A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution

Abstract

The present invention relates to a method for extracting germanium from a germanium-containing zinc oxide smoke leachate, and belongs to the technical field of germanium extraction. The present invention mainly includes four steps of iron coordination, germanium reduction, neutralization and iron removal, and deboronization. In the iron coordination step, a small molecule organic acid is added to coordinate with divalent iron and trivalent iron to prevent the consumption of a reducing agent; in the step of reducing germanium, the addition of borohydride can directly reduce the germanium in the acid leaching solution to germane gas; in the step of neutralization and iron removal, roasted sand is sprayed into the acid leaching solution to neutralize the pH to 5-5.2, and pyrolusite is added to remove iron and arsenic; in the deboronization step, a boron removal resin is added to the acid leaching solution, and purification electrolysis is performed after boron adsorption. The present invention can directly extract germanium from a germanium-containing zinc oxide smoke leachate, and the loss of germanium and valuable metals in the process is low, the direct yield is high, the production process is simple, the germanium production cycle is greatly shortened, and it is provided for the production of scattered metals.

Description

Technical Field

[0001] The invention belongs to the technical field of germanium extraction, and in particular relates to a method for extracting germanium from germanium-containing zinc oxide smoke leaching solution. Background Art

[0002] Germanium is a non-renewable, scarce and dispersed element. Germanium has optical properties such as high infrared refractive index and low dispersion rate and excellent mechanical properties. It is often used in high-tech fields such as infrared optics, fiber optics, solar cells, polymerization catalysts and medicine. It is also widely used in information communication, biological sciences, modern aviation, modern military and high-energy fields. With the continuous development and improvement of these fields, the demand for germanium materials is growing.

[0003] The tannin germanium precipitation process is currently the most traditional and mature process for extracting germanium from germanium-containing zinc oxide smoke leaching solution. It requires multiple steps such as coordination germanium precipitation-roasting-distillation-hydrolysis, etc. The process is long, the organic matter consumption is high, the impact on electrolysis is great, and the loss rate of germanium and valuable metals is high. Summary of the invention

[0004] In order to overcome the problems existing in the background technology, the present invention provides a method for extracting germanium from germanium-containing zinc oxide smoke leaching solution. The present invention aims to solve the problems of high organic matter consumption, long process flow and high germanium loss rate in the existing tannin germanium precipitation, and provides a new method for extracting germanium from germanium-containing zinc oxide smoke leaching solution in one step. Based on the reduction potential of germanium (Ge 4+ |Ge, -0.12V) is much smaller than the reduction potential of zinc (Zn 2+ | Zn, -0.7618 V), adding borohydride can directly reduce germanium. At the same time, due to the reduction potential of iron (Fe 3+ |Fe, -0.04V) is smaller than germanium and is masked by coordination with small molecule acids.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution comprises the following steps:

[0007] S1, iron coordination: adding small molecule organic acid to the leaching solution to coordinate with divalent iron and trivalent iron to prevent consumption of reducing agent;

[0008] S2, reduction of germanium: adding borohydride to the solution after iron coordination can directly reduce the germanium in the acid leaching solution to GeH4, and then absorbing and hydrolyzing GeH4 to generate germanium dioxide;

[0009] S3, neutralization and iron removal: spray the solution after germanium separation into roasted sand, neutralize the pH to 5-5.2, then add pyrolusite to oxidize and remove arsenic and iron, and separate the iron-arsenic slag from the liquid and solid;

[0010] S4, deboronization: Adding boron removal resin to the zinc-containing liquid after neutralization and iron removal, purifying and electrolyzing to obtain zinc after adsorbing boron.

[0011] Furthermore, in the step S1, the germanium content in the leaching solution is 30 mg / L-300 mg / L, the zinc content is 40-200 g / L, and the Fe content is 3+ The content is 5-20mg / L, Fe 2+ The content is 1-5g / L, the acidity is 10-20g / L, and the leaching solution temperature is 60~65℃.

[0012] Furthermore, in the step S1, the small molecule organic acid is one or more of gallic acid, oxalic acid, lactic acid, and salicylic acid, the added amount is 1 to 2 times the theoretical value of the total iron amount, and the coordination time is 20 to 40 minutes.

[0013] Furthermore, in the S2 step, the reducing agent is potassium borohydride or sodium borohydride, and the added amount is 52% to 100% of the mass of germanium; the absorption hydrolysis method of GeH4 is: using a vacuum device to introduce germane into a hydrolysis device for hydrolysis, controlling the water temperature to 17°C, the hydrolysis time to 1 to 2 hours, and then centrifuging to separate germanium dioxide.

