Method for separation of rare earth in calcium-containing rare earth solution by precipitation

Abstract

The invention discloses a method for separation of rare earth in a calcium-containing rare earth solution by precipitation. The calcium-containing rare earth solution in which the rare earth concentration ranges from 0.1 mol / L to 1.5 mol / L, the calcium ion concentration ranges from 0.1 mol / L to 1.0 mol / L, the molar ratio X of the rare earth and calcium is more than or equal to 0.7 and less than orequal to 8.0 is adopted, the rare earth in the calcium-containing rare earth solution is precipitated by bicarbonate salt, and the conditions such as temperature, pH, feeding speed in the precipitation process are adjusted and controlled according to the size of the molar ratio of the rare earth and the calcium in the solution, and the concentration of bicarbonate in the solution is adjusted to control the stability of calcium bicarbonate and the supersaturation of rare earth carbonate, so that rare earth ions precipitate to form the crystalline rare earth carbonate; and calcium ions form thesoluble calcium bicarbonate, the efficient separation of the rare earth and the calcium in the calcium-containing rare earth solution is achieved, and rare earth oxide with the purity greater than 98% is obtained.

Description

technical field [0001] The invention relates to the field of rare earth hydrometallurgy, in particular to a method for separating rare earth and calcium by precipitation. Background technique [0002] Due to their unique physical and chemical properties, the compounds formed by rare earth elements have very rich magnetic, optical, electrical, catalytic and other functional properties, and are known as "vitamins of modern industry" and "treasure house of new materials". In the process of rare earth hydrometallurgy, the separation of rare earth and calcium is often encountered; for example, the rare earth concentration in the lanthanum-calcium or lanthanum-cerium-calcium feed solution produced by the rare earth extraction and separation workshop using the calcium saponification process is generally 0.5-1.5mol / L, the calcium ion concentration is 10g / L-40g / L; the rare earth concentration in the leaching solution of bastnaesite concentrate is 0.1-0.7mol / L, and the calcium ion co...

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Problems solved by technology

It can play a catalytic role in the presence of rare earths. It is difficult to convert calcium carbonate into calcium bicarbonate through carbon dioxide carbonization, and the solubility of calcium bicarbonate is not high and unstable. If there is a large amount of calcium carbonate, it cannot be well realized. Separation of calcium rare earth

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