CN109628953B - Method for removing arsenic, antimony and bismuth in copper electrolyte - Google Patents

Abstract

The invention relates to the field of copper electrolyte purification and impurity removal, and provides a method for removing arsenic, antimony and bismuth from a copper electrolyte, aiming at solving the problems of complicated steps, poor effect or high cost and the like of the method for purifying the copper electrolyte and removing the arsenic, antimony and bismuth in the prior art. The method comprises the following steps: 1) adding transition antimony oxide into the copper electrolyte; 2) stirring the copper electrolyte or standing the copper electrolyte for reaction, and filtering to remove precipitates after the reaction is completed. The method has simple operation steps, and can quickly and efficiently remove arsenic, antimony and bismuth in the copper electrolyte; the removal rate of arsenic, antimony and bismuth is high, and antimony can be almost completely removed; the transition antimony oxide can be recycled, and is green and environment-friendly.

Description

A kind of method for removing arsenic, antimony and bismuth in copper electrolyte

technical field

The invention relates to the field of copper electrolyte purification and impurity removal, in particular to a method for removing arsenic, antimony and bismuth from copper electrolyte.

Background technique

The purification and reuse of copper electrolyte has always been an important topic in the copper electrorefining industry, especially with the over-exploitation of copper concentrate, the grade of copper ore decreases, and the accumulation rate of impurities in copper electrolyte increases. At present, this issue plagues China's copper smelting industry. Because pyrometallurgical copper smelting cannot remove many associated elements in copper ore, such as nickel, arsenic, bismuth, antimony, gold and other elements, these impurities either lose electrons and enter the copper electrolyte in the subsequent electrolytic refining process, or directly enter the anode mud. These impurity ions entering the copper electrolyte are continuously enriched with the refining and production of copper. When their concentration reaches a certain level, they will co-deposit with copper in the electrodeposition process and enter the cathode copper, which will reduce the quality of the cathode copper.

At present, the main method used for electrolyte purification is electrolytic induced copper removal, which removes arsenic, antimony, bismuth and other impurities together while electrodepositing copper. The process is widely used, has good impurity removal effect, and has a good industrial foundation. However, it has obvious disadvantages: 1) The use of lead anode plates leads to extremely high pressure in the electrolytic cell and high energy consumption, and the lead plates are easily deformed during use, requiring manual correction, which ultimately leads to cumbersome overall process; 2) In In the final stage of electrolytic copper removal, the toxic and harmful gas arsine is easily produced on the cathode plate, and the working environment of workers is harsh; 3) The black copper, which is the solid product of the cathode, is difficult to use directly, and is generally returned to the copper pyrometallurgical process; 4) The entire purification process includes electricity. Removal of copper, recovery of nickel sulfate, recycling of sulfuric acid, long process flow. In addition, such as ion exchange method, barium salt, lead salt precipitation method is also applied to the purification of copper electrolyte. However, the above methods all have obvious defects and have not been used on a large scale.

On September 10, 2008, the Chinese Patent Office published an invention patent application for a method for purifying and removing impurities from copper electrolyte, with the application publication number CN101260539A. By controlling the relative mass ratio of Sb/Bi in the anode copper to be 0.8-8.0, the concentration of As in the copper electrolyte to be 4.0g/L to 15.0g/L, and the As(III) and As(V) in the copper electrolyte The concentration ratio of arsenic antimonate is 0.01 to 0.15, which accelerates the deposition and precipitation of arsenic antimonate in copper electrolyte, and further improves the self-purification and impurity removal ability of copper electrolyte. However, after the copper electrolyte is purified and removed by this technical solution, the copper electrolyte still contains a relatively high concentration of bismuth element, and the effect of purification and removal of impurities is poor, which cannot meet the one-step purification of the copper electrolyte.

And in Xiao F X,Cao D,Mao J W,et al.Role of Sb(V) in removal of As,Sb and Biimpurities from copper electrolyte[J].Transactions of Nonferrous MetalsSociety of China,2014,24(1):271- 278 also proposed that pentavalent antimony and the harmful elements arsenic, antimony and bismuth in the copper electrolyte have co-precipitation. Therefore, the use of antimony pentoxide as a copper electrolyte purifying agent is very promising for industrial application.