[0014] Furthermore, in the step S3, pyrolusite is added until the solution turns yellow and then solid-liquid separation is performed to remove iron and arsenic slag; and the roasted sand is zinc sulfide roasted sand.

[0015] Furthermore, in the step S4, the boron removal resin is subjected to regeneration treatment by elution with sulfuric acid after adsorbing and removing boron.

[0016] Beneficial effects of the present invention:

[0017] (1) The present invention directly utilizes borohydride reduction to extract germanium, resulting in less loss of valuable metals and less loss of germanium;

[0018] (2) The present invention only requires the addition of a small amount of small molecule organic matter to extract germanium, and can subsequently be removed using a deboronized resin, which is friendly to electrolysis. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer, the preferred embodiments of the present invention will be described in detail below to facilitate understanding by technicians.

[0020] Example 1: The main chemical components of the germanium-containing zinc oxide smoke leaching solution in this example are shown in Table 1.

[0021] Table 1 Main chemical components of germanium-containing zinc oxide dust leaching solution

[0022]

[0023] It can be seen from the table that the germanium content of the germanium-containing zinc oxide smoke leaching solution is 35 mg / L, the zinc content is 45 g / L, and the Fe 2+ The content is 1g / L, Fe 3+ The content is 5mg / L;

[0024] A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution, the specific steps are as follows:

[0025] (1) Iron coordination: Add 3.34 g / L (1.1 times the iron coordination amount) of gallic acid to the acid leaching solution for coordination with divalent iron and trivalent iron. The coordination reaction time is 20 min to prevent consumption of the reducing agent.

[0026] (2) Reduction of germanium: After iron coordination, 18.22 mg / L sodium borohydride is added to the solution to directly reduce the germanium in the acid leaching solution to GeH4. The germane is introduced into the hydrolysis device by using a vacuum device for hydrolysis. The water temperature is controlled at 17°C and the hydrolysis time is 1 hour. Germanium dioxide is then separated by centrifugation.

[0027] (3) Neutralization and iron removal: After separating the germanium, add pyrolusite to the solution until the oxidation solution turns yellow, that is, all the ferrous iron is oxidized to trivalent iron. Spray zinc sulfide roasted sand to neutralize the acid leaching solution to pH 5, and separate the iron-arsenic slag from the liquid and solid.

[0028] (4) Deboronization: After neutralization and iron removal, the zinc-containing liquid passes through a boron removal resin and then undergoes purification electrolysis to obtain zinc flakes. After the resin is adsorbed to a certain degree, it is regenerated by elution with sulfuric acid.

[0029] The germanium recovery rate in this implementation is 99.1%, there is no zinc loss, and the germanium extraction time is within 2 hours.

[0030] Example 2: The main chemical components of the germanium-containing zinc oxide smoke leaching solution in this example are shown in Table 2.

[0031] Table 2 Main chemical components of germanium-containing zinc oxide smoke leaching solution

[0032]

[0033] It can be seen from the table that the germanium content of the germanium-containing zinc oxide smoke leaching solution is 90 mg / L, the zinc content is 135 g / L, and the Fe 2+ The content is 4g / L, Fe 3+ The content is 10mg / L;

[0034] A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution, the specific steps are as follows:

[0035] (1) Iron coordination: Add 14.78 g / L (1.5 times the iron coordination amount) of salicylic acid to the acid leaching solution for coordination with divalent iron and trivalent iron. The coordination reaction time is 30 min to prevent consumption of the reducing agent.

[0036] (2) Reduction of germanium: Adding 99.75 mg / L potassium borohydride to the solution after iron coordination can directly reduce the germanium in the acid leaching solution to GeH4. Use a vacuum device to introduce germane into the hydrolysis device for hydrolysis. Control the water temperature at 17°C and the hydrolysis time for 1.5 hours. Then centrifuge to separate germanium dioxide.

[0037] (3) Neutralization and iron removal: After separating the germanium, add pyrolusite to the solution until the oxidation solution turns yellow, that is, all the ferrous iron is oxidized to trivalent iron. Spray zinc sulfide roasted sand to neutralize the acid leaching solution to pH 5.1, and separate the iron-arsenic slag from the liquid and solid.

[0038] (4) Deboronization: After neutralization and iron removal, the zinc-containing liquid passes through a boron removal resin and then undergoes purification electrolysis to obtain zinc flakes. After the resin is adsorbed to a certain degree, it is regenerated by elution with sulfuric acid.

