Synthesis of Rutile from Titaniferous Slags.
U S Pat 3 996 332 1976 Dec; :
Ilmenite is mixed with carbon and lime and smelted to form molten iron and a slag containing 3-5 pct feo. The molten slag is removed and treated at 1,400 deg-1,700 deg c with o2 for 10-60 s to remove c and convert feo to fe2o3 and mixed with titanium pyrophosphate to convert non-ti components of the slag to a friable phosphate glass. The treated molten slag is aged 0.5-20 H to permit growth of tio2 crystals to 100-150 um and then cooled and crushed or granulated by water quenching, attrition scrubbed, and extracted with 4-8 pct h2so4 to dissolve the phosphate glass and leave a residue of tio2 crystals.
U.S. Pat. 3,996,332; Dec. 7, 1976; Chem. Abstr. 85:P162,722u