A method for the production of metal powders or metal hydride powders of the elements Ti, Zr, Hf, V, Nb, Ta, and Cr is disclosed, whereby an oxide of the said elements is mixed with a reducing agent and said mixture, optionally with a hydrogen atmosphere (for the production fo metal hydrides), is heated until the reduction reaction commences, the reaction product is quenched, then washed and dried. The oxide used has an average particle size of 0.5 to 20 m, a BET specific surface of 0.5 to 20 m.sup.2/g and a minimum content of 94 wt %.

A method for the production of metal powders or metal hydride powders of the elements Ti, Zr, Hf, V, Nb, Ta, and Cr is disclosed, whereby an oxide of the said elements is mixed with a reducing agent and said mixture, optionally with a hydrogen atmosphere (for the production fo metal hydrides), is heated until the reduction reaction commences, the reaction product is quenched, then washed and dried. The oxide used has an average particle size of 0.5 to 20 m, a BET specific surface of 0.5 to 20 m.sup.2/g and a minimum content of 94 wt %.

A method for separating an amount of osmium from a mixture containing the osmium and at least one other additional metal is provided. In particular, method for forming and trapping OsO.sub.4 to separate the osmium from a mixture containing the osmium and at least one other additional metal is provided.

A method for separating an amount of osmium from a mixture containing the osmium and at least one other additional metal is provided. In particular, method for forming and trapping OsO.sub.4 to separate the osmium from a mixture containing the osmium and at least one other additional metal is provided.

A niobium or niobium alloy which contains pure or substantially pure niobium 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 niobium alloy that is resistant to aqueous corrosion. The invention also relates to the process of preparing the niobium alloy.

There are provided processes for treating red mud. For example, the processes can comprise leaching red mud with HCl so as to obtain a leachate comprising ions of a first metal (for example aluminum) and a solid, and separating said solid from said leachate. Several other metals can be extracted from the leachate (Fe, Ni, Co, Mg, rare earth elements, rare metals, etc.). Various other components can be extracted from solid such as TiO.sub.2, SiO.sub.2 etc.

A method includes forming a solution comprising a solvent and at least two elements selected from: scandium (Sc), yttrium (Y), one or more lanthanides, and one or more actinides. The method includes adding an effective amount of at least one polyoxometalate for forming complexes with at least one of the elements and adding an effective amount of a cation for causing precipitation of at least some of the complexes of one of the elements. Substantially all of another of the elements remains in solution during the precipitation of the at least some of the complexes of the one of the elements. A kit includes a polyoxometalate, a cation, and instructions for adding effective amounts of the polyoxometalate and the cation for separating at least two elements selected from the group consisting of: scandium (Sc), yttrium (Y), one or more lanthanides, and one or more actinides via a precipitation reaction.

A method includes forming a solution comprising a solvent and at least two elements selected from: scandium (Sc), yttrium (Y), one or more lanthanides, and one or more actinides. The method includes adding an effective amount of at least one polyoxometalate for forming complexes with at least one of the elements and adding an effective amount of a cation for causing precipitation of at least some of the complexes of one of the elements. Substantially all of another of the elements remains in solution during the precipitation of the at least some of the complexes of the one of the elements. A kit includes a polyoxometalate, a cation, and instructions for adding effective amounts of the polyoxometalate and the cation for separating at least two elements selected from the group consisting of: scandium (Sc), yttrium (Y), one or more lanthanides, and one or more actinides via a precipitation reaction.

A process is provided for recovering a refractory metal. A comminuted precursor material includes the refractory metal to be recovered in oxidically bound form. A reactant of loose solids includes a slag former having a higher O.sub.2 affinity than the refractory metal. A heat-resistant reaction vessel is filled with a charge of a mixture of the precursor material and the reactant. The process triggers an exothermic redox reaction of the charge, while an inertia force acts on the reaction vessel. The charge is melted, whereby the molten refractory metal and the slag are separated owing to the inertia force that acts on the vessel during the exothermic redox reaction. The reaction vessel with at least the reaction products is cooled. Reaction products are removed from the reaction vessel, and the refractory metal is separated from the slag.

A process is provided for recovering a refractory metal. A comminuted precursor material includes the refractory metal to be recovered in oxidically bound form. A reactant of loose solids includes a slag former having a higher O.sub.2 affinity than the refractory metal. A heat-resistant reaction vessel is filled with a charge of a mixture of the precursor material and the reactant. The process triggers an exothermic redox reaction of the charge, while an inertia force acts on the reaction vessel. The charge is melted, whereby the molten refractory metal and the slag are separated owing to the inertia force that acts on the vessel during the exothermic redox reaction. The reaction vessel with at least the reaction products is cooled. Reaction products are removed from the reaction vessel, and the refractory metal is separated from the slag.