Hydrometallurgical treatment of titaniferous iron material

Claim 1

METHOD FOR PREPARING A SUBSTANTIALLY IRON-FREE TITANIUM OXIDE MATERIAL BY REACTING IN A PRESSURE VESSEL A MIXTURE OF TITANIFEROUS IRON MATERIAL CONTAINING FERRIC IRON VALUES, SULFURIC ACID, ORGANIC FLOTATION AGENT, AND REDUCING MATERIAL WHICH COMPRISES THE STEPS OF: HEATING SAID MIXTURE IN SAID PRESSURE VESSEL WHILE MAINTAINING THE PRESSURE WITHIN SAID PRESSURE VESSEL IN THE RANGE OF FROM ABOUT 500 P.S.I. TO ABOUT 2000 P.S.I. FOR A PERIOD OF TIME SUFFICIENT TO PRODUCE SOLUBILIZED IRON VALUES IN SAID MIXTURE AND DIRECTLY CONVERT THE TITANIUM VALUES TO SUBSTANTIALLY IRON-FREE, RELATIVELY INSOLUBLE HYDRATED TITANIUM DIOXIDE, SAID REDUCING MATERIAL BEING PRESENT IN AT LEAST THE THEORETICAL AMOUNT REQUIRED TO REDUCE ALL OF SAID FERRIC IRON VALUES TO FERROUS IRON VALUES, AND SAID SULFURIC ACID BEING PRESENT IN AN AMOUNT SUFFICIENT TO REACT WITH THE FERROUS IRON VALUES FORMED FROM SAID FERRIC IRON AND ANY ADDITIONAL FERROUS IRON VALUES IN SAID MIXTURE, AND THEREAFTER SEPARATING SAID SOLUBILIZED IRON VALUES FROM SAID INSOLUBLE, HYDRATED TITANIUM DIOXIDE.