Method for reducing content of potassium in alumina

Abstract

The invention relates to a method for reducing the content of potassium in alumina. The method is characterized by comprising the following steps: (1) adding a potassium removing agent into alumina with high content of potassium, and performing aging, agitation leaching, washing and baking treatment processes to obtain alumina containing low content of potassium or hardly containing potassium; (2) preparing a side product after potassium in alumina is subjected to evaporation concentration and crystallization enrichment. According to the method, the content of potassium in alumina can be reduced to less than 0.1 percent, so that high-efficiency production of electrolytic aluminum can be facilitated; furthermore, the process does not have pollution, has the characteristics of simple treatment process, low cost, large scale and the like, and is easy for automation.

Description

technical field [0001] The invention relates to the fields of metallurgy and chemical industry, in particular to the field of metallurgy, and removes potassium from aluminum oxide, a raw material used in electrolytic aluminum plants, so as to ensure electrolytic aluminum production under high current efficiency. Background technique [0002] In recent years, in the process of electrolytic aluminum production in my country, the current efficiency of some electrolytic aluminum plants has been lower than 90% for a long time, seriously affecting the normal production of electrolytic aluminum. After investigation of various reasons, it was found that the potassium content in the raw material alumina used is relatively low High, normally less than 1% potassium in the alumina, and up to 3% potassium in the alumina used in these problem tanks. Since the atomic radius of potassium is larger than that of sodium, its penetration damage to the carbon cathode increases, and its presence w...

AI Technical Summary

Problems solved by technology

Since the atomic radius of potassium is larger than that of sodium, its penetration damage to the carbon cathode increases, and its presence will lead to a decrease in the conductivity of the electrolyte, which may lead to a decrease in the current efficiency of the electrolyzer

However, due to the high potassium content in certain ores, alumina production enterprises did not pay attention to the existence of this problem. Therefore, the potassium content of the product alumina was not controlled during the alumina production process, and due to the Complexity, it is relatively difficult to control the potassium content in this link, it is recommended to carry out simple treatment on the finished alumina to achieve the purpose of removing potassium, the research on this problem has not yet been published.