An investigation on hydrofluoric (HF) acid-free extraction for niobium oxide (Nb2O5) and tantalum oxide (Ta2O5) from columbite/tantalite concentrates using alkali reductive roasting

Tantalum, niobium, and their oxides are important precursor materials, essential for high-temperature alloys electronic devices. The primary hydrometallurgical extraction technique to extract tantalum niobium from minerals involves hydrofluoric acid (HF) digestion of the concentrates, followed by solvent as an oxide separation purification step. Solvent extraction, on other hand, releases organic solvents which lost irreversibly via natural evaporation during process. This research demonstrates a novel chemical process refining columbite tantalite concentrates (29% Ta2O5 16% Nb2O5). In this process, reduced using carbon alkali in temperature range 800–950 °C, helps reducing magnetically separating iron present metallic iron. remaining residue is rich complex (e.g., sodium tantalates niobates) formed roasting was reclaimed purified mixture Nb2O5 Ta2O5, oxalic leaching, bisulphate roasting.