Technologies of twice dissolved by hydrochloric acid for waste rare earth luminescent materials

摘要

The invention belongs to the field of recycling of resources, in particular to a method for waste rare earth luminescent material by dual hydrochloric acid. First hydrochloric acid was used to dissolve the red phosphor powder (Y₂O₃:Eu) priority, and yttrium-rich rare earth chloride solution and residue were obtained after filtered. Residue's major components were green and blue phosphor powder, and the removal of Ca²⁺ in filtrate was conducted by using Na₂SO₄, and CaSO₄ precipitation separation was conducted to get rich rare earth chloride solution, europium and yttrium. Residue was mixed with alkali to perform alkaline fusion at high temperature to decompose green and blue powder, then sodium aluminate, magnesium, barium and rare earth oxides were obtained. Alkaline fusion products were washed with water, and filtered, and then sodium aluminate solution and residues containing rare earth oxides were obtained.