PRODUCTION OF HIGH-PURITY NIOBIUM OXIDE OR TANTALUM OXIDE

摘要

PURPOSE:To readily obtain the title oxide at low cost by extracting a solution containing niobium or tantalum using a specific extraction solvent followed by washing the resultant extraction solvent phase with a specific cleaning agent. CONSTITUTION:A solution containing niobium or tantalum is extracted with, as an extraction solvent, trioctylphosphine oxide plus a petroleum-based hydrocarbon diluent followed by washing the resultant extraction solvent phase using, as a cleaning agent, a solution prepared by mixing ammonium fluoride with a mineral acid to adjust the pH to 3-5. The concentration of the trioctylphosphine oxide in said extraction solvent should normally be 20-40v/v%. Said petroleum-based hydrocarbon diluent is e.g., toluene, xylene, benzene, kerosene.