A method of producing metallic tantalum comprises the steps of providing a precursor comprising a tantalate of a first metal, arranging the precursor material in contact with a molten salt in an electrolytic cell, the electrolysis cell further comprising an anode and a cathode arranged in contact with the molten salt, and applying a potential between the anode and the cathode such that the precursor material is reduced to tantalum. The first metal is an alkali metal or an alkaline earth metal. The anode does not comprise a carbon material, which prevents contamination of the tantalum and improves current efficiency of the process.

A method of producing metallic tantalum comprises the steps of providing a precursor comprising a tantalate of a first metal, arranging the precursor material in contact with a molten salt in an electrolytic cell, the electrolysis cell further comprising an anode and a cathode arranged in contact with the molten salt, and applying a potential between the anode and the cathode such that the precursor material is reduced to tantalum. The first metal is an alkali metal or an alkaline earth metal. The anode does not comprise a carbon material, which prevents contamination of the tantalum and improves current efficiency of the process.

The invention relates to a method for cutting refractory metals, in which a solid body (1) made of a refractory metal is mechanically machining cut with a cutting apparatus (4, 7), wherein the cutting apparatus (4, 7) is wetted for cutting with a fluid (6) having at least 50 weight % water, wherein the cutting apparatus (4, 7) is brought to a positive electrical potential in relation to the solid body (1) during cutting. The invention also relates to a disc produced from a refractory metal using such a method, and such a disc that has an oxide layer with a thickness of between 2 nm and 1,000 nm on the cutting surface.

Refined niobium-based ferroalloys are provided by removing lead and other impurities therefrom by a process comprising charging niobium ore concentrate and/or niobium oxide or a mixture of niobium oxides to a metallothermic reaction chamber, admixing the ore concentrate and/or niobium oxide with a reducing agent, initiating a metallothermic reaction, under reduced pressure; and allowing the reaction product to solidify and cool; crushing the reaction product or crushing the niobium-based ferroalloy previously reduced in open air, and charging the crushed product to a melting crucible within a vacuum induction melting furnace, lowering the pressure within the furnace to below 1 mbar, and melting the crushed product while vaporizing the impurities contained therein.

Refined niobium-based ferroalloys are provided by removing lead and other impurities therefrom by a process comprising charging niobium ore concentrate and/or niobium oxide or a mixture of niobium oxides to a metallothermic reaction chamber, admixing the ore concentrate and/or niobium oxide with a reducing agent, initiating a metallothermic reaction, under reduced pressure; and allowing the reaction product to solidify and cool; crushing the reaction product or crushing the niobium-based ferroalloy previously reduced in open air, and charging the crushed product to a melting crucible within a vacuum induction melting furnace, lowering the pressure within the furnace to below 1 mbar, and melting the crushed product while vaporizing the impurities contained therein.

A tantalum or tantalum alloy which contains pure or substantially pure tantalum and at least one metal element selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Mo, W and Re to form a tantalum alloy that is resistant to aqueous corrosion. The invention also relates to the process of preparing the tantalum alloy.

In various embodiments, a metal alloy resistant to aqueous corrosion consists essentially of or consists of niobium with additions of tungsten, molybdenum, and one or both of ruthenium and palladium.

In various embodiments, a metal alloy resistant to aqueous corrosion consists essentially of or consists of niobium with additions of tungsten, molybdenum, and one or both of ruthenium and palladium.

A process for recovering metal value-containing precipitates in consistently high concentrations from a metal-containing composition by combining selective roasting and leaching steps.

A process for recovering metal value-containing precipitates in consistently high concentrations from a metal-containing composition by combining selective roasting and leaching steps.