Method for the production of valve metal powders

A process for the deoxidation of valve metal powders which comprises reducing a metal and/or its hydride under an inert carrier gas, wherein the deoxidation is carried without contact between the valve metal powder to be deoxidized and liquid reducing metal and/or metal hydride.

A process for the production of tantalum powder for electrolytic capacitors which comprises subjecting a tantalum primary powder with a specific surface of 4 to 20 m2/g to a deoxidation with magnesium vapor at a magnesium vapor pressure of 5 to 110 hPa without contact with liquid magnesium.

A tantalum powder with a specific surface of 4 to 8 m2/g, which after pressing at a pressing density of 5 g/cm3 and sintering at 1210° C. over 10 minutes has, after forming up to a forming voltage of 10V, a capacity of 220,000 to 350,000 μFV/g.

A tantalum powder with a specific surface of 3.5 to 6 m2/g, which after pressing at a pressing density of 5 g/cm3 and sintering at 1210° C. over 10 minutes has, after forming up to a forming voltage of 10V, a capacity of 180,000 to 250,000 μFV/g.