Method for depositing rare earth cerium (IV)

Abstract

The invention relates to a method for depositing rare earth tetravalent cerium (IV), which is characterized by comprising the following steps of: adding a rare earth feed liquid into a reaction kettle; stirring and heating the rare earth feed liquid to a temperature of between 75 and 85 DEG C; adding H2O2 into the feed liquid in a mol ratio of 50 to 60 percent of the total amount of rare earth oxide in the feed liquid; after 10 to 15 minutes, quickly adding an ammonium bicarbonate solution of 80 to 100 g / l into the feed liquid until the pH of the feed liquid is between 7 and 8; cooling the mixture, standing and clarifying the mixture for 1 to 2 hours; extracting a supernatant fluid and the feed liquid with dregs respectively; and filtering the feed liquid, wherein the rare earth feed liquid is CeCl3 or Ce(NO3)3, the pH is between 5 and 6, and TREO is 50 to 200 g / l. The deposit of cerium hydroxide [Ce(OH)4] in the method is loosening and is easy to wash, and if the raw material is the CeCl3, the deposit can be washed until Cl- is less than 100 ppm, and the production cost is low.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy and relates to a precipitation method of rare earth tetravalent cerium. Background technique [0002] In hydrometallurgy, the methods of cerium hydroxide precipitation mainly include traditional method and alkali conversion method, both of which use cerium carbonate as the main raw material. At present, traditional methods are used in the synthesis of cerium hydroxide at home and abroad. The traditional method uses nitric acid as a solvent, hydrogen peroxide as an oxidizing agent, and ammonia water as a neutralizing agent, and the precipitate is difficult to wash. The alkali conversion method uses sodium hydroxide as the conversion reagent and hydrogen peroxide as the oxidant. Its main advantage is that it saves acid. Because the conversion reaction is a solid-liquid reaction, the reaction speed is slow, so the synthesis cycle is longer and the energy consumption is higher. At the same time, the o...

AI Technical Summary

Problems solved by technology

The alkali conversion method uses sodium hydroxide as the conversion reagent and hydrogen peroxide as the oxidant. Its main advantage is that it saves acid. Because the conversion reaction is a solid-liquid reaction, the reaction speed is slow, so the synthesis cycle is longer and the energy consumption is higher. At the same time, the oxidation rate of cerium is low (<90%), and the uniformity of the product is poor

[0003] Zhong Xueming proposed in ("Journal of Process Engineering" 2005, 5 (1): 74-77) that after the conversion of cerium carbonate to acetic acid, NaOH and H 2 o 2 Preparation of cerium hydroxide, the method is feasible, but the cost is too high, and the precipitation is difficult to wash