Method for recovering rare earth from rare earth-containing aluminum-silicon materials

Abstract

The invention relates to a method for recovering rare earth from rare earth-containing aluminum-silicon materials, which comprises the following steps: taking the rare earth-containing aluminum-silicon materials including rare earth-loaded molecular sieves, catalyst wastes, and the like as raw materials, conducting prioritized selective leaching by acid so as to lead the majority of the rare earth and a small amount of aluminum to be dissolved and separated from silicon and other impurities, leading the rare earth to form precipitates and be separated from the aluminum by adopting a double salt precipitation or oxalate precipitation method, and then recovering and purifying the rare earth. The method has the advantages of directly realizing the extraction of the rare earth from the aluminum-silicon materials including the molecular sieves and the like, with over 98% purity of the obtained rare earth, and avoiding impurities such as aluminum, silicon and the like entering the rare earth; and meanwhile, the technology also has the characteristics of little fixed investment, low production cost and easiness for realizing industrialized production.

Description

technical field [0001] The invention relates to a method for recovering rare earths from aluminum-silicon materials containing rare earths, which belongs to the field of recycling rare earth resources. Background technique [0002] As a high-tech element, rare earths are widely used in the field of catalysts. In the 1960s, rare earth-Y type molecular sieves were widely used in heavy oil catalytic cracking, and then rare earths were also used in other molecular sieve catalysts. At present, the domestic consumption of rare earths in the field of petrochemical catalysis accounts for more than 10% of the total consumption of rare earths, and tens of thousands of tons of rare earths are used in the petrochemical industry every year in the world. [0003] With the increasing shortage of resources, the recovery of valuable rare earth components from the petrochemical catalyst preparation process or catalyst waste has good social and economic benefits. Chinese patent CN1686813 dis...

AI Technical Summary

Problems solved by technology

Chinese patent CN1686813 discloses a method for preparing polyaluminium chloride by using waste molecular sieve catalysts, which can recycle aluminum in waste materials, but this patent does not involve the recovery of high-priced rare earth elements

According to Chinese patent CN1686813 and experimental research, the aluminum element in the molecular sieve waste has high activity and is easy to dissolve in the direct acid leaching process. Rare earth and aluminum have the characteristics of co-dissolution, which not only consumes a large amount of acid for leaching, but also for subsequent impurity removal and single rare earth extraction. Separation brings great trouble

[0006] For rare earth wastes containing aluminum and silicon, such as fluorescent powder wastes, rare earths and materials with low aluminum dissolution activity, there is also a process for extracting rare earths by alkaline treatment in China. Patent CN200810029417.5 proposes a similar method. Alumina raw material has applicability, but there are problems of long process and low yield of rare earth