Method and system for producing silicon

A device for processing a substance, its oxide and/or its sulphide, the substance being a metal or metalloid, the device comprising

• a reaction chamber and an expansion chamber;
• a plasma generator device, arranged to emit a plasma stream into the reaction chamber, the plasma stream comprising the substance, its oxide and/or its sulphide;
• a first material provision means, arranged to provide material comprising the substance, its oxide and/or its sulphide to the plasma generator device;
• a gas provision means, arranged to provide an inert and/or reducing gas to the reaction chamber;
• a DeLaval nozzle, arranged to convey gases from the reaction chamber to the expansion chamber, the DeLaval nozzle being arranged to lower the temperature of the gases passing through the DeLaval nozzle to below the condensation temperature of the substance, its oxide and/or its sulphide, so that said substance, oxide and/or sulphide entering the DeLaval nozzle in gaseous form as a result from passing through the DeLaval nozzle condenses into a liquid or solid phase;
• a vessel, into which the condensed substance is directed by the DeLaval nozzle;
• and
• a third material provision means, arranged to provide at least one of hydrogen and a chemically non-reactive species, such as an inert gas, to the expansion chamber.