Process for producing titanium tetrachloride

In a process for producing titanium tetrachloride from an iron-titanium ore wherein said ore is subjected to a leaching step where, in a digestion zone, said ore is leached, at elevated temperatures, with a leach liquor containing hydrochloric acid to produce a solid phase of upgraded titanium-containing material and a spent liquid phase containing dissolved metal chlorides;

• a first separation step wherein said solid phase and said spent liquid phase are separated;
• an acid regeneration step where, in an acid regeneration zone, the metal chlorides dissolved in the spent liquid phase are reacted at elevated temperatures in the presence of air and water to produce hydrochloric acid;
• a chlorination step where, in a chlorination zone, said separated solid phase is chlorinated in the presence of a carbonaceous reducing agent at elevated temperatures to produce a product stream containing a titanium tetrachloride phase and an entrained solids phase, said entrained solids phase containing metal chlorides, unreacted upgraded titanium-containing material and unreacted reducing agent and a second separation step wherein said titanium tetrachloride phase is separated from said entrained solids phase, the improvements which comprise:
• combining said entrained solids phase with a liquid mdium consisting of water or leach liquor containing hydrochloric acid and additional iron-titanium ore to dissolve said metal chlorides in said medium and to suspend said unreacted titanium-containing material and unreacted reducing agent in said medium;
• separating said liquid medium into a liquid phase containing dissolved metal chlorides and a solid phase containing unreacted titanium-containing material and unreacted reducing agent from the chlorination product stream;
• recovering chlorine values from said dissolved metal chlorides in said liquid phase as hydrochloric acid by reaction of said metal chlorides in said acid regeneration zone;
• and
• recovering titanium values from said unreacted titanium-containing material and unreacted reducing agent in said solids phase as titanium tetrachloride by chlorinating said unreacted titanium-containing material in said chlorination zone.