Manufacture of Synthetic Rutile.
Stickney-WA; Hunter-WL; Elger-GW; Rhoads-SC
U S Pat 3 739 061 1973 Jun; :
Rutile is manufactured and recovered from a reduced titaniferous slag, by oxidation at >650 deg. C to convert at least a major portion of the ti compounds in the slag to microcrystalline rutile. Then the oxidized slag is heated to >1,200 deg. C in the presence of a substance, e.g., phosphorus oxides or compounds which decompose to phosphorus oxides, in an amount >1 part of the substance to 20 parts of slag by weight to form enlarged rutile crystals dispersed within a friable glassy matrix material. The rutile-containing matrix material is then comminuted to a size range where rutile crystals can be substantially freed from the glassy matrix by specific gravity differences. The process can be used when the reduced titaniferous slag is derived from the smelting of ilmenite and has a residual fe content of <5 pct.
U.S. Pat. 3,739,061; June 12, 1973; Chem. Abstr. 79:94,139H