CN111996395A

CN111996395A - Method for deep purification and arsenic removal of indium back extraction solution

Info

Publication number: CN111996395A
Application number: CN201911289680.2A
Authority: CN
Inventors: 王亚杰; 朱挺健; 刘军
Original assignee: Qinghai Western Indium Co ltd
Current assignee: Qinghai Huaxin Renewable Resources Co ltd
Priority date: 2019-12-16
Filing date: 2019-12-16
Publication date: 2020-11-27

Abstract

The invention provides a method for deeply purifying and removing arsenic from indium back extraction solution, which comprises the following steps: the indium back extraction solution contains In more than or equal to 80 g/L and H⁺≥100 g/L（HCL）、Fe²⁺≥10 g/L、As³⁺The concentration is approximately equal to 2-3 g/L; adding H into indium back extraction solution₂O₂Making Fe²⁺Oxidation to Fe³⁺(ii) a Adding gasified liquid ammonia into the obtained oxidation liquid until the pH value of the system is adjusted to 2.8 to obtain a neutralization solution; adding KMnO into the neutralized liquid obtained in the step (3)₄Obtaining a purified solution by using the solution; filtering the deep purification liquid obtained in the step to obtain deep purification liquid and purification slag; the deep purification liquid is sent to electrolysis, and the purification slag is returned to the zinc hydrometallurgy leaching system. The liquid ammonia neutralized acid after the purification arsenic removal method provided by the invention is gasified replaces NaOH neutralized acid used in the traditional process to remove impurities, so that the cost is reduced, and a foundation is laid for the next step of refined indium electrolysis.

Description

Method for deep purification and arsenic removal of indium back extraction solution

Technical Field

The invention belongs to the field of rare metal metallurgy, and particularly relates to a method for deeply purifying indium back extraction solution and removing arsenic.

Background

Indium is a silvery white fusible dilute metal. Soft and can be scored on the nail. Good ductility, no work hardening phenomenon during pressure processing, and can be rolled into extremely thin sheets. Indium itself has cold weldability and the indium supply blocks are coated with grease. Indium is similar in chemical nature to iron. Is not easy to oxidize at normal temperature, can burn in red heat, and can be dissolved in inorganic acid. No separate deposit of indium has been found, which is associated in trace amounts with minerals such as zinc, tin, etc. When the content reaches a few ten-thousandth, the zinc blende has industrial production value, and is mainly extracted from the zinc blende at present. In addition, indium can be recovered from waste residues and smoke dust generated in the production of zinc, lead and tin. The existing indium recovery method mainly comprises the following steps: extraction, reduction, membrane separation, and the like. The production of arsenic and antimony in the process of recovering indium by an extraction method directly influences the quality of sponge indium, but the traditional iron-arsenic-antimony coprecipitation removes arsenic and antimony, the dosage of ferrous sulfate heptahydrate is very large, the reaction temperature is high, the cost is high, the generated iron-arsenic-antimony coprecipitate has low stability, and the removal rate of arsenic and antimony is low.

In the prior art, crude indium is produced by adopting a metal zinc-aluminum displacement method in an indium back extraction solution, and the method is simple. However, the method has a great safety risk, and produces the virulent arsenic hydride in the replacement process, so that a plurality of replacement procedure workers are poisoned by the arsenic hydride in China every year, and a large amount of virulent arsenic hydride gas is discharged to the environment in the production process, which is a common difficulty in indium production. And the treatment of the solution after the replacement is difficult.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for deeply purifying and removing arsenic from indium back extraction solution.

In order to achieve the purpose, the technical scheme of the invention is as follows:

an indium stripping solution deep purification and arsenic removal method comprises the following steps:

(1) the indium back extraction solution contains In more than or equal to 80 g/L and H⁺≥100 g/L（HCL）、Fe²⁺≥10 g/L、As³⁺≈2-3 g/L；

(2) Adding H into indium back extraction solution₂O₂Making Fe²⁺Oxidation to Fe³⁺Obtaining an oxidation liquid;

(3) adding gasified liquid ammonia into the oxidation liquid obtained in the step (2) until the pH value of the system is adjusted to 2.8, and obtaining a neutralization solution;

(4) adding KMnO into the neutralized liquid obtained in the step (3)₄Obtaining a purified solution by using the solution;

(5) filtering the purified liquid obtained in the step (4) to obtain deep purified liquid and purified slag; the deep purification liquid is sent to electrolysis, and the purification slag is returned to the zinc hydrometallurgy leaching system.

Further, in the step (2), the hydrogen peroxide is added in an amount of Fe in the solution²⁺Oxidation to Fe³⁺1.1-1.5 times of the theoretical dosage of the catalyst, and the reaction time after adding the hydrogen peroxide is 0.5-1 h.

Further, in the step (3), the liquid ammonia is used until the pH value of the system is 2.8, the temperature is 80 ℃, and the end-point pH value is kept stable for 20-50 min.

