Chlorination distillation method with low hydrochloric acid concentration in germanium extraction process

Abstract

This invention relates to a low-hydrochloric acid concentration chlorination distillation method in the germanium extraction process, belonging to the field of germanium recovery and extraction technology. An HCl solution and a chloride salt are mixed as a leachate. The leachate is then mixed with a germanium-rich raw material and subjected to chlorination distillation. After cooling, the germanium-rich distillate, HCl absorbent, and distillation residue are collected. This invention employs a chloride salt-assisted dilute acid leaching method, significantly reducing the acid concentration and acid consumption in the chlorination distillation process. Simultaneously, the germanium leaching rate can reach over 97%, and the germanium recovery rate remains at a high level, exceeding 94%.

Description

Technical Field

[0001] This invention relates to the field of germanium recovery and extraction technology, specifically to a chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process, which can realize the recycling of materials in the process. Background Technology

[0002] Germanium, as a strategic rare metal, plays an irreplaceable role in high-tech industries such as national defense and aerospace due to its excellent optical properties and semiconductor characteristics. In the current production of high-purity germanium materials, chlorination distillation is still widely used as a key step in the extraction and preliminary purification of germanium from enriched materials or intermediate products. Chlorination distillation first converts germanium into volatile germanium tetrachloride (GeCl4), and then achieves efficient separation from other impurities through distillation, thereby significantly improving the efficiency and purity of subsequent purification. There are also many research reports on germanium extraction by chlorination distillation in the existing technology, such as the method for recovering germanium from lignite dust disclosed in CN104911363A, and the production method of high-purity germanium dioxide disclosed in CN115650282A. In addition, the article "Optimization of Chlorination Leaching of Germanium-Containing Lignite Dust and Kinetics of Arsenic Precipitation" conducted a detailed study on the leaching behavior of different germanium and arsenic in germanium-containing lignite dust in the HCl system based on the chemical phase selective dissolution method. See: Chinese Journal of Nonferrous Metals, 2025, 35(04), Li Shuai et al. The article “Research on Process for Improving the Recovery Rate of Germanium-Containing Coal Dust by Chlorination Distillation” studies a method for recovering germanium by distillation after alkali heating pretreatment. See: Rare Metals, 2012, 36(05), Pu Shikun et al.

[0003] However, germanium tetrachloride readily undergoes hydrolysis in a weakly acidic environment, thus reducing the germanium recovery rate. Current technologies often use a high concentration of hydrochloric acid (9 mol / L) for chlorination distillation to prevent this hydrolysis. This results in excessively high hydrochloric acid concentrations in the waste liquid, increasing the amount of alkali used in subsequent acid-base neutralization processes and the amount of waste residue, thereby raising the cost of germanium recovery. Therefore, how to reduce the hydrochloric acid concentration in the chlorination distillation process while maintaining a high germanium recovery rate has become an urgent problem to be solved. Summary of the Invention

[0004] In view of the aforementioned state of the prior art, this invention discovers that in the chlorination distillation process for germanium extraction, using a mixture of HCl solution and chloride salt as the leachate for chlorination distillation of germanium-rich raw materials can maintain a high germanium recovery rate while reducing the HCl concentration, thereby reducing the amount of alkali used and the amount of waste residue produced in subsequent acid-base neutralization processes, and thus reducing the cost of germanium extraction. This invention is based on the above discovery.

[0005] Therefore, the purpose of this invention is to provide a chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process. This solves the problems of limited germanium extraction efficiency, high acid concentration, and large waste residue production in existing chlorination distillation processes.

[0006] The technical solution for achieving the above-mentioned objectives can be summarized as follows:

[0007] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0008] An HCl solution and a chloride salt were mixed to form a leachate. The leachate was then mixed with a germanium-rich raw material and subjected to chlorination distillation. After cooling, the germanium-rich distillate, HCl absorbent, and distillation residue were collected.

[0009] According to the present invention, preferably, the chloride salt is at least one of AlCl3, FeCl3, CaCl2, and MgCl2.

