germanium-containing material. The influence of the carbon ratio on the volatilization rates of lead, zinc, and germanium is shown in Table 1 below. The particle size of the anthracite is less than 50 μm; the binder is an organic binder (the organic binder is composed of sodium carboxymethyl cellulose and synthetic resin, mainly composed of three elements C, H, and O, and the sum of the contents of these three elements is greater than 90 wt%), and its dosage is 2 wt% of the weight of the germanium-containing material.

[0098] Pelletizing: Pelletize the base material to obtain pelletized materials with a certain strength and a certain particle size.

[0099] Drying: Dry the pelletized materials (the drying temperature is 150 °C and the time is 240 min). The particle size of the pellets obtained after drying is 8 - 30 mm.

[0100] (2) Carbothermal reduction - sulfurization volatilization

[0101] Add the dried agglomerated material obtained in the step (1) to a reaction device, and carry out carbothermal reduction-vaporization-sulfurization at a temperature of 900 °C for 45 min to obtain soot rich in valuable metals such as germanium and reduced slag.

[0102]

[0103] After testing, the carbon ratio has no obvious effect on the volatilization rates of Pb and Zn, and the volatilization rates of Pb and Zn are both less than 6%. The carbon ratio has a greater effect on the volatilization rate of Ge. When the carbon ratio reaches 3 wt%, Ge is basically completely volatilized.

[0104] The main chemical components of the soot obtained when the carbon ratio is 0-3 wt% are as follows: Pb 49-53 wt%, Zn 3-5 wt%, Ge 0.5-2.7 wt%, S 9-11 wt%, and other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3, etc., have a content of less than 0.2%. When the carbon ratio is 3-5 wt%, Pb 49-53 wt%, Zn 3-5 wt%, Ge 5-6 wt%, S 9-11 wt%, and other impurity components such as Fe, As, SiO2, CaO, MgO, and Al2O3, etc., have a content of less than 0.2%. When the carbon ratio exceeds 5 wt% (compared with 5 wt%), it has no effect on the germanium volatilization rate, but synchronously increases the lead-zinc volatilization rate, and the increased amplitude is relatively large, which is not conducive to the selective volatilization of Ge and Pb, Zn.

[0105] Comparative Example 2

[0106] In this example, the germanium-containing material contains Zn 12.23 wt%, Pb 31.19 wt%, S 7.21 wt%, Ge 2693.22 g / t;

[0107] The specific implementation steps are as follows:

[0108] (1) Material preparation

[0109] Batching: Mix the dried germanium-containing material with a carbonaceous reducing agent and a binder, and after mixing evenly, obtain a base material; the reducing agent is anthracite, the carbon ratio is 3% of the weight of the germanium-containing material, and its particle size is less than 50 μm; the binder is bentonite, and its dosage is 2% of the weight of the germanium-containing material.

[0110] Pelletizing: Pelletize the base material to obtain an agglomerated material with a certain strength and a certain particle size.

[0111] Drying: Dry the agglomerated material (the drying temperature is 120 °C and the time is 360 min), and the particle size of the agglomerated material obtained after drying is 8-30 mm.

[0112] (2)Carbothermal reduction - sulfurization volatilization

[0113] Add the dried agglomerates obtained in the step (1) into the reaction device, and carry out carbothermal reduction - sulfurization volatilization at a temperature of 850 °C for a reaction time of 60 min. Obtain dust rich in valuable metals such as germanium and reduced slag.

[0114] After detection, the germanium volatilization rate is less than 1.5%, the lead volatilization rate is less than 2%, and the zinc volatilization rate is less than 1%.

Claims

1. A method for selectively and efficiently recovering germanium from germanium-containing materials by volatilization, characterized in that, It includes the following steps: Step 1 Mix and proportion the dried germanium-containing material with a carbonaceous reducing agent and a binder. After mixing evenly, pelletize and dry to obtain a pelletized material with a sulfur content of 4.5 - 14 wt%. The dosage of the carbonaceous reducing agent is 2 - 5% of the weight of the germanium-containing material; the dosage of the binder is 1 - 3% of the weight of the germanium-containing material; Step 2 Add the dried pelletized material obtained in Step 1 to a reaction device and carry out carbothermal reduction-sulfurization volatilization at a temperature of 880 - 950 °C for at least 30 min to obtain a soot rich in valuable metals such as germanium and reduced slag.

2. The method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials according to claim 1, wherein: In Step 1, the germanium-containing material is germanium-containing slag produced in the process of zinc hydrometallurgy, and the germanium-containing slag contains 5 - 15 wt% of S.

3. A method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials according to claim 1, characterized in that: In Step 1, in the germanium-containing material, the content of Zn is 5 - 15 wt%, the content of Pb is 5 - 35 wt%, the content of S is 5 - 15 wt%, and the content of Ge is 200 - 5000 g / t.

4. A method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials according to claim 1, characterized in that: The carbonaceous reducing agent is one or a mixture of two of anthracite, lignite, and coke; the particle size of the reducing agent is less than 50 μm.

5. A method for selectively and efficiently volatilizing and recovering germanium from germanium-containing materials according to claim 1, characterized in that: The binder is one or a mixture of two of bentonite, lime, and organic binder.

6. The method for selectively and efficiently recovering germanium by volatilizing germanium-containing materials according to claim 1, characterized in that: In Step (2), the volatilization rates of zinc and lead are less than 10%, and the volatilization rate of germanium is greater than 99%; the content of Ge in the obtained soot is greater than 1.5 wt%.

7. A method for selectively and efficiently recovering germanium by volatilization from germanium-containing materials according to claim 6, characterized in that: The obtained soot includes, by mass percentage: Pb 30 - 60 wt%, Zn 10 - 40 wt%, Ge 1.5 - 5 wt%, S 5 - 10 wt%, and other impurity components are less than 0.2 wt%.

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