METHOD OF PROCESSING OF LOPARITE CONCENTRATE Russian patent published in 2002 - IPC

FIELD: less-common metal technology. SUBSTANCE: loparite concentrate is decomposed by 69-71% nitric acid at 100-110 C for 38-42 h. Hydrate precipitate of titanium, niobium, and tantalum is separated and treated with hydrogen fluoride-containing reagent (hydrofluoric acid or hydrogen fluoride-water steam mixture) at weight ratio of reagent to dry hydrate precipitate (0.9-1.0):1 (on conversion to 100% HF). Then. Niobium and tantalum are separated from titanium using extraction technique with aliphatic alcohols, wherein niobium and tantalum are transferred into organic phase, whereas titanium remains in aqueous phase. Aliphatic alcohols utilized are those from C7-C9 alcohol fraction, preferably 1-octanol, 2-octanol, or their mixture. Into aqueous phase, zinc metal in amount of no more than 5% counting on the weight of titanium dioxide is added and resulting mixture is subjected to heat treatment at 500-750 C to form titanium dioxide. The latter is treated with a modifier to give pigmentary rutile. Modifier is aluminum phosphate/silicic acid mixture and its amount corresponds to consumption of 1-10% aluminum oxide and 1-10% silicon oxide based on titanium dioxide. Consumption of hydrogen fluoride-containing reagent is reduced by 1.2 times. EFFECT: improved quality of titanium dioxide. 4 cl, 1 tbl, 5 ex