Preparation method of low-impurity-entrainment lanthanum carbonate or cerium lanthanum carbonate

Abstract

The invention relates to a preparation method of low-impurity-entrainment lanthanum carbonate or cerium lanthanum carbonate. The preparation method is characterized in that a lanthanum carbonate or cerium lanthanum carbonate solution is taken as a feed solution, an ammonium bicarbonate solution is taken as an ammonium bicarbonate, and new water or carbon precipitation supernatant is left at the bottom of a precipitation reaction kettle to serve as a base solution. The preparation method comprises the following steps: adding lanthanum carbonate or cerium lanthanum carbonate seed crystal in which seed crystal REO (Rare Earth Oxide) to feed solution REO is 1 percent by weight to 10 percent by weight; adding rare earth chloride and the ammonium bicarbonate solution into a reaction kettle at the same time at 20-50 DEG C to carry out a precipitation reaction, wherein the adding rate ratio is 1:1-3:1; at the end of the reaction, performing solid-liquid separation and water washing to obtain a carbonate lanthanum or cerium lanthanum carbonate product. The preparation method has the advantages that the process parameters of feeding way, relative feeding rate, precipitation pH value and final pH value of a ammonium bicarbonate precipitation lanthanum carbonate or cerium lanthanum carbonate solution are adjusted, so that manganese, copper and the like do not undergo the precipitation reaction, and the formed carbonate lanthanum or cerium lanthanum carbonate product has the characteristics of less soft agglomeration, small crystalline grain size and less entrainment of manganese and copper impurities.

Description

technical field [0001] The invention relates to a method for preparing low-impurity entrained lanthanum carbonate or lanthanum-cerium carbonate, which belongs to the field of hydrometallurgy. Background technique [0002] In the high-temperature roasting and decomposition process of concentrated sulfuric acid for rare earth concentrate, during the removal of impurities in sulfuric acid and the conversion to rare earth chloride extraction, industrial magnesium oxide is used as a neutralizer and saponification agent, resulting in impurities such as manganese and copper in the mixed rare earth chloride feed solution The content is high. After the mixed rare earth chloride is separated into a single rare earth, the manganese dioxide content in the lanthanum chloride or lanthanum cerium chloride solution reaches 0.2~0.7g / L, and the copper oxide content is 5~30mg / L, resulting in carbonic acid after ammonium bicarbonate precipitation. Impurities such as manganese and copper in lan...

AI Technical Summary

Problems solved by technology

It is also possible to use this technology to cause cerium oxidation loss

In addition, copper impurities in the rare earth chloride solution are often removed by sulfide precipitation technology. During the production process of this technology, highly toxic gas hydrogen sulfide with the smell of rotten eggs will be released, which is harmful to the human body.

At the same time, these methods have increased the process links, thereby increasing the processing cost