Recycling method of rare earth in aluminum silicon waste

Abstract

The invention discloses a recycling method of rare earth in aluminum silicon waste. The recycling method comprises the following steps that S1, aluminum silicon waste and a sodium hydroxide solution are subjected to a reaction and are filtered after the reaction, and alkali leaching liquid and slag containing rare earth are obtained; and S2, the slag containing the rare earth and an inorganic acid aqueous solution are subjected to a reaction and are filtered after the reaction, and rare earth dip leaching liquid and silicon-rich slag are obtained. Various rare earth compound products are prepared through postprocessing or separation and purification of the rare earth leaching liquid. Aluminum in the aluminum silicon waste and sodium hydroxide form a soluble aluminum-contained solution firstly, and the rare earth is left in the filter residue, so that rare earth and aluminum inside the waste are effectively separated and recycled. Meanwhile, a large amount of aluminum in the aluminum silicon waste is subjected to alkaline leaching and filtered to obtain a valuable sodium metaaluminate solution; when acid is added to the slag containing the rare earth for dissolution, a large amount of acid consumed for dissolution of aluminum is reduced; aluminum in the rare earth leaching solution is greatly reduced; the difficulty of subsequent separation of rare earth and aluminum is simplified; therefore unit consumption of chemical materials is greatly reduced and the recycling cost is reduced.

Description

technical field [0001] The invention relates to the field of rare earth recycling, in particular to a method for recycling rare earths in aluminum and silicon waste. Background technique [0002] Rare earth is a general term for 17 elements including lanthanides, scandium and yttrium. The application fields of rare earth elements are very wide, and can be used to prepare fluorescent materials, rare earth metal hydroxide battery materials, electric light source materials, permanent magnet materials and catalytic materials. With the increasing application of rare earth elements in various fields, the consumption of rare earth elements is also increasing. [0003] Rare earth is an indispensable strategic resource for the development of high-tech industries and the transformation of traditional industries. It is recovered from the waste residue generated in the production process of rare earth molecular sieves, waste petroleum cracking catalysts (waste FCC catalysts) and some o...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims to provide a method for recovering rare earths from aluminum-silicon waste, so as to solve the problem of high recovery cost of rare earths in the prior art