[0010] According to the present invention, preferably, the mass content of germanium element in germanium-rich flue dust is not less than 0.2%.

[0011] According to the present invention, preferably, the concentration of HCl solution in the leachate is 1~5 mol / L, and the concentration of chloride salt is 1~8 mol / L.

[0012] According to the present invention, preferably, the liquid-solid ratio of the leachate to the germanium-rich raw material is 1:1 to 12:1 mL / g.

[0013] According to the present invention, preferably, the chlorination distillation temperature is 80~140°C.

[0014] According to the present invention, preferably, the chlorination distillation process is carried out under negative pressure conditions, and the pressure of the negative pressure is 0.01~0.04 MPa.

[0015] According to the present invention, preferably, it further includes a process for further processing of the distillation residue, comprising the following steps:

[0016] The distillation residue is subjected to a first solid-liquid separation to obtain filter residue and filtrate. Alkali metal oxides are added to the filtrate for acid-base neutralization to bring the pH of the filtrate to 7-8. The filtrate is then subjected to a second solid-liquid separation to obtain iron-aluminum rich slag and chloride salt solution. The HCl absorption solution and chloride salt solution are used to prepare leachate for recycling.

[0017] According to the present invention, preferably, the added alkali metal oxide is at least one selected from Al2O3, Fe2O3, CaO, and MgO.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. The present invention adopts a leaching method of chloride salt and dilute acid to greatly reduce the acid concentration and acid consumption of the chlorination distillation process. At the same time, the leaching rate of germanium can reach more than 97%, and the recovery rate of germanium remains at a high level, reaching more than 94%.

[0020] 2. This invention successfully separates germanium from arsenic and germanium from HCl using a negative pressure chlorination distillation method.

[0021] 3. This invention successfully recovers chloride salts through acid-base neutralization and evaporation crystallization, and the chloride salts can be returned to the leachate preparation process, realizing a closed-loop recycling of chloride salts and hydrochloric acid. Attached Figure Description

[0022] Figure 1 This is a process flow diagram of the low hydrochloric acid concentration chlorination distillation method in the germanium extraction process of this invention.

[0023] Figure 2 The X-ray diffraction analysis results are those of germanium-rich dust used in the embodiments of the present invention.

[0024] Figure 3 The X-ray diffraction analysis results are for germanium-rich flue dust distillation residue in Experiment Example 1 of this invention. Detailed Implementation

[0025] This invention uses a mixture of HCl solution and chloride salt as the leaching solution for chlorination distillation of germanium-rich raw materials, which can reduce the HCl concentration while maintaining a high germanium recovery rate. This reduces the amount of alkali used and the amount of waste residue produced in subsequent acid-base neutralization processes, thereby lowering the cost of germanium extraction.

[0026] The present invention provides a method for chlorination distillation with low hydrochloric acid concentration in the germanium extraction process, comprising the following steps:

[0027] An HCl solution and a chloride salt were mixed to form a leachate. The leachate was then mixed with a germanium-rich raw material and subjected to negative pressure chlorination distillation. After cooling, the germanium-rich distillate, HCl absorbent, and distillation residue were collected.

[0028] According to the present invention, the main non-oxygen elements in the germanium-rich raw material include Si, Fe, Al, Ca, Mg, As, Ge, etc.

[0029] In one or more preferred embodiments, the mass content of germanium in the germanium-rich flue dust is ≥0.2%.

[0030] According to the present invention, adding chloride salts to the hydrochloric acid leaching system significantly increases the effective concentration of chloride ions in the solution, thereby enhancing the activity of the leachate. The present invention can maintain a high germanium recovery rate while reducing the hydrochloric acid concentration, and simultaneously reduce the amount of waste acid generated, thus lowering subsequent treatment costs.

[0031] In one or more preferred embodiments, the chloride salt is at least one of AlCl3, FeCl3, CaCl2, and MgCl2.

[0032] According to the present invention, a high concentration of hydrochloric acid is not required after adding chloride salt to achieve a good chlorination distillation effect, thereby leaching and distilling out germanium to the maximum extent.

