阅读说明：本技术 一种含砷锗铁的酸性溶液中砷锗的分离方法 (Method for separating arsenic and germanium from acidic solution containing arsenic, germanium and iron ) 是由 邓维 郑泽翰 洪涛 符致远 袁正兴 蒋炎顺 于 2021-09-06 设计创作，主要内容包括：本发明涉及湿法冶金技术领域,尤其是一种含砷锗铁的酸性溶液中砷锗的分离方法,包括以下步骤：1)将酸性溶液升温、氧化；2)所述氧化后溶液调节pH值,过滤,得到砷酸铁沉淀和除砷后液；3)将所述除砷后液还原至一定氧化还原电位值；4)将还原后溶液的pH值并向调pH后液按一定铁量缓慢氧化1-3h,氧化同时继续缓慢通碱至终点pH值为4.7-5.5,得到含铁锗共沉物的溶液；5)将含铁锗共沉物的溶液过滤、脱水,得到锗精矿。本发明将酸性溶液中锗砷沉淀深度优异,除砷后能有效保障锗金属回收过程沉淀结构控制,产出锗精矿品位可控且二次溶解性能优异。(The invention relates to the technical field of hydrometallurgy, in particular to a method for separating arsenic and germanium from an acid solution containing arsenic, germanium and iron, which comprises the following steps: 1) heating and oxidizing the acid solution; 2) adjusting the pH value of the oxidized solution, and filtering to obtain ferric arsenate precipitate and arsenic-removed solution; 3) reducing the arsenic-removed liquid to a certain oxidation-reduction potential value; 4) slowly oxidizing the pH value of the reduced solution and the pH-adjusted solution for 1-3h according to a certain iron amount, and continuously and slowly introducing alkali while oxidizing until the final pH value is 4.7-5.5 to obtain a solution containing the iron and germanium co-precipitates; 5) and filtering and dehydrating the solution containing the iron and germanium coprecipitation to obtain germanium concentrate. According to the invention, the germanium and arsenic precipitation depth in the acid solution is excellent, the precipitation structure control in the germanium metal recovery process can be effectively guaranteed after arsenic removal, the grade of the produced germanium concentrate is controllable, and the secondary dissolution performance is excellent.)

1. A method for separating arsenic and germanium from an acid solution containing arsenic, germanium and iron is characterized by comprising the following steps: the method comprises the following steps:

(1) heating the acid solution to 60-80 ℃, and adding an oxidant into the acid solution for oxidation, wherein the addition amount of the oxidant is 140-200% of a theoretical value required by the arsenic content in the oxidized acid solution;

(2) adding alkali liquor into the oxidized acidic solution to adjust the pH value to 2.0-2.4, and then filtering to obtain ferric arsenate precipitate and arsenic-removed solution;

(3) heating the arsenic-removed solution to 70-90 ℃, and then adding a reducing agent to reduce the arsenic-removed solution to a certain oxidation-reduction potential value;

(4) adding alkali liquor into the reduced solution to adjust the pH value to 2.4-3.8, adding an oxidant into the solution after the pH value is adjusted to perform oxidation for 1-3h, and continuously introducing the alkali liquor during and/or after the oxidation is finished until the pH value reaches 4.7-5.5 to obtain a solution containing the iron and germanium co-precipitates;

(5) and filtering and dehydrating the solution containing the iron and germanium coprecipitation to obtain germanium concentrate.

2. The method for separating arsenic and germanium from an acidic solution containing arsenic, germanium and iron as claimed in claim 1, wherein: in the step (1), the arsenic content in the initial acid solution is 0.45-0.75g/L, and the germanium content is 0.5-1.0 g/L; wherein the oxidant is hydrogen peroxide.

3. The method for separating arsenic and germanium from an acidic solution containing arsenic, germanium and iron as claimed in claim 1, wherein: and (4) adjusting the pH value of the alkali liquor in the step (2) and the step (4) to obtain an alkali liquor, wherein the alkali liquor is an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide.

