A kind of preparation method of high colloidal cerium glue

Abstract

The invention belongs to the technical field of rare earth compound preparation, and particularly relates to a preparation method of cerium glue with high glue forming performance. According to the method, firstly, soluble cerium salt is prepared into a cerous nitrate or cerium chloride solution; hydrogen peroxide is used as an oxidizing agent; ammonium hydroxide is used as a precipitant; throughtransformation, cerium hydroxide precipitates are obtained; the cerium hydroxide precipitates are heated to the temperature of 85 to 100 DEG C; the state is maintained for 30 to 90 min; the materialsare washed until the electric conductivity is less than 5 ms / cm; plate frame press filtering is performed; cerium hydroxide paste is obtained; the cerium hydroxide paste and monobasic acid are pulpedinto glue; drying is performed to obtain a primary cerium glue product; the primary cerium glue product is dissolved into a solution with the cerium ion concentration being 0.2 to 0.6 mol / L through adding deionized water; then, ammonia water precipitation is performed; after the materials are washed until the electric conductivity is less than 5 ms / cm, plate frame press filtering is performed to obtain cerous hydroxide paste; monobasic acid is added for pulping to obtain glue; drying is performed to obtain a product. The dissolution degree of the prepared cerium glue product prepared by the invention can reach 350 g / L or higher (the content of rare earth oxide); the product can be applied to the production process requiring high-concentration tetravalent cerium solution.

Description

technical field [0001] The invention belongs to the technical field of preparation of rare earth compounds, and in particular relates to a preparation method of high colloid-forming cerium colloid. Background technique [0002] As a new source of tetravalent cerium, cerium glue is easy to use, soluble in water, and the content of impurity anions in its aqueous solution is low. It can be used as an additive for color TV fluorescent screens, and can change the toughness, strength and other optical properties of fluorescent glass. The market It is in great demand; it is used in the preparation of automobile exhaust gas purification catalysts, which can partially replace precious metals due to its unique OSC effect; it can also be used in glass decolorization clarifiers, etc., and has a broad market. [0003] Chinese patents CN101633516A and CN103910373A both adopt the hydrogen peroxide oxidation method to prepare cerium hydroxide with good purity and nitric acid solubility. Ho...

AI Technical Summary

Problems solved by technology

However, the preparation mechanism of CN101633516A is to precipitate and then oxidize to generate cerium hydroxide. The preparation process needs to add a dispersant and a rare earth accelerator, and the production operation is complicated; CN103910373A adopts the method of first precipitating and then oxidizing, and the product needs to be treated with 3-4N ammonia water. solution, to wash away the nitrate in the solution, and the requirements for washing with water are high

[0004] Cerium rubber products are generally obtained by mixing cerium hydroxide paste with a basic acid and then drying. However, the cerium rubber products obtained in this way generally have low solubility and are suitable for the preparation of precision membrane materials with low concentrations of tetravalent cerium solutions. It is not applicable to the production process that requires a higher concentration of tetravalent cerium

[0005] For the purification and catalysis of automobile exhaust, a higher concentration of tetravalent cerium is generally required, and the cerium gel prepared directly by adding cerium hydroxide to acid cannot meet the requirements of use, which requires cerium gel products with high gelation performance