Method for efficiently oxidizing and synchronously removing iron and cobalt from nickel electrolysis anolyte and preparing magnetic material

Abstract

The invention discloses a method for synchronously removing iron and cobalt from nickel electrolysis anolyte and preparing a magnetic material, wherein the method comprises the following steps: introducing gas containing an oxidant into the nickel electrolysis anolyte to obtain a reaction liquid, adjusting the pH value of the reaction liquid to be greater than or equal to 3, controlling the reaction potential of the first-stage reaction liquid to be less than or equal to 0.3 V, and carrying out first-stage reaction; then adjusting the reaction potential of the second-stage reaction liquid to be greater than or equal to 1.0 V, and carrying out second-stage reaction; and after the second-stage reaction is completed, obtaining oxidized liquid and oxidizing slag, roasting the oxidizing slag, and thus obtaining the magnetic material. Compared with the prior art, the method has the advantages that the iron and cobalt removal rate is high and reaches 99% or above, the iron content in the iron and cobalt removed liquid is 1 ppm or below, the cobalt content is 2 ppm or below, and the concentration is far lower than the enterprise production requirement concentration, the nickel loss is small, the impurity purification effect is good, the technological process is short, impurity ions are not added into the nickel liquid, and a pure nickel electrolysis catholyte and the iron-cobalt-nickel ternary magnetic material can be obtained; and the product quality is stable and the economic benefit is high.

Description

technical field [0001] The invention belongs to the technical field of nickel electrolysis anolyte recovery and utilization, in particular to a method for efficiently oxidizing and synchronously removing iron and cobalt from nickel electrolysis anolyte to prepare a magnetic material. Background technique [0002] In the production process of electro-nickel, iron-cobalt is the main impurity element in the nickel electrolyte, and its content directly affects the quality of the product. The deep purification of iron and cobalt in nickel electrolyte has always been a "stuck neck" problem restricting the development of nickel metallurgy industry. [0003] At present, most enterprises adopt multi-stage purification process of iron removal, copper removal and cobalt removal. Among them, yellow sodium iron vanadium method and neutralization hydrolysis method are generally used to remove iron, and the liquid after iron removal is sent to the oxidation and cobalt removal process afte...

AI Technical Summary

Problems solved by technology

Although the extraction method can deeply separate nickel and cobalt, it introduces an organic extractant, which is prone to emulsification and forms a third phase that affects product quality. At the same time, the equipment cost is high and the operation is complicated, which is not conducive to the downstream production process; the electrode potential of nickel and cobalt is similar , so if the electrode potential is not properly controlled in the process of oxidation and decobaltization, it will often be accompanied by the loss of nickel

[0005] All in all, the current iron and cobalt removal process has disadvantages such as large amount of slag, difficult filtration, long process, complicated operation, and low economic benefits of externally paid products

At the same time, the oxidized cobalt removal residue contains 32-35% nickel and 11% cobalt. More nickel is brought out after cobalt removal, and the primary utilization rate of resources is low.

At present, enterprises choose acid-soluble separation and purification of nickel and cobalt in the treatment of oxide slag instead of recycling iron. On the one hand, the treatment process is long, the operation is complicated, and the equipment investment cost is high. On the other hand, the iron oxide cobalt slag has not been effectively utilized.

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