METHOD FOR PRODUCING TANTALUM POWDER, TANTALUM POWDER AND TANTALUM ELECTROLYTIC CAPACITOR

摘要

A method for producing a tantalum powder, which comprises a high temperature heat treatment step of reducing tantalum potassium fluoride with sodium and subjecting the resultant reduced tantalum powder to a high temperature heat treatment in an inert atmosphere, a low temperature heat treatment step of pulverizing tantalum coagulants from the high temperature heat treatment step, adding magnesium to the resultant powder and subjecting the mixture to a low temperature heat treatment under a reduced pressure, and an acid washing step of washing the product with an acidic solution, wherein the high temperature heat treatment step is carried out at a temperature of 1000 ° or higher and lower than 1250 °, and the low temperature heat treatment step is carried out at a temperature of 700 ° to 1000 °. The method can be employed for producing a tantalum powder having a CV of 80,000 to 250,000 µFV/g, and further allows the production of a tantalum powder having a CV higher than 80,000 to 250,000 νFV/g.