Abstract: The invention concerns the area of ceramics an relates to a method for separating impurities from silicon carbide, said method being applicable to SiC powders from grinding sludges, and to temperature-treated and purified silicon carbide powder. The aim of the invention is to provide a method with which different impurities are substantially completely removed using a simple and economical process. This is achieved by a method in which pulverulent SiC waste products that have a mass percent of SiC of at least 50% and an average grain size d50 ranging from 0.5 to 1000 ?m and have been subjected to a temperature treatment and cooled are mechanically treated and physically separated. The physically separated SiC powder is then divided into two fractions, one of which has a mass of impurities that is greater than the mass of impurities in the other fraction at least by a factor of 2.

Abstract: The invention provides a boron suboxide composite material comprising boron suboxide and a secondary phase, wherein the secondary phase contains a metal selected from the group of gold, silver and copper and alloys based on or containing one or more of these metals. Moreover, the metal or alloy is present in the material in an amount of less than about 20 volume %, and preferably less than about 6 volume %.