公开(公告)号：US20230220516A1

公开(公告)日：2023-07-13

申请号：US17927232

申请日：2021-05-18

Applicant: COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION

Inventor： Goutam Kumar DAS

IPC: C22B34/12 ,  C22B3/22 ,  C22B3/42 ,  C22B21/00 ,  C22B34/22 ,  C22B3/10 ,  C22B26/22 ,  C22B47/00 ,  C22B3/44

CPC classification number: C22B34/1245 ,  C22B3/22 ,  C22B3/42 ,  C22B21/0015 ,  C22B34/22 ,  C22B3/10 ,  C22B26/22 ,  C22B47/00 ,  C22B3/44

Abstract: A process for recovering titanium dioxide from a titanium-bearing material, the process including the steps of: leaching the titanium-bearing material in a first leaching step at atmospheric pressure and at a temperature of 70 to 97° C. with a first lixiviant to produce a first leach solution comprising undissolved first leach solids that include a titanium content and a first leach liquor, the first lixiviant comprising hydrochloric acid at a concentration of less than 23% w/w; separating the first leach liquor and the undissolved first leach solids; leaching the first leach solids in a second leaching step at atmospheric pressure and at a temperature of 60 to 80° C. with a second lixiviant in the presence of a Fe powder reductant to produce a second leach solution comprising undissolved second each solids and a second leach liquor that includes a leached titanium content and iron content, the second lixiviant comprising a mixed chloride solution comprising less than 23% w/w hydrochloric acid and an additional chloride selected from alkali metal chlorides, magnesium chloride and calcium chloride, or mixtures thereof; separating the second leach liquor and the undissolved second leach solids; and thereafter separating the titanium dioxide and the iron content from the second leach liquor by precipitation, and regenerating the second lixiviant for recycle to the second leaching step.