A method and system for recovering a high yield of low carbon ferrochrome from chromite and low carbon ferrochrome produced by the method. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers. The feed materials are heated, whereupon the aluminum in the aluminum granules produces an exothermic reaction reducing the chromium oxide and iron oxide in the chromite to produce molten low carbon ferrochrome with molten slag floating thereon. The molten low carbon ferrochrome is extracted, solidified and granulated into granules of low carbon ferrochrome. The molten slag is extracted, solidified and granulated into granules of slag.

A lead-based alloy containing alloying additions of bismuth, antimony, arsenic, and tin is used for the production of doped leady oxides, lead-acid battery active materials, lead-acid battery electrodes, and lead-acid batteries.

A metal powder production apparatus includes a molten metal supply section which supplies a molten metal, a cylindrical body which includes an upper part placed on a lower side of the molten metal supply section and a lower part provided on a lower side of the upper part, a fluid jet section which jets a gas (fluid) toward the molten metal, and a cooling liquid outflow section which allows a cooling liquid to flow out along the inner circumferential surface of the upper part. In the metal powder production apparatus, an angle formed by the axial line of the upper part of the cylindrical body and the vertical line is 0 or more and 20 or less, and an angle formed by the axial line of the lower part of the cylindrical body and the vertical line is 0 or more and 20 or less.

A process for manufacturing metal powders including (i) discharging metal particles from a chamber of a gas atomizer in a conveyor, (ii) simultaneously cooling and transporting the metal particles in the form of a fluidized bed formed in the conveyor. The invention also relates to the installation thereof.

An installation for the production of metal powders is provided including a gas atomizer comprising an atomization chamber having a top and a bottom, an atomization nozzle, positioned at the top of the chamber, through which liquid metal can flow, a gas sprayer, adjacent to the nozzle, through which gas can be jetted on the liquid metal and an opening at the bottom of the atomization chamber for discharging the metal powder, a double pipe heat exchanger comprising an inner pipe and an outer pipe, the two pipes being concentric, the inner pipe being connected to the opening at the bottom of the atomization chamber and the outer pipe being connected to the gas sprayer of the atomizer.

A corresponding process is also provided.

A method and system for recovering a high yield of low carbon ferroalloy, e.g., low carbon ferrochrome, from chromite and low carbon ferrochrome produced by the method. A stoichiometric mixture of feed materials including scrap aluminum granules, lime, silica sand, and chromite ore are provided into a plasma arc furnace. The scrap aluminum granules are produced from used aluminum beverage containers. The feed materials are heated, whereupon the aluminum in the aluminum granules produces an exothermic reaction reducing the chromium oxide and iron oxide in the chromite to produce molten low carbon ferrochrome with molten slag floating thereon. The molten low carbon ferrochrome is extracted, solidified and granulated into granules of low carbon ferrochrome. The molten slag is extracted, solidified and granulated into granules of slag.

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 device, 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 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 ?m 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.

A method for preparing metal powder by water atomization is disclosed. The method includes the steps of smelting, atomization, separation and drying, and the metal powder is freeze-dried in the drying step. Experiments show that freeze-drying is an important factor affecting oxygen content indexes of copper and copper alloys, and can be applied to the preparation of copper and copper alloy powder and even metal powder with low oxygen content. The method further considers all the details that may cause oxidation during the atomization process, and takes comprehensive measures to greatly reduce the probability of oxidization of copper and copper alloy powder, so that the oxygen content and oxidation of the water atomized powder are effectively reduced, and the water atomized powder is not easy to be oxidized during long-term storage.

A lead-based alloy containing alloying additions of bismuth, antimony, arsenic, and tin is used for the production of doped leady oxides, lead-acid battery active materials, lead-acid battery electrodes, and lead-acid batteries.