A process of producing silicon-containing materials includes converting a gas to a super-heated state in which it is at least partly in plasma form, and contacting the superheated gas with a silicon-containing first starting material to form a mixture including the gas and silicon, where-in the silicon-containing materials are produced by adding to the gas or the mixture a second starting material that can enter into a chemical reaction directly with the silicon in the mixture, or breaks down thermally on contact with the superheated gas and/or the mixture, and steps a. and b. are effected spatially separately from one another.

A method for manufacturing silicon nitride from waste silicon kerf includes the steps of reducing agglomerations in the waste silicon kerf, adding and mixing calcium oxide to the waste silicon kerf, placing the waste silicon kerf in a ceramic crucible, placing the ceramic crucible in a furnace, heat treating the waste silicon kerf in the ceramic crucible in the furnace under a vacuum to disassociate silicon dioxide into silicon and silicon monoxide, and heat treating the waste silicon kerf in the ceramic crucible in the furnace while introducing nitrogen gas into the furnace to create the silicon nitride.