[0033] In one or more preferred embodiments, the concentration of the HCl solution in the leachate is 1 to 5 mol / L, for example: 2 mol / L, 3 mol / L, 4 mol / L; and the concentration of the chloride salt is 1 to 8 mol / L, for example: 2 mol / L, 3 mol / L, 4 mol / L, 6 mol / L.

[0034] According to the present invention, the liquid-solid ratio of the leachate to the germanium-rich raw material is controlled to maximize the leaching of germanium.

[0035] In one or more preferred embodiments, the liquid-solid ratio of the leachate to the germanium-rich raw material is 1:1 to 12:1 mL / g.

[0036] The chemical reactions that occur after the leachate is mixed with the germanium-rich raw material are shown in Table 1:

[0037] Table 1. Major chemical reactions occurring during leaching.

[0038]

[0039] According to the present invention, germanium is converted into volatile germanium tetrachloride (GeCl4) during the leaching process, and efficient separation from other impurities is achieved by distillation. GeCl4 is a colorless liquid, soluble in concentrated hydrochloric acid and dilute hydrochloric acid, with a saturated vapor pressure of 10.13 kPa (20°C) and a boiling point of 84°C. The temperature of the chlorination distillation is selected to ensure that GeCl4 evaporates completely while minimizing the volatilization of impurities and HCl.

[0040] In one or more preferred embodiments, the chlorination distillation temperature is 80~140°C.

[0041] According to the present invention, negative pressure chlorination distillation is used in the chlorination distillation process, which can successfully separate germanium from arsenic and germanium from HCl.

[0042] In one or more preferred embodiments, the chlorination distillation process is carried out under negative pressure conditions, with the negative pressure being 0.01~0.04 MPa, for example: 0.01 MPa, 0.02 MPa, 0.03 MPa.

[0043] According to the present invention, a further treatment process for the distillation residue is also included, comprising the following steps:

[0044] The distillation residue is subjected to a first solid-liquid separation to obtain filter residue and filtrate. Alkali metal oxides are added to the filtrate for acid-base neutralization to bring the pH of the filtrate to 7-8. The filtrate is then subjected to a second solid-liquid separation to obtain iron-aluminum rich slag and chloride salt solution. The HCl absorption solution and chloride salt solution are used to prepare leachate for recycling.

[0045] According to the present invention, the distillation residue mainly contains FeCl3, AlCl3, CaCl2, and MgCl2. Adding alkali metal oxides can neutralize hydrochloric acid and react to generate chloride salts, which can be returned to prepare leachate, thus realizing the recycling of materials.

[0046] In one or more preferred embodiments, the added alkali metal oxide is at least one selected from Al2O3, Fe2O3, CaO, and MgO.

[0047] According to the present invention, a preferred embodiment of the chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0048] (1) Material preparation: Prepare a certain concentration of HCl solution and mix it with chloride salt to obtain leachate. Mix the leachate with germanium-rich flue dust in a certain liquid-solid ratio.

[0049] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation under certain distillation temperature and certain negative pressure conditions. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0050] (3) Solid-liquid separation: The distillation residue from step (2) is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0051] (4) Acid-base neutralization: Add alkali metal oxide to the filtrate in step (3) to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7~8;

[0052] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0053] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0054] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments and implementation schemes of the present invention will be further described in detail below with reference to the accompanying drawings. It is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of them. The following description of at least one embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0055] The X-ray diffraction analysis results of the germanium-rich raw materials used in the following examples are as follows: Figure 2 As shown. By Figure 2 It can be seen that the main elements in germanium-rich flue dust include Si, Fe, Ca, Mg, and Ge, and the contents of the main elements are shown in Table 2:

[0056] Table 2. Main element content of germanium-rich dust

[0057]

[0058] Example 1:

[0059] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0060] (1) Material preparation: Prepare a leachate solution containing 5 mol / L HCl and 4 mol / L CaCl2, and mix the leachate solution with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0061] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 140℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0062] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0063] (4) Acid-base neutralization: Add CaO to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0064] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0065] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0066] Example 2:

[0067] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0068] (1) Material preparation: Prepare a leachate solution containing 5 mol / L HCl and 3 mol / L CaCl2, and mix the leachate solution with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0069] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 140℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0070] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0071] (4) Acid-base neutralization: Add CaO to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0072] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0073] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0074] Example 3:

[0075] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0076] (1) Material preparation: Prepare a leachate solution containing 4 mol / L HCl and 3 mol / L CaCl2, and mix the leachate solution with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0077] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 140℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0078] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0079] (4) Acid-base neutralization: Add CaO to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0080] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0081] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0082] Example 4:

[0083] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0084] (1) Material preparation: Prepare a leachate containing 5 mol / L HCl and 2.5 mol / L AlCl3, and mix the leachate with germanium-rich flue dust at a liquid-solid ratio of 12:1 mL / g.

[0085] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 140℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0086] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0087] (4) Acid-base neutralization: Add Al2O3 to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0088] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0089] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0090] Example 5:

[0091] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0092] (1) Material preparation: Prepare a leachate solution containing 5 mol / L HCl and 4 mol / L MgCl2, and mix the leachate solution with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0093] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 130℃, a negative pressure of 0.02 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0094] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0095] (4) Acid-base neutralization: Add MgOH to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0096] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0097] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0098] Example 6:

[0099] The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process includes the following steps:

[0100] (1) Material preparation: The 5mol / L HCl and 4mol / L CaCl2 synergistic leachate was prepared using the recovered HCl absorbent and chloride salt solution. The leachate was mixed with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0101] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 130℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0102] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0103] (4) Acid-base neutralization: Add CaO to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0104] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution;

[0105] (6) Recycling: Use the HCl absorption liquid and chloride salt solution obtained in steps (2) and (5) for the leachate in step (1) and repeat the above leaching process.

[0106] Comparative Example 1:

[0107] (1) Material preparation: Prepare a 5mol / L HCl leachate and mix the leachate with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0108] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 140℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0109] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0110] (4) Acid-base neutralization: Add CaO to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0111] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution (waste salt).

[0112] Comparative Example 2:

[0113] (1) Material preparation: Prepare 9mol / L HCl leachate, and mix the leachate with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0114] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 130℃, a negative pressure of 0.02 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0115] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0116] (4) Acid-base neutralization: Add CaO to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0117] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and chloride salt solution (waste salt).

[0118] Comparative Example 3:

[0119] (1) Material preparation: A 5 mol / L HCl and 4 mol / L Al2(SO4)3 synergistic leachate was prepared using the recovered HCl absorbent and chloride salt solution. The leachate was mixed with germanium-rich flue dust at a liquid-solid ratio of 10:1 mL / g.

[0120] (2) Negative pressure chlorination distillation: The material obtained in step (1) is subjected to negative pressure chlorination distillation at a distillation temperature of 140℃, a negative pressure of 0.01 MPa, and a distillation time of 2h. After cooling, germanium-rich distillate, HCl absorption liquid and distillation residue are collected.

[0121] (3) Solid-liquid separation: The distillation residue is subjected to solid-liquid separation to obtain filter residue and filtrate;

[0122] (4) Acid-base neutralization: Add Al2O3 to neutralize the acid and base of the filtrate, so that the pH of the filtrate is 7;

[0123] (5) Solid-liquid separation: The filtrate is subjected to solid-liquid separation to obtain iron-aluminum slag and salt solution (waste salt).

[0124] Experimental Example 1:

[0125] The X-ray fluorescence spectrum of the distillation residue obtained in step (3) of Example 1 was tested, as shown in the figure. Figure 3 As shown.

[0126] The content of major elements in the iron-aluminum slag obtained in step (5) of test example 1 is shown in Table 3.

[0127] Table 3. Main element content of neutralization residue.

[0128]

[0129] Experimental Example 2

[0130] The germanium extraction performance of Test Examples 1-6 and Comparative Examples 1-3 is shown in Table 4.

