Patent ID: 9657369
Date: 2017-05-23
CPC Classifications: C22B,Y02P

Claim:
1. A method for recovering substances from monazite slag, comprising the following steps: (i) adding monazite slag into a 0.25 to 0.5 molar solution of inorganic strong acid according to a monazite slag/acid ratio of 1 kg slag/1 to 15 L acid solution to form a mixture, heating the mixture to 40° C.-100° C., stirring the mixture for 5-8 hours, cooling the mixture, standing the mixture to obtain a first supernatant liquid containing uranium, thorium and rare earth elements and a slurry, and recovering the first supernatant liquid; (ii) filtering the slurry to obtain filtration slag and filtrate, and combining the filtrate with the first supernatant liquid obtained in step (i) to obtain a second supernatant; (iii) washing the filtration slag with water, stopping washing when the pH value of a water washing solution is 2-3, and dry-pressing the filtration slag to obtain a water washing solution and a secondary slag; and (iv) combining the water washing solution with the second supernatant liquid obtained in step (ii) to obtain a mixed water solution comprising uranium, thorium and rare earth elements.