Method for selectively precipitating and separating cobalt in potential-control manner

Abstract

The invention provides a method for selectively precipitating and separating cobalt in a potential-control manner. Copper-cobalt-manganese slag is used for neutralizing a copper-cobalt-manganese solution to a required pH value; then, sodium sulphide is added under the condition of simultaneously controlling the solution potential and the pH value to perform vulcanization copper removal; after the copper removal, sodium ethylxanthate is added under the condition of simultaneously controlling the solution potential and the pH value to perform precipitation cobalt removal; after the cobalt removal, sodium sulphide is added into the solution under the condition of simultaneously controlling the solution potential and the pH value to perform vulcanization zinc removal; after the zinc removal, sodium carbonate is added in the solution for neutralizing and producing manganese carbonate. The method practically realizes the stepped precipitation and separation of the copper, the cobalt and the zinc in the solution through simultaneously controlling the metal ion mixed potential and the pH value in the solution; particularly, the cobalt content in the cobalt precipitate products reaches more than 20.0 percent; the processes are closely associated; the single process cannot reach the expected effect of the stepped separation of valuable metal.

Description

technical field [0001] The invention relates to a hydrometallurgical process in the field of nonferrous metallurgy, in particular to a hydrometallurgical method using potential-controlled selective precipitation to separate cobalt. Background technique [0002] Cobalt is a steel-gray metal with metallic luster. Its excellent physical properties determine its wide application in cemented carbide, heat-resistant alloy, lithium-ion battery cathode material and pigment industry. However, my country's cobalt resources are very scarce, and it has long relied on importing cobalt ore from countries such as Congo (Kinshasa) and Zambia, which are rich in cobalt resources. implementation, cobalt ore needs to be smelted into copper-cobalt alloy by electric furnace for export, so copper-cobalt alloy replaces cobalt ore and becomes an important cobalt raw material in the Chinese market. Here comes the difficulty. [0003] The classic process of extracting cobalt from cobalt ore is: cobalt...

AI Technical Summary

Problems solved by technology

Although this method can realize the selective separation of manganese and nickel, adding a large amount of ammonium salt changes the solution system and brings great difficulties to the subsequent treatment of the solution.

[0007] At present, the most common method used in industry is to use the alkali neutralization method of sodium carbonate to produce a large amount of black copper-cobalt-manganese slag, referred to as copper-manganese slag, of which mainly carbonates of metals such as copper, zinc, iron and manganese Due to its difficulty in utilization, most enterprises can only stack it at present, which not only easily causes secondary pollution, but also causes waste of valuable metals

Some researchers have proposed to recover valuable metals in copper-manganese slag. The usual method is to dissolve them with hydrochloric acid or sulfuric acid, and then use iron powder replacement or neutralization precipitation to recover part of the copper. Although part of the valuable metals can be recovered, the separation The effect is still unsatisfactory, facing the same problem as copper cobalt manganese liquid treatment

[0008] The development of these methods can realize the recovery of valuable metals in the copper-cobalt-manganese solution, but there are some defects that restrict its industrial application, such as high treatment cost, long process flow and difficult wastewater treatment, so in the copper-cobalt-manganese solution The effective separation and recovery of valuable metals is still an urgent problem in this field

Liu Weifeng et al. (A method for separating valuable metals in solution by controlled potential vulcanization, application number: 201610030160.X, application date: 2016-01-18) proposed to use controlled potential vulcanization to separate valuable metals in copper-cobalt-manganese solution. Use the controlled potential sulfidation method to remove copper from the copper-cobalt-manganese solution and produce copper sulfide concentrate, then use the controlled potential sulfidation method to precipitate all cobalt and zinc in the form of sulfide from the copper-removed solution, and finally use neutralization Manganese carbonate slag is produced by precipitation by the method. Although this method realizes the effective separation of copper and cobalt-zinc in the copper-cobalt-manganese solution, the cobalt and zinc in the solution are precipitated in the form of sulfide at the same time after copper removal, which brings great difficulties to the subsequent separation and extraction. great difficulty

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