It is preferable that metallic sodium to be loaded to an engine valve used for an internal combustion engine such as automobile engine have high purity. However, conventionally, an organic solvent remaining in micropores on a surface of the metallic sodium have been hardly attracted attention. Provided is a method for purifying metallic sodium including steps of placing metallic sodium containing organic solvent in the micropores thereof in a melting tank which is sealed, and heating the melting tank under reduced pressure to vaporize and remove the organic solvent coating the metallic sodium.

A method produces tantalum powder by reducing tantalum oxide with an alkaline earth metal. The method includes (1) mixing tantalum oxide with an excessive alkaline earth metal reducing agent, simultaneously mixing at least one alkali metal and/or alkaline earth metal halide accounting for 10-200% of the weight of the tantalum oxide, heating the mixture to a temperature of 700-1200? C. in a furnace filled with inert gas, and soaking so that the tantalum oxide and reducing agent are subjected to a reduction reaction; (2) at the end of soaking, lowering the temperature to 600-800? C., vacuumizing the interior of the furnace to 10 Pa or less, and soaking under the negative pressure so that the excessive magnesium and tantalum powder mixture are separated; (3) thereafter, raising the temperature of the furnace to 750-1200? C. in the presence of inert gas, and soaking so that the tantalum powder is further sintered in the molten salt; (4) then cooling to room temperature and passivating to obtain a mixed material containing halide and tantalum powder; and (5) separating the tantalum powder from the mixture.

The present invention discloses a method for producing high-purity magnesium by semi-continuous distillation, comprising the following steps of: (1) melting crude magnesium or recycled mixed metal containing magnesium containing various impurities in a melting boiler; (2) feeding the molten crude magnesium into a second boiler by a magnesium liquid delivery pump, and maintaining a temperature of 665 C. to 700 C.; (3) sucking the high-temperature magnesium liquid into a crude distillation column in vacuum by a magnetic liquid suction pipe that is inserted into the intermediate boiler and connected to the crude distillation column. Magnesium is condensed into liquid in the rectification column, then discharged from a liquid seal of the rectification column, and ingoted in a refined magnesium die to obtain high-purity magnesium products.

A subject for the invention is to diminish the occurrence of streak-type segregation in producing a material comprising a Ni-based superalloy. The invention relates to a Ni-based superalloy having excellent unsusceptibility to segregation, characterized by comprising: 0.005 to 0.15 mass % of C; 8 to 22 mass % of Cr; 5 to 30 mass % of Co; equal or greater than 1 and less than 9 mass % of Mo; 5 to 21 mass % of W; 0.1 to 2.0 mass % of Al; 0.3 to 2.5 mass % of Ti; up to 0.015 mass % of B; and up to 0.01 mass % of Mg, with the remainder comprising Ni and unavoidable impurities.

A method and an equipment for the treatment of molten aluminium metal, in particular Na removal in a tapping/transport crucible (1) provided with a lid (6). The atmosphere above the molten metal is sub-pressurized to a sub pressure between 300-10 mbar and subsequently exposed to a stirring action generated by an electromagnetic coil (EMS) arranged towards one side of the tapping/transport crucible (1), whereby Na can be removed from the molten aluminium metal without any addition of active or passive agents.

The invention relates to a method for re-melting coated aluminum alloy scrap comprising a step of supplying shredded coated aluminum alloy scrap, consisting of individual entities; a decoating step, a step of preparing a heel, a step of loading and melting the decoated scrap on the heel. The invention is characterized in that the scrap has a specific geometry wherein at least 50% of the individual entities of the shredded coated scrap has a fold ratio (R) of less than or equal to 0.6, wherein the fold ratio (R) of an individual entity is defined by: fold ratio=R=(unfolded areafolded area)/(unfolded area), wherein the folded area is the maximum area of the orthogonal projection of the individual entity onto a plane and the unfolded area is the total area of the same individual entity after it has been unfolded.

It is preferable that metallic sodium to be loaded to an engine valve used for an internal combustion engine such as automobile engine have high purity. However, conventionally, an organic solvent remaining in micropores on a surface of the metallic sodium have been hardly attracted attention. Provided is a method for purifying metallic sodium including steps of placing metallic sodium containing organic solvent in the micropores thereof in a melting tank which is sealed, and heating the melting tank under reduced pressure to vaporize and remove the organic solvent coating the metallic sodium.

A furnace has a melting chamber with a periphery defined by a surrounding wall structure. The furnace is provided with a purge system configured to direct inert gas to flow downward in the melting chamber in the configuration of a curtain that adjoins the wall structure and reaches only partially around the periphery of the melting chamber.

According to one aspect of the invention, a system to separate salt from uranium. The system has a vessel, a heater, a pump, and a condenser. The vessel is adapted to receive a uranium that has a salt concentration. The heater heats the uranium for a period of time, causing the salt to turn into a salt vapor and the uranium to melt. The melted uranium releases the salt vapor. The pump circulates an inert gas that carries the salt vapor away from the melted uranium. The condenser is adapted to receive the salt vapor.

A subject for the invention is to diminish the occurrence of streak-type segregation in producing a material comprising a Ni-based superalloy. The invention relates to a Ni-based superalloy having excellent unsusceptibility to segregation, characterized by comprising: 0.005 to 0.15 mass % of C; 8 to 22 mass % of Cr; 5 to 30 mass % of Co; equal or greater than 1 and less than 9 mass % of Mo; 5 to 21 mass % of W; 0.1 to 2.0 mass % of Al; 0.3 to 2.5 mass % of Ti; up to 0.015 mass % of B; and up to 0.01 mass % of Mg, with the remainder comprising Ni and unavoidable impurities.