Further, KMnO in step (4)₄The concentration of the solution was 10%, KMnO₄The addition amount of the solution is 10-20mL per liter of neutralized solution.

Further, the deep purification liquid obtained in the step (5) contains more than or equal to 80 g/L of indium, Cl < - > approximately equals to 210 g/L, and NH₄ ⁺60 g/L, total Fe content less than or equal to 20 mg/L, AS content less than or equal to 20 mg/L.

Has the advantages that: the liquid ammonia neutralized acid after the purification arsenic removal method provided by the invention is gasified replaces NaOH neutralized acid used in the traditional process to remove impurities, so that the cost is reduced, and a foundation is laid for the next step of refined indium electrolysis.

Drawings

FIG. 1 is a block diagram of a process for preparing the present invention.

Detailed Description

The invention is illustrated below with reference to specific examples. It will be understood by those skilled in the art that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

An indium stripping solution deep purification and arsenic removal method is shown in figure 1 and comprises the following steps:

（2）Adding H into indium back extraction solution₂O₂Making Fe²⁺Oxidation to Fe³⁺The hydrogen peroxide is added in an amount of Fe in the solution²⁺Oxidation to Fe³⁺1.1-1.5 times of the theoretical dosage of the catalyst, and the reaction time after adding the hydrogen peroxide is 0.5-1 h to obtain an oxidation solution;

(3) adding gasified liquid ammonia into the oxidation liquid obtained in the step (2) until the pH value of the system is adjusted to 2.8 and the temperature is 80 ℃, and maintaining the end-point pH stable for 20-50 min to obtain a neutralization liquid;

(4) adding KMnO with the concentration of 10% into the neutralized liquid obtained in the step (3)₄Solution, KMnO₄The addition amount of the solution is 10-20mL per liter of neutralized solution, and purified solution is obtained;

(5) filtering the deep purification liquid obtained in the step (4) to obtain deep purification liquid and purification slag; the deep purification liquid is sent to electrolysis, and the purification slag is returned to the zinc hydrometallurgy leaching system.

The test is carried out on 100 groups of test samples, and the comprehensive result shows that the components of the obtained deep purification liquid are that indium is more than or equal to 80 g/L, Cl < - > is approximately equal to 210 g/L, and NH₄ ⁺60 g/L, total Fe content less than or equal to 20 mg/L, AS content less than or equal to 20 mg/L.

Test and test:

1. test samples: an indium back-extraction solution produced In a certain extraction method recovery process is taken, and the main components of the indium back-extraction solution are In: 91g/L, As: 3g/L, Fe: 12g/L, HCl: 110 g/L; 1L of it is taken and used as a hydrochloric acid system.

2. The purification and arsenic removal method comprises the following steps: 30g of H was added to the indium back-extraction solution₂O₂Making Fe²⁺Oxidation to Fe³⁺And the reaction time is 0.7h, thus obtaining an oxidation solution; adding gasified liquid ammonia until the pH value of the system is adjusted to 2.8 and the temperature is 80 ℃, and maintaining the end-point pH value stable for 35min to obtain a neutralized liquid; then KMnO was added at a concentration of 10%₄Obtaining a purified solution by using 14mL of the solution; filtering the obtained deep purification liquid to obtain deep purification liquid and purification slag; the deep purification liquid is sent to electrolysis, and the purification slag is returned to the zinc hydrometallurgy leaching system.

3. Detection of purified sample

The components of the deep purification liquid are 89 g/L of indium and 197 g of Cl-197 g/L，NH₄ ⁺20 g/L, total Fe 18 mg/L, AS11 mg/L.

Claims

1. The method for deeply purifying and removing arsenic from indium stripping solution is characterized by comprising the following steps:

2. The method of claim 1, wherein the hydrogen peroxide is added in an amount of Fe in the solution in step (2)²⁺Oxidation to Fe³⁺1.1-1.5 times of the theoretical dosage of the catalyst, and the reaction time after adding the hydrogen peroxide is 0.5-1 h.

3. The method for deep purification and arsenic removal of indium back extraction solution according to claim 1, wherein the amount of liquid ammonia used in the step (3) is adjusted to a system pH of 2.8 and a temperature of 80 ℃, and the final pH is maintained stable for 20-50 min.

4. The method for deep purification and arsenic removal of indium strip solution as claimed in claim 1, wherein KMnO is used in step (4)₄The concentration of the solution was 10%, KMnO₄The addition amount of the solution is 10-20mL per liter of neutralized solution.

5. The method for deep purification and arsenic removal of indium back extraction solution according to claim 1, wherein the deep purification solution obtained in the step (5) comprises the components of indium more than or equal to 80 g/L, Cl < - > about 210 g/L, and NH₄ ⁺60 g/L, total Fe content less than or equal to 20 mg/L, AS content less than or equal to 20 mg/L.