Soda Ash Smelting of Ilmenite.
Gomes-JM; O'Keefe-DA; Wong-MM
105th AIME Ann Mtg Las Vegas Nevada, 1976 Feb;(A76-27):557-558
The federal Bureau of Mines developed a smelting-leaching procedure for preparing sodium titanate from domestic ilmenite. This sodium titanate product, containing 70 to 80 wt-pct tio2, 15 to 20 wt-pct na2o, and less than 1 wt-pct iron, can be used as a feed material in place of ilmenite for preparing titania pigment by the sulfate process. Substitution of titanate for ilmenite minimizes the formation of ferrous sulfate waste that results during operation of the process. Under optimum conditions, 1 part rock ilmenite or alluvial ilmenite is smelted with 0.25 Part soda ash and 0.1 Part coke at 1,250 deg c to yield pig iron and a titanate slag. Over 99 pct of the tio2 is recovered in the slag, and about 95 pct of iron is recovered in the pig iron. The molten slag is quenched and leached in water to remove soluble soda and upgrade the tio2 content. The titanate product is then digested in 50 to 96 wt-pct sulfuric acid to solubilize over 90 pct of the tio2. Pigment-grade tio2 is produced by hydrolysis of the titanium sulfate solution followed by calcining the hydrous titanium oxide precipitate.
105th AIME Ann. Mtg., Las Vegas, Nevada, Feb. 22-26, 1976, Paper No. A76-27, PP. 557-558