Patent ID: 6051196
Filing Date: 2000-04-18
Classification: C01F,C22B

Abstract:
A method for purifying a phosphorus containing scheelite ore comprising:contacting a scheelite ore comprising scheelite, apatite, and calcite phases with a volume of dilute hydrochloric acid to form a calcium containing solution and a calcite-depleted ore, the dilute hydrochloric acid having a concentration sufficient to dissolve the calcite phase without substantially dissolving the apatite phase;separating the calcium containing solution from the calcite-depleted ore;contacting the calcite-depleted ore with a volume of a concentrated hydrochloric acid to form a phosphorus containing solution and a scheelite containing residue, the concentrated hydrochloric acid having a concentration sufficient to dissolve the apatite phase;separating the scheelite containing residue from the phosphorus containing solution.