Method for removing iron, aluminum and silicon from nickel-cobalt-manganese-copper solution under normal pressure

Abstract

The invention discloses a method for removing iron, aluminum and silicon from a nickel-cobalt-manganese-copper solution under normal pressure. The method comprises the following steps that 1) a rough nickel-cobalt-manganese-copper raw material is taken and mixed with water to form slurry, then acid and a reducing agent are added for leaching, the pH value at the leaching end point is smaller than or equal to 2.5, and the Fe<2+> content is controlled to be proper; (2) after the leaching slurry is subjected to dense separation, supernate and a precipitator are added, in a parallel flow mode, into liquid which contains nickel, cobalt, manganese and copper without iron, aluminum and silicon at the temperature of 70-100 DEG C, and heat preservation is conducted, wherein the precipitator is a rough nickel-cobalt-manganese-copper raw material with the solid content being 1-50%, and the pH value of the liquid without iron, aluminum and silicon ranges from 3.0 to 4.0; and 3) the slurry is subjected to solid-liquid separation, filtrate is as an extraction stock solution, water is added into removed iron-aluminum-silicon slag and leaching slag to prepare slurry with the solid content being smaller than or equal to 50%, acid is added to regulate the pH value to 2.0-3.5, a reducing agent is added to enable the Fe<2+> concentration to be greater than or equal to 0.1g / L, the removed iron-aluminum-silicon slag and the filtrate are obtained after solid-liquid separation, and the filtrate is fed to a leaching section for leaching raw materials. According to the method, auxiliary materials and hazardous chemicals do not need to be used for removing iron, aluminum and silicon, other elements are not introduced either, the purposes of lowering the cost of the auxiliary materials and the salinity of wastewater are achieved, and the sewage treatment pressure is lowered.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy or chemical industry, in particular to a method for removing iron, aluminum and silicon from nickel-cobalt-manganese-copper acidic solution under normal pressure. Background technique [0002] With the rapid development of new energy vehicles, the society's demand for nickel, cobalt and manganese resources is increasing rapidly. In this context, countries and regions with resource advantages have banned the export of nickel and cobalt raw ore to stimulate the local economy. Become an important raw material for the extraction of nickel, cobalt and manganese. [0003] The technical route of wet extraction of nickel, cobalt and manganese is sulfuric acid leaching + extraction process. Iron, aluminum and silicon often exist in the form of colloids in the water phase, which will cause three phases during the extraction process, affect the extraction mixing efficiency, and cause the degradation of the e...

AI Technical Summary

Problems solved by technology

These methods all have the disadvantages of large consumption of auxiliary materials, high salinity of wastewater, and high cost.

[0005] CN111500862A discloses a method for removing iron and aluminum from mixed nickel-cobalt hydroxide leaching solution, which neutralizes and removes iron with a nickel-based / cobalt-based neutralizer, which solves the problem of high auxiliary material consumption in the iron-removing process

Its essence is iron removal by goethite method. Although it solves the problem of large consumption of precipitant in the iron removal process, and the loss of valuable metals in slag is less than before, there are the following problems: 1. It is necessary to use other auxiliary materials as oxidants ( hydrogen peroxide or manganese dioxide), using hydrogen peroxide as the oxidant, the level of hazardous chemicals is high, and there is a problem of rapid organic oxidation degradation in the back-end extraction, and manganese dioxide is used as the oxidant, which has the problem of increasing the burden of back-end extraction; 2. The iron pH is too high, the amount of slag that needs to be pickled is large, and the treatment is more cumbersome; 3. The oxidation process and the precipitation iron removal process are carried out separately, and there are local over-alkali and local over-oxidation problems, and there are a lot of jelly in the iron removal slag , After the slag is pickled, a large amount of iron and aluminum returns to the system, resulting in the enrichment of iron and aluminum in the system, and in severe cases, the production system is paralyzed; 4. It is only suitable for systems with low total metal ion concentration (total metal ion ≤ 80g / L) , when the total metal ions in the water phase are high (total metal ions > 80g / L), the slag filtration is not good, and the content of nickel, cobalt and manganese is high; 5. The production stability is not good, and the fluctuation is large

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