Process for the preparation of tantalum and niobium powders of improved efficiency

摘要

An anhydrous mixture of extrudable viscosity of an activated alkali metal tantalum or niobium halide powder, an alkali metal halide powder, and a molten alkali metal in about 1:0.75-2.0:4.75-5.5 molar ratio is formed into a paste which is extruded and formed into masses of critical dimensions and temperature. The mass is ignited and a self-sustaining reduction reaction ensues. The reaction product is powdered, washed and dried. The product is pure tantalum or niobium powder in almost quantitative yield. The powder is specially suited for use as electrolytic capacitor anodes. The powder is improved by passage through a plasma of an inert gas. The process can be performed on a continuous scale.