METHOD FOR SEPARATING AND EXTRACTING RARE EARTH AND REGENERATED RARE EARTH POLISHING POWDER FROM WASTE RARE EARTH POLISHING POWDER

摘要

The present invention relates to a method for separating and extracting rare earth and regenerated rare earth polishing powder from waste rare earth polishing powder. The method is characterized by comprising: first using a primary acid leaching-alkali fusion-secondary acid leaching combined treatment process to separate and extract rare earth in waste rare earth polishing powder to obtain a rare earth chloride leaching solution; then using ammonia water for precipitation and impurity removing, and using hydrochloric acid for acidolysis to obtain a purified rare earth chloride solution; then, using a rare earth chloride solution obtained by means of coprecipitation of hydrofluoric acid, an ammonium bicarbonate solution, and a dispersing agent to obtain cerium lanthanum fluorocarbonate powder; and finally, by means of drying, two-stage high-temperature calcination, and ball milling, obtaining the regenerated rare earth polishing powder having good polishing performance. According to the present invention, the total leaching rate of the rare earth in the waste rare earth polishing powder reaches 95% or above, the total recovery rate of the rare earth reaches 93% or above, and efficient separation, extraction and recycling of the rare earth in the waste rare earth polishing powder are achieved.