Abstract: A process for the recovery of copper from its ores by conventional procedures requiring heat in which the source of heat is microwave energy. The microwave energy is used to selectively heat the copper compounds, such as sulfidic and oxidic compounds, in the ore, as respects the gangue, to convert the compounds into other compounds, such as oxides and chlorides, from which copper is more readily recoverable.

Abstract: Copper powder is produced from brass by reacting the brass with hydrochloric acid in an oxygen-free atmosphere at a temperature of at least 70.degree. C. until the non-copper metals and impurities of the brass are dissolved, oxidizing at least 10 percent by weight of the resulting copper to copper oxides, grinding the copper-copper oxide to a powder and removing the copper oxides of the powder to obtain a pure copper powder.

Abstract: A process for the recovery of molybdenum and rhenium from their sulfide ores which comprises subjecting the ores to microwave energy in the presence of oxygen to selectively heat the sulfides to convert them to oxides, and recovering the formed oxides. Alternatively, the sulfides in the ore are selectively heated with microwave energy in the presence of chlorine to convert them to the corresponding chlorides, and the metals recovered from the chlorides.

Abstract: A process for the recovery of nickel, cobalt or manganese from their oxides or silicates wherein such process, which requires the application of heat, is improved by utilizing microwave energy as the source of heat. The microwave energy may be utilized to cause the reduction of these values enabling such reduced values to then be recovered by conventional leaching processes. The microwave energy may also be used in conjunction with the chlorination of such values to produce their chlorides which are subsequently separated from the gangue and then processed by conventional means to obtain the metal values.