E. I. du Pont de Nemours patents ilmenite ore process

August 15, 2012

U.S. 8,137,647 B2
E. I. du Pont de Nemours and Company has obtained a patent for a process comprised of digesting ilmenite ore with aqueous ammonium hydrogen oxalate to form a leachate and a precipitate comprised of FeC2O4.2H2O; separating the leachate from the precipitate comprised of FeC2O4.2H2O; hydrolyzing the leachate with ammonia or ammonium hydroxide to form titanyl hydroxide and an oxalate-rich solution; separating the titanyl hydroxide from the oxalate-rich solution; washing the titanyl hydroxide with a material selected from the group consisting of water, aqueous ammonium oxalate and ammonium hydroxide to form low oxalate titanyl hydroxide, that is, titanyl hydroxide that is stripped of residual oxalate; and crystallizing titanium dioxide from the low oxalate titanyl hydroxide.