Abstract: A method for passivating tantalum metal surface is provided, the method comprises cooling tantalum metal to or below 32° C. and/or passivating tantalum metal surface by oxygen-containing gas with a temperature of 0° C. or below. Also provided is an apparatus for passivating tantalum metal surface for applying the method, comprising a heat treatment furnace, an argon forced-cooling device and/or a device for cooling oxygen-containing gas.

Abstract: A method for spherically granulating and agglomerating metal particles such as tantalum and/or niobium powders is described in the present invention, which includes the steps of: a). comminuting the metal particles to form fine particles having D50 less than 50 ?m; b). granulating the comminuted metal particles comprising volatile liquid, for example, tantalum and/or niobium particles comprising volatile liquid, to form wet spherical particles; c). still drying the wet spherical particles and removing volatile liquid to form flowable pre-agglomerated particles with increased bulk density; d). heat treating the pre-agglomerated particles; e). screening the heat treated powder to obtain the flowable agglomerated particles. The present invention provides a flowable spherical agglomerated metal particles, and especially tantalum and/or niobium particles having improved properties. The present agglomerated tantalum powder have a flow rate of at least about 2.0 g/sec, a BET surface area of from about 0.

Abstract: A method for spherically granulating and agglomerating metal particles such as tantalum and/or niobium powders is described in the present invention, which includes the steps of: a). comminuting the metal particles to form fine particles having D50 less than 50 ?m; b). granulating the comminuted metal particles comprising volatile liquid, for example, tantalum and/or niobium particles comprising volatile liquid, to form wet spherical particles; c). still drying the wet spherical particles and removing volatile liquid to form flowable pre-agglomerated particles with increased bulk density; d). heat treating the pre-agglomerated particles; e). screening the heat treated powder to obtain the flowable agglomerated particles. The present invention provides a flowable spherical agglomerated metal particles, and especially tantalum and/or niobium particles having improved properties. The present agglomerated tantalum powder have a flow rate of at least about 2.0 g/sec, a BET surface area of from about 0.

Abstract: A method for spherically granulating and agglomerating metal particles such as tantalum and/or niobium powders is described in the present invention, which includes the steps of: a). comminuting the metal particles to form fine particles having D50 less than 50 ?m; b). granulating the comminuted metal particles comprising volatile liquid, for example, tantalum and/or niobium particles comprising volatile liquid, to form wet spherical particles; c). still drying the wet spherical particles and removing volatile liquid to form flowable pre-agglomerated particles with increased bulk density; d). heat treating the pre-agglomerated particles; e). screening the heat treated powder to obtain the flowable agglomerated particles. The present invention provides a flowable spherical agglomerated metal particles, and especially tantalum and/or niobium particles having improved properties. The present agglomerated tantalum powder have a flow rate of at least about 2.0 g/sec, a BET surface area of from about 0.