METHOD OF PRODUCTION OF OXIDES OF REFRACTORY METALS FROM LOPARITE CONCENTRATE Russian patent published in 2000 - IPC

FIELD: production of oxides of refractory metals from loparite concentrate. SUBSTANCE: proposed method includes grinding of concentrate and break-down with concentrated nitric acid at atmospheric pressure and temperature above 100 C, thus obtaining pulp of hydrate cake of refractory metal oxides followed by fluorination for obtaining fluoride solution of tantalum, niobium and titanium. Extraction from solution is effected by means of actyl alcohol followed by water reextraction of fluotantal and fluoniobium acids and concentration of remaining fluotitanic acid by evaporation. Extraction of tantalum and niobium oxides from fluotantal and fluoniobium acids and titanium dioxide from fluotitanic acid is performed by high-temperature pyrolysis at temperature of from 600 to 650 C. Fluorination of hydrate cake pulp is performed through absorption of gaseous hydrogen fluoride from flue gases by pump; flue gases are formed due to high-temperature pyrolysis of fluotantal, fluoniobium and fluotitanic acids; to this end, flue gases and hydrate cake pulp are directed in counterflow in pulp recirculation mode. EFFECT: simplification of method; enhanced operational and economical efficiency. 1 tbl, 1 ex