Recovery method of rare earth elements in NdFeB (neodymium iron boron) waste materials

Abstract

The invention discloses a recovery method of rare earth elements in NdFeB (neodymium iron boron) waste materials, belonging to the technical field of recovering of rare earth resource. The recovery method comprises the following steps: (1) evenly mixing aluminum fluoride powder and cryolite powder according to the mass ratio of 1:1-1:10, to obtain a cryolite-aluminum fluoride mixture; (2) crushing the NdFeB waste materials into granules with granule size of 4-6mm and burying into the cryolite-aluminum fluoride mixture; (3); putting cryolite-aluminum fluoride mixture with buried NdFeB waste materials into an electric furnace and reacting for 3-12h at the temperature of 900-1200 DEG C; and (4) conducting solid-liquid separation to the product obtained after reaction to obtain solid residue and fused salt respectively, wherein the solid residue is waste steel, and the fused salt is a rare earth fluoride-cryolite-aluminum fluoride mixture. The unoxidized rare earth elements in the NdFeB waste materials can be selectively extracted through aluminum fluoride, rare earth oxidized into oxides can be better dissolved by cryolite, and therefore the recovery rate of rare earth can be greatly improved.

Description

technical field [0001] The invention relates to the technical field of recovery of rare earth resources and clean utilization of secondary resources, in particular to a method for recovery of rare earth elements in NdFeB waste. Background technique [0002] Due to its superior magnetic properties, NdFeB permanent magnet materials have been widely used in the fields of national defense, aerospace, medical equipment, computers, electronics and new energy automobile industries. China is a major producer of NdFeB, with an output of about 100,000 tons in 2012, and its annual output is still showing a high-speed growth trend. During the production and processing of NdFeB, about 30% of its own weight waste is produced, and the NdFeB permanent magnet contained in the product also enters the environment in the form of waste after the product is scrapped. Rare earth is an important strategic resource. The content of rare earth elements in NdFeB magnets is about 30%, of which neodymiu...

AI Technical Summary

Problems solved by technology

Although this method overcomes the disadvantages of the wet method, the treatment process is cumbersome, the operation is difficult to control, the equipment requirements are high, and the oxidized rare earths in the waste cannot be recovered, resulting in a low final rare earth recovery rate of this method

So far, when recycling NdFeB waste, an efficient and non-environmentally polluting treatment process has not been developed