[0131] Table 4

[0132]

[0133] Analysis of Example 1 and Comparative Example 1 shows that the introduction of calcium chloride can significantly improve the leaching rate and recovery rate of germanium. Analysis of Example 1 and Comparative Example 2 shows that, while maintaining a similar germanium leaching rate and recovery rate, the introduction of calcium chloride can significantly reduce the concentration of hydrochloric acid and significantly improve the recovery rate of hydrochloric acid.

[0134] Comparative Example 3 shows that non-chloride salts, due to their inability to provide chloride ions, have no promoting effect on the chlorination distillation process of germanium, verifying the irreplaceable nature of chloride salts in this technical solution.

[0135] In this experimental example, each indicator was calculated using the following formula:

[0136] M1 and M2 represent the mass (g) of the raw material and the leaching residue, respectively; C1, C2, C3 and C4 represent the germanium content (%) in the raw material, distillation residue, germanium-rich distillate and HCl absorption liquid, respectively; H1, H2, H3 and H4 represent the acid concentration (mol / L) of the leaching liquid, germanium-rich distillate, HCl absorption liquid and distillation residue, respectively; and V1, V2, V3 and V4 represent the volume (L) of the leaching liquid, germanium-rich distillate, HCl absorption liquid and distillation residue, respectively.

[0137] ;

[0138] ;

[0139] ;

[0140] ;

[0141] The method for calculating the arsenic evaporation rate is the same as that for germanium.

[0142] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of ​​the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A chlorination distillation method with low concentration of hydrochloric acid in a germanium extraction process, comprising the following steps: mixing HCl solution and chloride salt as leaching solution, mixing the leaching solution with germanium-rich raw material, and then performing chlorination distillation, and cooling and collecting to obtain germanium-rich distillate, HCl absorption solution, and distillation residue.

2. The germanium extraction process low hydrochloric acid concentration distillation method according to claim 1, characterized by, The chloride salt is at least one of AlCl3, FeCl3, CaCl2, and MgCl2.

3. The distillation method of claim 1, wherein the distillation method is a chlorination distillation method of a low concentration of hydrochloric acid in a germanium extraction process. The mass content of germanium in the germanium fume is greater than or equal to 0.2%.

4. The chlorination distillation method with low hydrochloric acid concentration in the germanium extraction process according to claim 1, characterized in that, The concentration of HCl solution in the leaching solution is 1-5 mol / L, and the concentration of chloride salt is 1-8 mol / L.

5. The distillation method of claim 1, wherein the concentration of the hydrochloric acid is 0.1 to 0.5 mol / L. The liquid-solid ratio of the leaching solution to the germanium-rich raw material is 1:1-12:1 mL / g.

6. The distillation method of claim 1, wherein the concentration of the hydrochloric acid is 0.1 to 0.5 mol / L. The chlorination distillation temperature is 80-140°C.

7. The distillation method of claim 1, wherein the distillation method is a chlorination distillation method of a low concentration of hydrochloric acid in a germanium extraction process. The chlorination distillation process is performed under negative pressure.

8. The distillation method of claim 7, wherein the distillation method is a chlorination distillation method for producing germanium in a low concentration of hydrochloric acid. The negative pressure is 0.01-0.04 MPa.

9. The method for chlorination distillation with low hydrochloric acid concentration in the germanium extraction process according to any one of claims 1-8, characterized in that, Further treatment of the distillation residue is also included, comprising the following steps: performing primary solid-liquid separation on the distillation residue to obtain residue and filtrate, adding alkali metal oxide to the filtrate to perform acid-base neutralization to make the pH of the filtrate 7-8, performing secondary solid-liquid separation on the filtrate to obtain iron and aluminum-rich residue and chloride salt solution; the HCl absorption solution and the chloride salt solution are used to prepare the leaching solution for recycling.

10. The distillation method of claim 9, wherein the distillation method is a chlorination distillation method for a germanium extraction process with a low concentration of hydrochloric acid, characterized by, The added alkali metal oxide is at least one of Al2O3, Fe2O3, CaO, and MgO.

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