4. The method for separating arsenic and germanium from an acidic solution containing arsenic, germanium and iron as claimed in claim 1, wherein: the reducing agent used in the step (3) is sodium sulfate.

5. The method for separating arsenic and germanium from an acidic solution containing arsenic, germanium and iron as claimed in claim 1, wherein: the oxidation-reduction potential value reduced by the reducing agent in the step (3) is 260mV-340 mV.

6. The method for separating arsenic and germanium from an acidic solution containing arsenic, germanium and iron as claimed in claim 1, wherein: the amount of the oxidant used in step (4) is based on the theoretical amount required for oxidizing the ferrous amount in the acidic solution, wherein the ferrous amount in the solution after the pH value is adjusted is calculated as a fixed amount of 2-4 g/L.

Technical Field

The invention relates to the technical field of hydrometallurgy, in particular to a method for separating arsenic and germanium from an acid solution containing arsenic, germanium and iron.

Background

In hydrometallurgical processes, arsenic from minerals can be leached out with acids or bases, which are highly detrimental to metallurgy and the environment, and must be removed from solution. Germanium is a light grey metal, also second only to silicon, an important semiconductor material, which was discovered by the german chemist wenckel in 1885 by spectroscopic analysis. Germanium is widely applied to the fields of electronics, optics, chemical engineering, biomedicine, energy and other high and new technologies, but independent germanium ore deposits rarely exist in the nature, germanium is mainly associated with other non-ferrous metal ores, and is very dispersed, and almost no more concentrated germanium ore exists, so that the germanium is called as 'rare metal', and has higher economic value.

The germanium-containing liquid produced in the non-ferrous metal smelting industry generally has low germanium concentration, complex components and large treatment capacity, and particularly, the arsenic content in the solution has great influence on the quality of germanium concentrate. The current conventional method is to recover germanium by adjusting the pH of the solution and then using tannin precipitation. However, the method is easy to generate free tannin in the sedimentation process, not only reduces the utilization efficiency of the tannin, but also is easy to cause the coprecipitation of metallic arsenic as an impurity, and causes the secondary pollution of the sediment. For the solution containing germanium and arsenic, the production cost of the method is higher than the use value of germanium, and resource waste is easily caused, so that the method has significance for exploring other precipitation methods to recover germanium and separate germanium and arsenic.

Disclosure of Invention

The invention provides a method for separating arsenic and germanium from an acid solution containing arsenic, germanium and iron to solve the technical defects, and the method realizes the high-efficiency and deep separation of germanium and arsenic elements by a step-by-step precipitation method.

The invention discloses a method for separating arsenic and germanium from an acid solution containing arsenic, germanium and iron, which comprises the following steps:

(1) heating the acid solution to 60-80 ℃, and adding an oxidant into the acid solution for oxidation, wherein the addition amount of the oxidant is 140-200% of a theoretical value required by the arsenic content in the oxidized acid solution;

(2) adding alkali liquor into the oxidized acidic solution to adjust the pH value to 2.0-2.4, and then filtering to obtain ferric arsenate precipitate and arsenic-removed solution;

(3) heating the arsenic-removed solution to 70-90 ℃, and then adding a reducing agent to reduce the arsenic-removed solution to a certain oxidation-reduction potential value;

(4) adding alkali liquor into the reduced solution to adjust the pH value to 2.4-3.8, adding an oxidant into the solution after the pH value is adjusted to perform oxidation for 1-3h, and continuously introducing the alkali liquor during and/or after the oxidation is finished until the pH value reaches 4.7-5.5 to obtain a solution containing the iron and germanium co-precipitates;

(5) and filtering and dehydrating the solution containing the iron and germanium coprecipitation to obtain germanium concentrate.

In the step (1), the arsenic content in the initial acid solution is 0.45-0.75g/L, and the germanium content is 0.5-1.0 g/L; wherein the oxidant is hydrogen peroxide.

And (4) adjusting the pH value of the alkali liquor in the step (2) and the step (4) to obtain an alkali liquor, wherein the alkali liquor is an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide.

