Preparation method of crystalline rare-earth carbonate

Abstract

The invention relates to a preparation method of crystalline rare-earth carbonate. According to the scheme, the method comprises the following steps: selecting ion absorpt deposit and carrying out an in-situ leaching method, wherein the in-situ leaching method comprises the following steps: preparing a mixed leaching agent with the mass fraction being 2% by using two ammonium salts which are in a mass ratio of (1-4) to 1, adding an aluminum inhibitor which is 0.05% of mass of the mixed leaching agent, stirring evenly, and then carrying out in-situ leaching according to a liquid-solid ratio of (0.1-2) to 1; after the leaching solution completely seeps, adding top wash ore which is 10% of mass of the leaching agent, collecting the leaching solution, clarifying, and adding a precipitator, wherein the mass ratio of the precipitator to the leaching solution is (0.1-0.5) to 1; fully stirring for over 30 minutes, and standing and ageing for 6-24hours; filtering, washing sediment twice with clear water, filtering again, and baking at 110 DEG C, so as to obtain the crystalline rare-earth carbonate, wherein the recovery rate is 70-85%, and the purity is 90-95%. The crystalline rare-earth carbonate is prepared from easily available raw materials and is low in cost, high in recovery rate and high in product purity.

Description

technical field [0001] The invention relates to a new process method for in-situ leaching of rare earth carbonate in the field of hydrometallurgy, in particular to a preparation method of crystalline rare earth carbonate. Background technique [0002] my country is a country with a large reserve of rare earth carbonate resources, as well as a major country in the production, application and export of rare earth carbonate products. Rare earth carbonate has the characteristics of improving the elasticity, toughness and strength of metals. It is an important part of jet aircraft, missiles, engines and heat-resistant machinery, and can also be used as a protective shell for radiation protection. Rare earth carbonates are mainly derived from weathering crust leaching type rare earth deposits, which have the characteristics of wide distribution, mostly in hilly areas, low grade, and fine ore particle size. Rare earth carbonates are mainly adsorbed on clay minerals with hydrated io...

AI Technical Summary

Problems solved by technology

The second is to use ammonium bicarbonate as a precipitant to precipitate rare earths, but no matter whether oxalic acid is used as a precipitant or ammonium bicarbonate is used as a precipitant, there are impurities such as iron, aluminum, and calcium contained in the rare earth leaching solution, which makes the obtained The quality of rare earth products is unqualified

Especially impurity Al 3+ When ammonium bicarbonate precipitates rare earths, aluminum also forms flocs and precipitates at the same time, resulting in low purity of rare earth products, and Al 3+ Hydrolysis produces colloidal aluminum hydroxide, which reduces the crystallization active area and makes it difficult to form crystalline rare earth carbonate

If impurities are removed in the leaching solution, this will not only increase the operating procedures of the process, but also cause loss of rare earths during the impurity removal process