Method for recovering rare earth, aluminum and silicon from rare earth-containing aluminum-silicon waste

Abstract

The invention provides a method for recovering rare earth, aluminum and silicon from rare earth-containing aluminum and silicon waste. The method comprises: S1, acid leaching the rare earth-containing aluminum-silicon waste with an aqueous inorganic acid solution to obtain silicon-rich slag and an acid leaching solution containing rare earth and aluminum ions; S2, adding Alkaline substances and control the pH value of the pickling solution to 3.5 to 5.2, solid-liquid separation to obtain aluminum hydroxide-containing precipitates and rare earth-containing filtrates; S3, use aluminum hydroxide-containing precipitates to react with sodium hydroxide to obtain metaaluminic acid Sodium solution and aluminum silicon slag, and use the filtrate containing rare earth to prepare rare earth compound products. In the above method, aluminum and rare earth are dissolved with acid, and then by segmental alkali conversion, aluminum ions are precipitated to obtain aluminum hydroxide and rare earth ions are separated, and then excessive sodium hydroxide is added to convert aluminum hydroxide into sodium metaaluminate solution to realize Rare earth and aluminum are efficiently recycled at the same time, and the amount of sodium hydroxide is greatly reduced, which reduces the cost of recycling.

Description

technical field [0001] The invention relates to the field of rare earth recovery, in particular to a method for recovering rare earth, aluminum and silicon from rare earth-containing 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 cracki...

AI Technical Summary

Problems solved by technology

[0005] The main purpose of the present invention is to provide a method for recovering rare earth, aluminum and silicon from rare earth-containing aluminum-silicon waste to solve the technical problems of high recovery cost and low recovery efficiency in existing methods