Method for precipitating cerium-containing rare-earth carbonate

Abstract

The invention belongs to the technical field of production of rare-earth carbonate, and particularly relates to a method for precipitating cerium-containing rare-earth carbonate. The method comprises the following steps: introducing inactive gas into a cerium-containing rare-earth solution to be precipitated, a precipitant solution and dilution water for solutions to expel dissolved oxygen and air in the precipitation reaction kettle; while stirring, reacting the precipitant solution with the cerium-containing rare-earth solution until the pH value is 6.5-7.5 so as to completely precipitate the rare earth; and dehydrating the precipitate, and washing to obtain the cerium-containing rare-earth carbonate. The acid solubility effect of the cerium-containing rare-earth carbonate is obviously improved, the solution is clear and transparent, and the turbidity is less than 5.0NTU, so the acid solubility effect is similar to that of the product precipitated by the traditional ammonium bicarbonate. The method achieves the effect of enhancing the acid solubility of the cerium-containing rare-earth carbonate, is simpler to operate, and has certain industrial popularization meanings.

Description

technical field [0001] The invention belongs to the technical field of rare earth carbonate production, in particular to a method for precipitating cerium-containing rare earth carbonate. Background technique [0002] Rare earth carbonates containing cerium mainly include cerium carbonate, lanthanum cerium carbonate, lanthanum cerium praseodymium carbonate, and cerium-less rare earth carbonate. They are important raw materials for preparing cerium nitrate, cerium ammonium nitrate, cerium sulfate, catalysts and polishing materials. Cerium carbonate or lanthanum cerium carbonate are acid-dissolved for further use, so their acid solubility is critical. The precipitant commonly used in the preparation of rare earth carbonate is ammonium bicarbonate, and the precipitated cerium carbonate or lanthanum cerium carbonate has large particles, which are easy to precipitate and wash, and have very good acid solubility. Now, due to environmental pressure, to avoid the pollution of ammon...

AI Technical Summary

Problems solved by technology

However, the aqueous solution of sodium carbonate has a high pH, ​​and when it is combined with a cerium-containing rare earth chloride liquid, it is very easy to form Ce(OH) 3 and Ce(OH) 4 , resulting in poor acid solubility of cerium carbonate or lanthanum cerium carbonate. In order to completely dissolve such salts, it is often necessary to add an excessive amount of acid or add a reducing agent such as hydrogen peroxide to aid dissolution, which brings obstacles to the application of such products. lack of market competitiveness

[0003] When sodium carbonate is used as a precipitant to prepare rare earth carbonate, there is no report on the poor acid solubility caused by the appearance of tetravalent cerium hydroxide, and there is no report on the feasible way to solve this problem.