On this basis, on September 15, 2017, the Chinese Patent Office disclosed an invention patent application for a method for precipitation and decontamination of copper electrolyte, with the application publication number CN107164786A. This patent realizes the co-precipitation and removal of arsenic, antimony and bismuth in copper electrolyte by adding antimony compound as precipitant into copper electrolyte. The copper electrolyte can be directly returned to the copper electrorefining system after de-impurification, and the precipitated waste residue containing arsenic, antimony and bismuth is comprehensively recovered by the gradient temperature-controlled fire method. The waste residue is firstly decomposed at low temperature under the protection of inert gas to obtain low temperature decomposition gas and low temperature decomposition residue, and the low temperature decomposition gas is condensed to obtain arsenic compounds; the low temperature decomposition residue is subjected to high temperature decomposition under the atmosphere control to obtain bismuth compounds and high temperature decomposition gas; high temperature decomposition The gas is condensed to obtain antimony compound, which can be used as a precipitant to return to the copper electrolyte precipitation and de-impurification process. In this technical scheme, the added precipitating agent is one or more of antimony trioxide, antimony tetraoxide and antimony pentoxide. However, the antimony compound precipitation agent is prepared by a high-temperature pyrotechnic process, and its composition and structure are difficult to control, the activity of the obtained antimony oxide is low, and the purification effect of the copper electrolyte needs to be improved.

SUMMARY OF THE INVENTION

In order to solve the problems in the prior art of methods for purifying copper electrolyte and removing arsenic, antimony and bismuth with complicated steps, poor effect and high cost, the present invention provides a method for removing arsenic, antimony and bismuth from copper electrolyte. In the method of the invention, the purpose of simplifying steps and efficiently removing arsenic, antimony and bismuth in the copper electrolyte is achieved first, and on this basis, the effect of removing arsenic, antimony and bismuth is improved.

In order to achieve the above objects, the present invention adopts the following technical solutions.

A method for removing arsenic, antimony and bismuth in a copper electrolyte, the method comprises the following steps:

1) adding the transition state antimony oxide to the copper electrolyte;

2) The copper electrolyte is stirred or allowed to stand for reaction, and the precipitate is removed by filtration after the reaction is complete.

The method of the invention adds transitional antimony oxide as a precipitating agent to the copper electrolyte, and the purpose of removing impurities is rapidly realized by reacting or adsorbing or co-precipitating the precipitating agent with three harmful elements of arsenic, antimony and bismuth in the copper electrolyte. The overall method is simple, no other equipment is needed, and only two steps are needed to put in and filter, which is extremely efficient and concise.

Preferably, the transition state antimony oxide in step 1) is a single-phase antimony oxide with a pyrochlore structure in a mixed valence state of Sb(III,V).

A single-phase antimony oxide with a pyrochlore structure in a mixed valence state of Sb(III, V) contains Sb(III) and Sb(V). During the reaction process, the pentavalent antimony released by the transition state antimony oxide and the bismuth element in the copper electrolyte form Bi ₃ SbO ₇ precipitation, and the reaction with arsenic is that pentavalent arsenic As(V) directly reacts with pentavalent antimony Sb(V) forms arsenic antimonic acid and then forms arsenic antimonate precipitation with other trivalent impurity ions, and induces precipitation with antimony element in copper electrolyte by increasing the concentration of antimony. The transition state antimony oxide is formed by calcining the antimony pentoxide fine powder obtained by hydrolysis to reduce part of Sb(V) to trivalent antimony Sb(III), and the formed transition state antimony oxide can form a particle size About 60 ~ 120nm powder. The transition state antimony oxide in this particle size range has a large specific surface area, can be quickly dispersed, and has good effect of reaction precipitation and adsorption co-precipitation, while the particle size is too small to provide the nucleation activity in the co-precipitation process. If the particle size is too large, the specific surface area will be reduced, the contact probability with the impurity components in the copper electrolyte will be reduced, and the dispersion difficulty will be increased. During the self-reduction process, the partial reduction of pentavalent antimony and the loss of crystal water occurred simultaneously in the antimony oxide, so that the transition state antimony oxide powder contained a large number of defects and pores, thus the specific surface area of the transition state antimony oxide was It can be greatly improved, the chance of contact with the copper electrolyte is increased, and the solubility in the copper electrolyte is improved due to the generation of defects, and the antimony concentration of the solution system can be increased in the copper electrolyte in a short time, so as to reduce The purpose of efficiently removing arsenic, antimony and bismuth is achieved.

Preferably, the molar ratio of Sb(III) to Sb(V) in the transition state antimony oxide is (0.3-0.8):2.

Too high content of Sb(III) will lead to a decrease in solubility and crystal defects, and reduce the proportion of active ingredient Sb(V), resulting in a decrease in the effect of removing arsenic, antimony and bismuth, while too little content of Sb(III) cannot effectively form Defects and porosity also reduce the removal of arsenic, antimony and bismuth.

Preferably, the solid-to-liquid ratio of the transition state antimony oxide used in step 1) and the copper electrolyte is: (5-35) g: 1L.