The reducing agent used in step (3) is sodium sulfate, but is not limited to this reducing agent.

In the step (3), in order to control the structure transformation of the iron slag to the goethite during the iron-germanium coprecipitation, the Fe in the solution needs to be controlled³⁺And (4) concentration. To ensure Fe in the solution³⁺The concentration is lower than a certain value, and a potential control mode is adopted, so that the oxidation-reduction potential value reduced by the reducing agent is 260mV-340 mV.

In the step (4), in order to control the iron slag in the solution to form nuclei and grow in a goethite structure, Fe in the solution is oxidized and precipitated²⁺Oxidation to Fe³⁺Hydrolyzing the precipitate, wherein the amount of the oxidant is calculated according to the theoretical amount required for oxidizing the ferrous amount in the acidic solution, and the ferrous amount in the solution after the pH value is adjusted is calculated according to the fixed amount of 2-4 g/L.

In the step 2), in order to not influence the subsequent germanium precipitation effect, the arsenic concentration in the arsenic-removed liquid needs to be lower than 0.09 g/L. The concentration of arsenic in the arsenic-removed liquid is ensured to be lower than 0.09g/L by controlling the reaction temperature and the oxidation amount and controlling the pH value of the final arsenic removal.

Compared with the precipitation method in the prior art, the method for separating arsenic and germanium from the acidic solution containing arsenic, germanium and iron has the following advantages:

1) the invention realizes the high-efficiency and deep separation of germanium and arsenic elements by a step-by-step precipitation method, does not add any external precipitating agent, does not introduce impurities, and reduces the secondary pollution of impurity metal precipitates such as arsenic and the like to germanium precipitates.

2) The invention realizes the removal of arsenic in the form of ferric arsenate and the recovery and reclamation of germanium in the low-concentration germanium arsenic solution.

3) The germanium precipitation depth in the solution is excellent, the germanium precipitation rate can reach more than 85%, the grade of the produced germanium concentrate is controllable, and the secondary dissolution performance is excellent.

4) The process has simple operation condition and easily controlled reaction condition.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, features and effects according to the present invention will be made with reference to the accompanying drawings and preferred embodiments.

Example 1:

the invention discloses a method for separating germanium and arsenic in an acid solution, which has a process flow as shown in figure 1 and comprises the following steps:

(1) in the acid solution, the content of germanium is 0.658g/L, and the content of arsenic is 0.489 g/L;

(2) heating the acid solution to 70 ℃, and adding hydrogen peroxide into the acid solution to oxidize the acid solution according to 1.6 times of the theoretical oxidation amount of arsenic content in the acid solution to obtain oxidized solution;

(3) adjusting the pH value of the oxidized solution to 2.2 by using an aqueous solution (with the mass concentration of 32%) of sodium hydroxide, and enabling the solution to generate white precipitates;

(4) and (4) filtering and dehydrating the solution obtained in the step (3) to obtain precipitated slag ferric arsenate and arsenic-removed solution. Detection shows that the arsenic content in the arsenic-removed liquid is 0.066g/L, and the precipitation rate of arsenic calculated by the liquid is 86.5%; the content of germanium in the arsenic acid iron slag is 0.07 percent, and the loss rate of germanium in terms of slag is 0.77 percent.

(5) Continuously heating the arsenic-removed solution to 80 ℃ by using Na₂SO₃Reducing the potential of the solution to 300 mV; adjusting the pH of the reduced solution to 3.0 by using an aqueous sodium hydroxide solution, continuously introducing alkali, and simultaneously adding H with the mass concentration of 30% by using a peristaltic pump₂O₂Is subjected to oxidation of H₂O₂The amount of Fe in the oxidizing solution is 3g/L²⁺Calculating theoretical amount, and controlling the oxidation time for 1.5 h;

(6) and continuously introducing alkali liquor to the end point pH4.7 after the oxidation is finished, and filtering and separating to obtain a germanium-containing precipitate and a germanium-precipitated liquid. Through detection, the content of germanium in the germanium-containing precipitate is 6.738%, and the germanium precipitation rate of the slag is 92.24%.

