SU876792A1 - Method of regenerating copper electrolyte - Google Patents

Description

one

This invention relates to hydrometallurgy, in particular to the electro-refining of copper.

Methods are known for maintaining a given composition of the electrolyte based on the removal of a part of the solution from the main circulation, or by electrolysis in regenerative baths with insoluble anodes tl.

In the case of withdrawal of the solution, the required electrolyte is maintained by adding sulfuric acid, thereby dissolving the electrolyte in the main component. In regenerative baths, the amount of sulfates in the electrolyte is reduced only by copper electroplating, while all interfering impurities completely remain in the electrolyte. In addition, insoluble anodes reduce the capacity of the shop, they release gases, which is a source of pollution of the atmosphere of the shop;

There is also known a method of electrolyte regeneration by electrolysis, with insoluble anodes using anion exchange membranes. According to this method, a part of the electrolyte is subjected to electrolysis in an electrolyzer with anodic cathode spaces separated by an anion-exchange membrane. The electrolyte is cathode-de-mixed and acidified due to the transfer of sulphate ions through the membrane. The regenerated acid returns to electrowaxing 2.

The disadvantages of the method are a decrease in the performance of the electrolyte shop due to the use of

10 insoluble anodes, deterioration of the atmosphere of the workshop due to the evolution of gases.

The closest to the present invention is a method for regenerating copper electrolyte in regenerative baths,

15, which includes extraction from the electrolyte of copper and nickel by electrolysis into a cell bounded by cation and anion exchange membranes.

The disadvantages of the method are a decrease in the productivity of the workshop due to the use of insoluble anodes and the deterioration of the atmosphere of the workshop due to the evolution of gases.

The purpose of the invention is to increase the productivity of the electrolyte shop, to improve working conditions.

The goal is achieved by the fact that in the method of regeneration i copper electrolyte in regenerative

30;: baths, including extraction from the electrolyte of copper and nickel by electrodialysis in a cell bounded by a cation and anion exchange membrane and using anodes from blister copper, the cell for electrodialysis is located between the anode and the cathode, the current density on the membranes is maintained within 250-300 A / m 7a a solution containing 130-150 g / l of sulfuric acid is fed to the metal extraction cell. The method is carried out as follows. Separated from the circular electrolyte, the space between the membranes of the cation exchanger from the anode side and the anion exchanger from the cathode serves a solution containing 130-150 g / l of sulfuric acid, where the ions of copper and nickel are transferred through the cation exchanger through the electric current and sulphations, as a result, a solution of copper and nickel sulphates is formed in the cell, practically free of arsenic and antimony. The optimum current density, which ensures sufficient transfer of copper and nickel, is from 250-300 A / m. Preliminary experiments have shown that, in acidic solutions, to a current density of meme. At 150 A / m, weak metal transfer was observed. The cathodic and anodic processes of the electro-refining of copper are not disturbed. Transfer of honey and nickel through membranes / carried out with an acidity of the electrolyte 120180 g / l. And with these acidities, the transfer rate of copper and nickel, t. Their current output, increases with increasing current density. An increase in the current density above 300 A / m is not possible due to the possible formation of precipitates of metal hydroxides on the membranes. The voltage on the bath is not less than that in the regenerative baths. The recycled electrolyte, with a reduced sulphate content, is mixed with the main circulation of the electrolyte shop. To prevent sludge particles from entering the pores of the membrane, they are wrapped around the filter cloth. Example 1. Experimental verification of the method is carried out in an apparatus whose chambers are separated by anion-cation and anion-exchange membranes, types MK-40 and MA-40. The anode is black copper, the cathode is cathode copper. A 500 ml electrolyte is circulated through the electrode chambers. The volume of the middle chamber is 100 ml. current current on membranes is 250 A / m, on electrodes - 150 A / m, E 1.95 V. Composition electrolyte, g / l: copper 45.2; nickel 20.4} mouse 6.5; antimony 0.5 and sulfuric acid 122.1 circulating through the electrode chambers, after passing 5 Ah of electricity, has the composition, g / l: copper 44.3, nickel 16.8; mouse 6.5, antimony, we 0.5 and sulfuric acid 125.2. At the same time, an average chamber, the initial composition of which is 145.3 g / l of sulfuric acid, contains, g / l: copper 39.5} nickel 16.8 and sulfuric acid 104. The mouse and antimony are not detected in this chamber. Example 2. The current density on the membranes is 300 A / m, E 2.08 V. The table shows the initial and final compositions of the electrolyte and the middle chamber.

45.2

- 20.4

6.5

0.5

126.2

122.1

Thus, the use of anodes from blister copper, instead of lead, increases the efficiency of the electrolytic furnace 4b by 2-3% (the number of regenerative baths) without increasing the consumption of electricity.

Growth of shop productivity, without increasing power consumption, / 45

141.6

43.2 18.1

15.9 Not detected

"

Not detected 113.7

leads to an increase in the economic efficiency of the electrorefining process.

Claims (3)

1.Baymakrv Yu.V., Zhurin A.I. Electrolysis in hydrometallurgy. M., Metallurgists, 1977, pp.57-65. . 2.RZH 11L268, 1974. 3. USSR author's certificate according to application code 2647398, cl. C 25 C 1/12, o 1978