The removal of arsenic, antimony and bismuth in the copper electrolyte can be realized with only a small amount, and the adsorbed transition state antimony oxide can be recovered and reused.

Preferably, the reaction temperature in step 2) is 25-80°C.

The removal of arsenic, antimony and bismuth in copper electrolyte with transition state antimony oxide as a purifying agent can be carried out at least in the extremely large temperature range of 10 to 95 °C. In the range of 25 to 80 °C, the reaction rate is fast and the reaction proceeds. It is relatively complete, with few or even no side reactions, and the optimal reaction temperature is 60 °C.

Preferably, the copper electrolyte can also be replaced with any acidic water body.

The method of the invention can be used for removing arsenic, antimony and bismuth in acidic water, and all have better application effects.

The beneficial effects of the present invention are:

1) The operation steps are simple, and the arsenic, antimony and bismuth in the copper electrolyte can be removed quickly and efficiently;

2) The removal rate of arsenic, antimony and bismuth is high, and the antimony element can be almost completely removed;

3) The transition state antimony oxide can be recycled and reused, which is green and environmentally friendly.

Description of drawings

Fig. 1 is the TEM image of the transition state antimony oxide used in the embodiment of the present invention;

FIG. 2 is the XPS energy spectrum of the transition state antimony oxide used in the embodiment of the present invention.

Detailed ways

The present invention will be further described and described in detail below with reference to specific embodiments and accompanying drawings. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention referred to in the following description are generally only a part of the embodiments of the present invention, not all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Unless otherwise specified, the raw materials used in the examples of the present invention are commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the embodiments of the present invention are conventional methods mastered by those skilled in the art.

Example 1

Using antimony trichloride and hydrochloric acid as raw materials, the solid-to-liquid ratio is 1kg: 3L, mixing to obtain a mixed solution, and feeding chlorine gas with 2 times the molar amount of antimony trichloride into the mixed solution, and after aeration, the mixed solution is mixed with 80 times the amount of chlorine. Volume parts of water were mixed with water at 25°C for hydrolysis and aging for 6h, then filtered, and the filtered crystalline solid was calcined. The calcination temperature was 300°C, the calcination time was 5h, and the heating rate was 5°C/min , and then the transition state antimony oxide with an average particle size of about 117 nm was obtained. The transition state antimony oxide was detected, where the molar ratio of Sb(III) to Sb(V) was 0.3:2.

The transition state antimony oxide was added to the low-impurity copper electrolyte at a solid-to-liquid ratio of 5g: 1L, and the copper electrolyte was detected by standing at 80°C for 30 minutes of reaction. The copper electrolyte composition before and after purification is shown in Table 1.

Table 1 Composition of copper electrolyte before and after purification

Example 2

Using antimony trichloride and hydrochloric acid as raw materials, the solid-to-liquid ratio is 1kg: 3L, mixing to obtain a mixed solution, and feeding chlorine gas with 2 times the molar amount of antimony trichloride into the mixed solution, and after aeration, the mixed solution is mixed with 80 times the amount of chlorine. Volume parts of water were mixed with water at 25°C for hydrolysis and aging for 6h, then filtered, and the filtered crystalline solid was calcined. The calcination temperature was 350°C, the calcination time was 6h, and the heating rate was 10°C/min , and then the transition state antimony oxide with an average particle size of about 72 nm was obtained. The TEM image of the transition state antimony oxide prepared in this example is shown in FIG. 1 , and the XPS image is shown in FIG. 2 . According to Figure 1, we can find that the transition state antimony oxide prepared in this example has an extremely rich mesoporous structure, which increases its specific surface area. From Figure 2, we can calculate that the molar ratio of Sb(III) to Sb(V) in the transition state antimony oxide is 0.7:2.

The transition state antimony oxide was added to the low-impurity copper electrolyte at a solid-to-liquid ratio of 15g:1L, and the reaction was stirred at 20rpm for 30min at 25°C to detect the copper electrolyte. The copper electrolyte composition before and after purification is shown in Table 2.

Table 2 Composition of copper electrolyte before and after purification

Example 3

Using antimony trichloride and hydrochloric acid as raw materials, the solid-to-liquid ratio is 1kg: 3L, mixing to obtain a mixed solution, and feeding chlorine gas with 2 times the molar amount of antimony trichloride into the mixed solution, and after aeration, the mixed solution is mixed with 80 times the amount of chlorine. The volume part of water was mixed with water at 25°C for hydrolysis and aging for 6h, then filtered, and the filtered crystalline solid was calcined. , and then a transition state antimony oxide with an average particle size of about 95 nm was obtained.