Example 2:

the invention discloses a method for separating germanium and arsenic in an acid solution, which has a process flow as shown in figure 1 and comprises the following steps:

(1) in the acid solution, the content of germanium is 0.723g/L, and the content of arsenic is 0.491 g/L;

(2) heating the acid solution to 70 ℃, and adding hydrogen peroxide into the acid solution to oxidize the acid solution according to 1.8 times of the theoretical oxidation amount of arsenic content in the acid solution to obtain oxidized solution;

(3) adjusting the pH value of the oxidized solution to 2.2 by using an aqueous solution (with the mass concentration of 32%) of sodium hydroxide, and enabling the solution to generate white precipitates;

(4) and (4) filtering and dehydrating the solution obtained in the step (3) to obtain precipitated slag ferric arsenate and arsenic-removed solution. Detection shows that the arsenic content in the arsenic-removed liquid is 0.065g/L, and the precipitation rate of the arsenic calculated by the liquid is 86.89%; the content of germanium in the arsenic acid iron slag is 0.08 percent, and the loss rate of germanium in terms of slag is 0.99 percent.

(5) Continuously heating the arsenic-removed solution to 80 ℃ by using Na₂SO₃The potential of the solution is reduced to 290 mV; adjusting the pH of the reduced solution to 3.4 by using an aqueous sodium hydroxide solution, continuously introducing alkali, and simultaneously adding H with the mass concentration of 30% by using a peristaltic pump₂O₂Is subjected to oxidation of H₂O₂The amount of Fe in the oxidizing solution is 3g/L²⁺Calculating theoretical amount, and controlling the oxidation time for 1.25 h;

(6) and continuously introducing alkali liquor to the end point pH4.7 after the oxidation is finished, and filtering and separating to obtain a germanium-containing precipitate and a germanium-precipitated liquid. Through detection, the content of germanium in the germanium-containing precipitate is 7.377%, and the germanium precipitation rate of the slag is 89.38%.

Example 3:

the invention discloses a method for separating germanium and arsenic in an acid solution, which has a process flow as shown in figure 1 and comprises the following steps:

(1) in the acid solution, the content of germanium is 0.994g/L, and the content of arsenic is 0.75 g/L;

(2) heating the acid solution to 70 ℃, and adding hydrogen peroxide into the acid solution according to 2.0 time of the theoretical oxidation amount of arsenic in the oxidized acid solution for oxidation to obtain oxidized liquid;

(3) adjusting the pH value of the oxidized solution to 2.4 by using an aqueous solution (with the mass concentration of 32%) of sodium hydroxide, and enabling the solution to generate white precipitates;

(4) and (4) filtering and dehydrating the solution obtained in the step (3) to obtain precipitated slag ferric arsenate and arsenic-removed solution. Detection shows that the arsenic content in the arsenic-removed liquid is 0.058g/L, and the precipitation rate of arsenic is 92.3% in terms of liquid; the content of germanium in the arsenic acid iron slag is 0.1 percent, and the loss rate of germanium in terms of slag is 0.84 percent.

(5) Continuously heating the arsenic-removed solution to 80 ℃ by using Na₂SO₃The potential of the solutionReducing to 270 mV; adjusting the pH of the reduced solution to 3.0 by using an aqueous sodium hydroxide solution, continuously introducing alkali, and simultaneously adding H with the mass concentration of 30% by using a peristaltic pump₂O₂Is subjected to oxidation of H₂O₂The amount of Fe in the oxidizing solution is 4g/L²⁺Calculating theoretical amount, and controlling the oxidation time for 1.5 h;

(6) and continuously introducing alkali liquor to the final pH value of 5.0 after the oxidation is finished, and filtering and separating to obtain a germanium-containing precipitate and a germanium-precipitated liquid. Through detection, the content of germanium in the germanium-containing precipitate is 5.709%, and the germanium precipitation rate of the slag is 86.8%.

Although the present invention has been described with reference to the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but may be embodied or carried out in various forms without departing from the spirit and scope of the invention.