RU2237750C1 - Method for electrolytic refining of copper and nickel from copper/nickel alloys - Google Patents

Abstract

FIELD: nonferrous metallurgy.

SUBSTANCE: method of refining copper and nickel from copper/nickel alloys containing precious metal admixtures comprises electrochemical dissolution of anodes of copper/nickel alloy and precipitation of copper to form nickel solution and pulp. Dissolution of anodes is effected in diaphragm-separated anode space within suspended pulp medium.

EFFECT: reduced power consumption (by 10%) and increased gold level in pulp.

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Description

The invention relates to the metallurgy of non-ferrous metals and can be used in enterprises for the production of copper, nickel and other metals and their compounds from alloys, in particular gold.

The following methods of electrorefining metals.

- Nickel anodes composition,%: Ni 89-92; Cu 4-5; Re 1.0-3.5; C 1.0-1.2; 8 0.8-2.0; From 0.1-0.3 are subjected to electrolytic refining at a current density of 200-250 A / m ² for 4-5 days. The temperature of the solution should be in the range of 55-65 ° С (Baimakov Yu.V., Zhurin A.I. Electrolysis in hydrometallurgy. - M.: Metallurgizdat, 1963, pp. 289-388).

- Electrolytic refining of nickel, including the electrochemical dissolution of anodes in a sulfate-chloride electrolyte with a concentration of chlorine ions of 60-65 g / l with a copper content of anodes of 16-23% (USSR Author's Certificate No. 1397541).

- There is a method in which an electrolyte for the electrorefining of copper, containing sulfuric acid, copper sulfate, chlorine ions, thiourea and glue, to improve the quality of surface copper, reduce its impurities and reduce energy consumption, additionally contains fluorinated quaternary ammonium salt (Copyright certificate USSR No. 1592398).

The disadvantages of these methods are:

1. Loss of precious metals in the sludge.

2. Increased power consumption.

A known method of electrolytic dissolution of copper, carried out in solutions containing CuSO ₄ 5H ₂ O from 120-180 g / l and 120-200 g / l H ₂ SO ₄ and gold. The anodes are cast plates of red copper, the cathodes are thin sheets of electrolytic copper. The distance between the axes of the electrodes of the same name is 40-50 mm, the current density of 160-250 A / m ² . Electrolysis is carried out at a temperature of 55-65 ° C for 7-8 days under conditions of electrolyte circulation (Baymakov Yu.V., Zhurin A.I. Electrolysis in hydrometallurgy. - M.: Metallurgizdat, 1963, p. 144) .

However, this method has the following disadvantages:

- increased power consumption,

- sludge settles quickly and does not enter into electrochemical reactions, due to which, accordingly, the concentration of precious metals in the sludge decreases.

A known method of refining copper and nickel from copper-nickel alloys, adopted as a prototype (Baymakov Yu.V., Zhurin A.I. Electrolysis in hydrometallurgy - M .: Metallurgizdat, 1963, p. 213, 214). The method consists in the electrolytic dissolution of anodes from a copper-nickel alloy, the deposition of copper to obtain a Nickel solution and sludge. The fusion of the alloy is carried out at a current density of 100-150 a / m ² and a temperature of 50-65 ° C. The current density is limited by diffusion kinetics and depends on the concentration of salts of other metals in the solution. The alloy contains about 70% copper, 30% nickel and up to 0.5% of other metals, in particular gold.

The disadvantage of this method is the high energy consumption and loss of precious metals, in particular gold contained in the alloy.

The technical results of the invention are:

1. Reduced energy consumption.

2. Increasing the gold content in the sludge.

The technical result is achieved by the fact that in the method of electrolytic refining of copper and nickel from copper-nickel alloys containing impurities of precious metals, which consists in the electrochemical dissolution of anodes from a copper-nickel alloy, the deposition of copper to produce a nickel solution and sludge, according to the invention, the electrochemical dissolution of the anodes is carried out in the anode space separated by the diaphragm, in the suspended layer of sludge.

The method is implemented as follows.

In the electrolytic bath, the copper-nickel anode is placed in a mesh diaphragm. Under the influence of electric current, the anode begins to dissolve, copper is deposited on the cathode, nickel goes into solution, and particles of sludge fall down. A gas reagent is brought to the bottom of the bath, providing a suspended state of the sludge, and a “fluidized bed” is formed. An inert gas is chosen as the gas reagent, which ensures the “boiling” of the layer, preventing the sludge from rapidly precipitating, and thereby facilitates the entry of the sludge into the electrochemical reaction, which increases the concentration of gold in the sludge.

The optimality of the distinguishing features is as follows.

- The Cu ₂ O film formed on the surface of the anode is peeled off by a “fluidized bed” of sludge, the diffusion potential of a clean metal surface decreases, as a result, the current efficiency increases and the specific energy consumption decreases.

- Cu ₂ O is in suspension, it enters into chemical interactions, more non-ferrous metals (copper and nickel) go into solution, and the content of gold and other precious metals increases accordingly. The above is confirmed by the following examples shown in the table.

Thanks to the proposed method, a reduction in energy consumption of 10% is achieved and the concentration of gold and other precious metals in the sludge is increased by 1.5-2 times.

Claims (1)

The method of electrolytic refining of copper and nickel from copper-nickel alloys containing impurities of precious metals, which consists in the electrochemical dissolution of anodes from a copper-nickel alloy, deposition of copper to produce a nickel solution and sludge, characterized in that the anodes are dissolved in the anode space separated by a diaphragm, in a suspended slurry layer.