The transition state antimony oxide was added to the copper electrolyte with high impurity content at a solid-to-liquid ratio of 35g: 1L, and the copper electrolyte was tested at 60°C for 30 minutes of standing reaction. The copper electrolyte composition before and after purification is shown in Table 3. The molar ratio of Sb(III) to Sb(V) in the transition state antimony oxide was 0.6:2.

Table 3 Copper electrolyte composition before and after purification

Example 4

Using antimony trichloride and hydrochloric acid as raw materials, the solid-to-liquid ratio is 1kg: 3L, mixing to obtain a mixed solution, and feeding chlorine gas with 2 times the molar amount of antimony trichloride into the mixed solution, and after aeration, the mixed solution is mixed with 80 times the amount of chlorine. The volume parts of water were mixed with water at 25°C for hydrolysis and aging for 6h, then filtered, and the filtered crystalline solid was calcined. , and then the transition state antimony oxide with an average particle size of about 97 nm was obtained. The transition state antimony oxide was detected, where the molar ratio of Sb(III) to Sb(V) was 0.5:2.

The transition state antimony oxide was added to the copper electrolyte with high impurity content at a solid-to-liquid ratio of 35g:1L, and the reaction was stirred at 600rpm for 30min at 60°C to detect the copper electrolyte. The copper electrolyte composition before and after purification is shown in Table 4.

Table 4 Copper electrolyte composition before and after purification

Example 5

Using antimony trichloride and hydrochloric acid as raw materials, the solid-to-liquid ratio is 1kg: 3L, mixing to obtain a mixed solution, and feeding chlorine gas with 2 times the molar amount of antimony trichloride into the mixed solution, and after aeration, the mixed solution is mixed with 80 times the amount of chlorine. The volume parts of water were mixed with water at 25°C for hydrolysis and aging for 6h, then filtered, and the filtered crystalline solid was calcined. , and then the transition state antimony oxide with an average particle size of about 96 nm was obtained. Transition state antimony oxides were tested in which the molar ratio of Sb(III) to Sb(V) was 0.8:2.

The transition state antimony oxide was added to the copper electrolyte with high impurity content at a solid-to-liquid ratio of 20 g: 1 L, and the reaction was stirred at 20 rpm for 30 min under the condition of 60 °C, and the copper electrolyte was detected. The copper electrolyte composition before and after purification is shown in Table 5.

Table 5 Copper electrolyte composition before and after purification

It can be clearly seen from Table 1 to Table 5 in the above-mentioned Examples 1 to 5 that the method of the present invention has excellent use effect for removing arsenic, antimony and bismuth from copper electrolyte, and the purified copper electrolyte fully satisfies the copper electrolytic refining process. The requirement of preparing high-purity cathode copper realizes one-step purification of impurity-containing copper electrolyte.

Claims (5)

1. The method for removing arsenic, antimony and bismuth from the copper electrolyte is characterized by comprising the following steps:

1) adding transition antimony oxide into the copper electrolyte;

2) stirring the copper electrolyte or standing the copper electrolyte for reaction, and filtering to remove precipitates after the reaction is completed;

the transition state antimony oxide is prepared by the following processes: antimony trichloride and hydrochloric acid are used as raw materials, and the solid-liquid ratio is 1 kg: and 3L, mixing to obtain a mixed solution, introducing chlorine gas with the molar weight 2 times that of antimony trichloride into the mixed solution, mixing the mixed solution with 80 times of water by volume after introducing the chlorine gas, hydrolyzing and aging at 25 ℃ for 6 hours, filtering, calcining the filtered crystalline solid, controlling the calcining temperature to be 300-350 ℃, the calcining time to be 5-6 hours, and the calcining temperature rise rate to be 5-10 ℃/min, and then preparing the transition state antimony oxide with the average particle size of 72-117 nm.

2. The method for removing arsenic, antimony and bismuth in copper electrolyte according to claim 1, wherein the transition antimony oxide in step 1) is a single-phase antimony oxide with pyrochlore structure of mixed valence of trivalent antimony and pentavalent antimony.

3. The method for removing arsenic, antimony and bismuth in the copper electrolyte according to claim 2, wherein the molar ratio of trivalent antimony to pentavalent antimony in the transition state antimony oxide is (0.3-0.8): 2.

4. the method for removing arsenic, antimony and bismuth in the copper electrolyte according to claim 1, wherein the solid-to-liquid ratio of the transition state antimony oxide and the copper electrolyte used in the step 1) is as follows: (5-35) g: 1L of the compound.

5. The method for removing arsenic, antimony and bismuth in the copper electrolyte according to claim 1, wherein the reaction temperature in the step 2) is 25-80 ℃.

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