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 method for producing a metal ingot by using an electron-beam melting furnace having an electron gun and a hearth that accumulates a molten metal of a metal raw material, wherein the metal raw material is supplied to the position on a supply line disposed along a second side wall of the hearth that accumulates the molten metal of the metal raw material. A first electron beam is radiated along a first irradiation line that is disposed along the supply line and is closer to a central part of the hearth relative to the supply line on the surface of the molten metal, wherein a surface temperature (T2) of the molten metal at the first irradiation line is made higher than an average surface temperature (T0) of the entire surface of the molten metal in the hearth.

A method for producing a metal ingot by using an electron-beam melting furnace having an electron gun and a hearth that accumulates a molten metal of a metal raw material, wherein the metal raw material is supplied to the position on a supply line disposed along a second side wall of the hearth that accumulates the molten metal of the metal raw material. A first electron beam is radiated along a first irradiation line that is disposed along the supply line and is closer to a central part of the hearth relative to the supply line on the surface of the molten metal, wherein a surface temperature (T2) of the molten metal at the first irradiation line is made higher than an average surface temperature (T0) of the entire surface of the molten metal in the hearth.

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.

An apparatus for melting metals whose melting temperature is below 1000° C. may have a device for forming a plasma arranged on a melting furnace. The device is connected to an electrical voltage supply and to the device at least one first supply for a plasma gas, with which the plasma can be formed, and is designed, dimensioned, arranged and/or aligned in such a way that the formed plasma is arranged at a distance from the metal as the material to be melted, and in this case a hot gas stream can be formed with the plasma, which hot gas stream is aligned in the direction of the material to be melted, and a melting tank or crucible is arranged in the melting furnace to receive the molten metal.

Provided are a method and apparatus for refining titanium scraps and sponge titanium, which can remove oxygen from a melt by supplying a deoxidizing gas to the surface of the melt in order to refine titanium scraps and sponge titanium. The method for refining titanium scraps and sponge titanium comprises supplying hydrogen ions and electrons in plasma to a titanium melt to remove oxygen from the titanium melt surface having an oxide layer formed thereon. In addition, the apparatus comprises: a vacuum chamber; a crucible located in the vacuum chamber and configured to perform melting by the magnetic field of an induction coil in a state in which a melt and the inner wall of the crucible; a calcium gas supply means configured to supply calcium gas from the bottom of the crucible to the space between the inner wall of the crucible and the melt.

High quality titanium ingot is produced by using recovered titanium scrap as a raw material and adding additives. Scrap, each having individual information of identification and process profile information, is passed through automatic reading means to obtain the information and to store it in a data server. A calculating means calculates a combination of the scrap, titanium sponge and additives and feed rate of each of them so as to satisfy chemical composition and producing rate of a target ingot product using the individual identification pieces of information stored in the data server, during a beginning step of the ingot production, and transmits electrical signals corresponding to calculated results of the combination and the feed rates from the calculating means to a feed rate controlling means of each feed means of the titanium scrap, titanium sponge, and additives and then starting supply of them, and detecting means equipped at an extracting part of the ingot product reads actual producing rate of the ingot product, after the beginning step of the ingot production. The calculating means controls feed rate of the titanium scrap, titanium sponge, and/or additives based on the actual producing rate.

The invention concerns a process for the separation of cobalt from lithium present in a charge comprising lithium-ion batteries or related products, comprising the steps of: smelting the charge using a bath furnace equipped with a submerged air-fed plasma torch for injecting plasma gas into the melt; defining and maintaining a bath redox potential where cobalt is reduced to the metallic state and reporting to an alloy phase, and whereby lithium is oxidized as Li.sub.2O and reporting to the slag phase; decanting and separating the phases. It is characterized in that the reduction and oxidizing steps are performed simultaneously. A suitably low cobalt concentration is obtained in the slag.

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, Jr, 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.

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, Jr, 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.