New Process of Aluminum Removal from Waste Rare Earth Aluminate Trichromatic Phosphors

The rare earth solution obtained by alkali fusion and acid leaching of waste rare earth aluminate trichromatic phosphors usually includes high content aluminum.Therefore,sodium or potassium organic salt selective precipitation method was presented to purify the solution,and the effects were investigated of solution pH,initial aluminum content,temperature and selective precipitant dosage on aluminum removal.Experimental results show that under the conditions of initial rare earth solution pH higher than 2.8,room temperature and atmospheric pressure and precipitant dosage more than 1.3times the theoretical amount,the concentration of residual aluminum in the solution is less than 0.22g/L,aluminum removal efficiency reaches 98.6%,and rare earth loss rate is only 0.83%.