[0039] The germanium recovery rate in this implementation is 99.5%, there is no zinc loss, and the germanium extraction time is within 3 hours.

[0040] Example 3: The main chemical components of the germanium-containing zinc oxide smoke leaching solution in this example are shown in Table 3.

[0041] Table 3 Main chemical components of germanium-containing zinc oxide smoke leaching solution

[0042] Ge / (mg / L) <![CDATA[H + / (g / L)]]> <![CDATA[Fe 2+ / (g / L)]]> <![CDATA[Fe 3+ / (mg / L)]]> Zn / (g / L) 200 200 5 20 200

[0043] It can be seen from the table that the germanium content of the germanium-containing zinc oxide smoke leaching solution is 200 mg / L, the zinc content is 200 g / L, and the Fe 2+ The content is 5g / L, Fe 3+ The content is 20mg / L;

[0044] A new method for extracting germanium from germanium-containing zinc oxide smoke leaching solution in one step, the specific steps are as follows:

[0045] (1) Iron coordination: Add 16.08 g / L (twice the amount of iron coordination) of oxalic acid to the acid leaching solution to coordinate with divalent iron and trivalent iron. The coordination reaction time is 40 min to prevent the consumption of the reducing agent.

[0046] (2) Reduction of germanium: Adding 295.56 mg / L potassium borohydride to the solution after iron coordination can directly reduce the germanium in the acid leaching solution to GeH4. Use a vacuum device to introduce germane into the hydrolysis device for hydrolysis. Control the water temperature at 17°C and the hydrolysis time for 1 hour. Then centrifuge to separate germanium dioxide.

[0047] (3) Neutralization and iron removal: After separating the germanium, add pyrolusite to the solution until the oxidation solution turns yellow, that is, all the ferrous iron is oxidized to trivalent iron. Spray zinc sulfide roasted sand to neutralize the acid leaching solution to pH 5.2, and separate the iron-arsenic slag from the liquid and solid.

[0048] (4) Deboronization: After neutralization and iron removal, the zinc-containing liquid passes through a boron removal resin and then undergoes purification electrolysis to obtain zinc flakes. After the resin is adsorbed to a certain degree, it is regenerated by elution with sulfuric acid.

[0049] The germanium recovery rate in this implementation is 99.8%, there is no zinc loss, and the germanium extraction time is within 4 hours.

[0050] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution, characterized in that: The following steps are involved: S1, iron coordination: adding small molecule organic acid to the leaching solution to coordinate with divalent iron and trivalent iron to prevent consumption of reducing agent; S2, reduction of germanium: adding borohydride to the solution after iron coordination can directly reduce the germanium in the acid leaching solution to GeH4, and then absorbing and hydrolyzing GeH4 to generate germanium dioxide; S3, neutralization and iron removal: spray the solution after germanium separation into roasted sand, neutralize the pH to 5-5.2, then add pyrolusite to oxidize and remove arsenic and iron, and separate the iron-arsenic slag from the liquid and solid; S4, deboronization: Adding a boron removal resin to the zinc-containing liquid after neutralization and iron removal, purifying it after adsorbing boron, and electrolyzing it to obtain zinc.

2. A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: In the step S1, the germanium content in the leaching solution is 30 mg / L-300 mg / L, the zinc content is 40-200 g / L, and the Fe content is 3+ The content is 5-20mg / L, Fe 2+ The content is 1-5g / L, the acidity is 10-20g / L, and the leaching solution temperature is 60~65℃.

3. A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution according to any one of claims 1 or 2, characterized in that: In the step S1, the small molecule organic acid is one or more of gallic acid, oxalic acid, lactic acid, and salicylic acid, the added amount is 1 to 2 times the theoretical value of the total iron amount, and the coordination time is 20 to 40 minutes.

4. A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: In the step S2, the reducing agent is potassium borohydride or sodium borohydride, and the added amount is 52% to 100% of the mass of germanium; the absorption and hydrolysis method of GeH4 is: using a vacuum device to introduce germane into a hydrolysis device for hydrolysis, controlling the water temperature to 17°C, the hydrolysis time to 1 to 2 hours, and then centrifuging to separate germanium dioxide.

5. A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: In the step S3, pyrolusite is added until the solution turns yellow and then solid-liquid separation is performed to remove iron and arsenic slag; the roasted sand is zinc sulfide roasted sand.

6. A method for extracting germanium from germanium-containing zinc oxide smoke leaching solution according to claim 1, characterized in that: In the step S4, the boron removal resin is subjected to regeneration treatment by eluting with sulfuric acid after adsorbing and removing boron.