PURPOSE: To easily reduce and refine metal oxides, by impregnating metal oxides with acetic acid in which saccharides are dissolved, by subjecting the above to heat treatment for reduction and then to pulverization, by mixing the resulting powder with inorganic reducing agents, etc., by allowing the resulting mixture to react by the addition of sulfuric acid, and then by applying heat treatment to the above.

CONSTITUTION: Saccharides such as cane sugar, etc., are added to acetic acid to undergo dissolution. Single or plural metal oxides are impregnated with the resulting dissolved substance, which is subjected to heat treatment to about 500W800°C. The above heat treatment is continued until generation of decomposition gas is stopped, so that above-mentioned metal oxides are reduced into metals or alloys. Subsequently, the above reduced metals or alloys are pulverized into powder. The above metal or alloy powder is mixed with reducing agents such as borax, acetic soda, etc., and the resulting mixture is allowed to react by the addition of sulfuric acid. Thereafter, the powdered metals or alloys are heated slowly to undergo drying and solidification and further heated to about 900W1,200°C to undergo melting, so that products can be completely refined.