Process for Purifying a Titanium-Bearing Material and Upgrading Ilmenite to Synthetic Rutile With Sulfur Trioxide.
Elger-GW; Stadler-RA; Sanker-PE
U S Pat 4 120 694 1978 Oct; :
A process for removing impurities from an oxide of titanium-bearing material such as a titania slag by treating the material with so3 gas and subsequently leaching with a liquid. In particular a process for upgrading an ilmenite ore by preparing a titania slag therefrom and purifying the slag such that it may be used as a synthetic rutile suitable for use in a fluidized-bed chlorination reactor to produce titanium tetrachloride that can be reoxidized to tio2. Thus, 5 g of a titania slag with a composition feo 5.3, Tio2 70.6, Sio2 6.8, Mgo 4.1, Cao 8.2, Al2o3 4.5 and other (including v and cr) 0.5, Was treated with so3 and o2 at 900 deg c and cooled under a so3 atmosphere. The slag contained pseudobrookite material as a primary phase and calcium titanate as a minor phase. The so3 was made by passing so2 and o2 over a v2o5 catalyst bed heated to 400 deg c. After treatment with so3, the slag was found to have a sulfur content of 5.6 Wt pct. After cooling to room temperature the sample was allowed to sit in water at room temperature and then dried. About 60 wt pct of the mgo and 40 wt pct of the cao in the original slag were removed by the water leach step.
U.S. Pat. 4,120,694, Oct. 17, 1978; Chem. Abstr. Not Found