Purification and cobalt removal method for zinc leaching solution

Abstract

The invention relates to the technical field of hydrometallurgy, in particular to a purification and cobalt removal method for a zinc leaching solution. Zinc leachate is directly electrolyzed under amagnetic field condition, and the magnetic field intensity is accurately controlled and is kept at 7-9A / m, so that the content of cobalt in electrolyzed liquid is greatly reduced, the removal rate ofthe cobalt is improved, the circulation use capability of the electrolyzed liquid is realized, and the cobalt removal difficulty of the zinc leachate is reduced.

Description

technical field [0001] The invention relates to the technical field of hydrometallurgy, in particular to a method for purifying and removing cobalt from a zinc leaching solution. Background technique [0002] The production of metal zinc in my country basically adopts hydrometallurgy, that is, after acid leaching or alkaline leaching of minerals or waste residues such as zinc, to obtain a leaching solution, and then use the leaching solution as an electrolyte to electrolyze zinc. However, the leaching solution contains a large amount of impurities, such as iron, nickel, cobalt, copper, cadmium, arsenic, indium, etc. Among them, cobalt is extremely harmful in the zinc smelting process, and the content of cobalt in the electrolyte exceeds a certain When the amount is too high, it will cause the electrolysis efficiency to drop significantly, and also seriously affect the quality of the electrolytic zinc product. At present, in the hydrometallurgy of zinc, the main method is to...

AI Technical Summary

Problems solved by technology

After the process of replacement and removal of impurities, not only a large amount of zinc powder needs to be consumed, resulting in high processing costs, but also the entry of impurities such as antimony and arsenic, which affects the quality of the final product. A large amount of zinc powder, but it needs to introduce organic components, which will seriously affect the environment, and the difficulty of separating nickel and cobalt will also increase significantly

[0003] Usually, zinc-containing nickel-cobalt waste slag, after sulfuric acid leaching treatment, in the obtained sulfuric acid leach solution, the concentration of zinc ions is as high as 30g / L or more, and at this time the content of nickel ions and cobalt ions is also above 1g / L. Use P 2 0 4 ,P 5 0 7 , C-272 and other phosphorus extractants for separation and extraction, it was found that when the organic phase was subjected to saponification to extract cobalt ions, zinc ions would also be extracted, or even preferably extracted, resulting in an unsatisfactory extraction rate of cobalt ions; and after The study found that the extraction rate of C-272, which has a high selectivity to cobalt ions, is only 80% in time.

In the process of leachate treatment, when chlorination is used for leaching and N235 is used for extraction, zinc will also be extracted as ZnCl 4 2- The form is extracted by N235, making it difficult to separate zinc ions and cobalt ions

[0004] In summary, for the removal of cobalt in the zinc leaching solution, no matter the sulfuric acid leaching or hydrochloric acid leaching is used, it is difficult to separate the zinc and cobalt well by the extraction method.