While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dx.sub.(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

There are provided high melting point metal or alloy powder atomization manufacturing processes comprising providing a melt of the high melting point metal or alloy through a feed tube; diverting the melt at a diverting angle with respect to a central axis of the feed tube to obtain a diverted melt; directing the diverted melt to an atomization area; and providing at least one atomization gas stream to the atomization area. The atomization process can be carried out in the presence of water within an atomization chamber used for the atomization process.

Metallurgical processes and systems for gas atomization of molten slag and/or molten metals from a metallurgical furnace are integrated with off-gas handling processes and equipment, such that the off-gases are fed to the gas atomization plant for atomizing the molten slag and/or molten metal. The use of by-product off-gases for atomizing molten slag and/or molten metals provides a number of benefits, including elimination of off-gas handling and treatment equipment, centralization and upgrading of heat via atomization to improve heat recovery, prevention of oxidation of granular products of atomization, and reduction of CO.sub.2 emissions. A process for preparing a granular product comprises: feeding a molten material and a by-product off-gas to a dispersion apparatus; and contacting the gas with the molten material in the dispersion apparatus, whereby the molten material is dispersed and solidified by contact with the gas to form the granular product.

There are provided high melting point metal or alloy powder atomization manufacturing processes comprising providing a melt of the high melting point metal or alloy through a feed tube; diverting the melt at a diverting angle with respect to a central axis of the feed tube to obtain a diverted melt; directing the diverted melt to an atomization area; and providing at least one atomization gas stream to the atomization area. The atomization process can be carried out in the presence of water within an atomization chamber used for the atomization process.

An apparatus for producing metallic powders from molten feedstock includes a heating source for melting a solid feedstock into a molten feed, and a crucible for containing the molten feed. A liquid feed tube is also provided to feed the molten feed as a molten stream. A plasma source delivers a plasma stream, with the plasma stream being adapted to be accelerated to a supersonic N velocity and being adapted : to then impact the molten stream for producing metallic powders. The feed tube extends from the crucible to a location where a supersonic plasma plume atomizes the molten stream. The plasma source includes at least two plasma torches provided with at least one supersonic nozzle aimed towards the molten stream. The multiple plasma torches are disposed symmetrically about the location where the supersonic plasma plumes atomize the molten stream, such as in a ring-shaped configuration.

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dx.sub.(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

Disclosed here is a method for making a nanoporous material, comprising aerosolizing a solution comprising at least one metal salt and at least one solvent to obtain an aerosol, freezing the aerosol to obtain a frozen aerosol, and drying the frozen aerosol to obtain a nanoporous metal compound material. Further, the nanoporous metal compound material can be reduced to obtain a nanoporous metal material.

A method for producing material powder, comprising providing material and an atomization gas charged with an atomization gas pressure by means of an atomization gas compressor to an atomization device, melting the material and pulverizing the molten material into material powder by means of charging the molten material with the atomization gas using the atomization introducing the material powder from the atomization device into a pressurized container and providing a conveyor gas charged with a conveyer gas pressure by means of a conveyer gas compressor to the pressurized container, wherein the conveyor gas pressure is higher than the atmospheric pressure and lower than the atomization gas pressure, as well as a device for carrying out the method.

There are provided high melting point metal or alloy powder atomization manufacturing processes comprising providing a melt of the high melting point metal or alloy through a feed tube; diverting the melt at a diverting angle with respect to a central axis of the feed tube to obtain a diverted melt; directing the diverted melt to an atomization area; and providing at least one atomization gas stream to the atomization area. The atomization process can be carried out in the presence of water within an atomization chamber used for the atomization process.

A gas supply device for a manufacturing device includes an inert gas supply source that supplies inert gas, a supply line connected to the inert gas supply source, a nitrogen removal portion that is provided on the supply line and that removes at least a portion of nitrogen in the inert gas, and an oxygen removal portion that is provided on the supply line and that removes at least a portion of oxygen in the inert gas.