Technology for preparing cobalt hydroxide from cobaltous sulfate solution

Abstract

The impurity content of cobaltous sulfate solution obtained after preliminary purification is high, and the conventional method is to sediment metals of cobalt and the like by using sodium salt. Because the alkalinity of the sodium salt is high and partial over-alkali occurs easily, a large proportion of impurities in the solution also form sediments and the cobalt content in finished cobalt hydroxide products is reduced. The invention provides a technology for preparing cobalt hydroxide from cobaltous sulfate solution, which is characterized by the following steps of carrying out first cobalt sedimentation on cobaltous sulfate solution by using cobalt hydroxide in a first cobalt sedimentation channel; processing the first cobalt sedimentation slurry obtained after the reaction by using a cobalt sedimentation buffer channel, then returning 30 to 50% of the obtained slurry to the first cobalt sedimentation channel, and carrying out filter pressing on the rest slurry; drying filter cakes obtained by filter pressing to obtain the dried cobalt hydroxide which is the finished products; and finally carrying out second cobalt sedimentation on the filtrate by using magnesium hydroxide. in the invention, the partial over-alkali is avoided and the cobalt content of cobalt sediments is increased because the magnesium hydroxide slurry of weak alkalinity is used as a precipitant.

Description

technical field [0001] The invention relates to a cobalt precipitation process in the cobalt hydrometallurgy industry, in particular to a process for preparing cobalt hydroxide from a cobalt sulfate solution of a copper-cobalt ore leaching liquid. Background technique [0002] The wet smelting of copper-cobalt concentrate is generally carried out under the sulfuric acid system to leach valuable metals such as Co and Cu in the ore into the solution, and the solution is initially purified to remove impurities such as Cu, Fe, Al and Si. , to obtain relatively pure cobalt sulfate solution. The cobalt sulfate solution obtained through preliminary purification has high impurity content, and the common way to deal with them is to use sodium salt (NaOH or NaCO 3 ) Precipitate cobalt and other metals, and the precipitates are dried and used as raw materials for further processing, and further purified to obtain high-purity cobalt salts, cobalt oxides and other products. [0003] Se...

AI Technical Summary

Problems solved by technology

[0003] Selecting sodium salt as precipitating agent has the following problems: 1) the waste water obtained by precipitating cobalt liquid can not be returned to the system for reuse due to high sodium content, and can only be treated as sewage discharge, resulting in waste of water resources, and environmental damage

2) The alkalinity of sodium salt is relatively high, and it is easy to form local over-alkali, so that most of the impurities in the solution also form precipitates and enter into the precipitation of cobalt hydroxide, such as: metal Mn, etc., causing hydroxide Reduction of Cobalt Content in Cobalt Finished Products

3) Sodium salts, especially NaOH, have poor filtration performance of precipitated products, long filtration time and low filtration efficiency

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