公开(公告)号：EP3325679A1

公开(公告)日：2018-05-30

申请号：EP16763441.9

申请日：2016-07-18

申请人： Kronos International, Inc.

发明人： KLAUSET, Jan ,  RUUD, Oystein ,  DAHL, Asborn ,  MEDVED, Mitja ,  THOEN, Per ,  PIERAU, Thomas

IPC分类号： C22B3/08 ,  C22B3/22 ,  C22B34/12 ,  C22B3/44

CPC分类号： C22B34/125 ,  C01G23/0532 ,  C01G49/14 ,  C22B3/22 ,  C22B3/44 ,  C22B34/1259 ,  Y02P10/234

摘要： The invention relates to the method step of reducing trivalent iron in the production of titanium dioxide according to the sulfate method. According to the invention, after the removal of the poorly soluble decomposition residue, the reduction occurs by means of metallic iron in such a way that the trivalent iron is completely reduced to divalent iron and tetravalent titanium is partially reduced to trivalent titanium in a deliberate manner. A Ti(III) content of 1 wt% to 5 wt% with respect to the total titanium is preferably sought. The method step according to the invention preferably occurs in continuous operation at a temperature of > 50°C to 2 product quality is achieved.