原料物質および還元剤の外部連続供給法によるタンタル粉末の製造

Abstract

In order to produce high-quality tantalum powder of spherical shape with a uniform particle size and a high purity using metalothermic reduction process, it is important to control the reaction temperature and reaction rate.In this study, we developed a metallothermic reduction method using the system supplying materials continuously from the external unit where the feed material of K2TaF7 and Na as a reductant were continuously supplied into the reaction furnace and the reaction rate was controlled.The characteristics of tantalum powder produced by the continuous supply system were compared with those of the powder produced by a batch system that the whole amount of the feed material and reductant were supplied all together into the reaction furnace at one time.We could get tantalum powder with spherical shape and uniform particlesize with the diameter of 2∼3 μm because we used the external continuous supply system where the reaction temperature and reaction rate could be well controlled.After deoxidation, dehydration, and heat treatments, the purity of the tantalum power reached to 99.5 mass% level of the reagent grade. The yield of tantalum powder increased from 80% in the batch system to 90% in the external continuous supply system