Extraction of Ta and Nb from a Coltan Bearing Ore by Means of Ammonium Bifluoride Fluorination and Sulfuric Acid Leaching

A novel approach for Ta and Nb extraction consisting of the pre-treatment a coltan-bearing ore with an ammonium bifluoride sub-molten salt subsequent acid leaching has been studied. The effects from granulometry, (ABF) to mass ratio, temperature duration fluorination on degree were examined. ABF ratio process found have most pronounced impact efficiency. following optimal conditions determined: granulometric fraction (−75 + 45 µm), ABF-ore (5/1), (200 °C) time (2.5 h). Maintaining these parameters enabled about 94% 95% be brought into solution during sulfuric-acid-leaching stage. comparison proposed method previously reported studies suggests that due mechanical agitation recirculation HF-containing gaseous phase back process, dosage rate at stage could reduced significantly without sacrificing overall recovery Nb. In such way, offer added environmental benefits since release fluoride-containing effluents environment limited.