Method for cleaning SiO2 grain

A method for the cleaning of SiO2 grain is known whereby SiO2 grain comprising contaminations is heated to a temperature at which the contaminations soften or form melting agglomerates with the SiO2 grain, thus separating the contaminations and the SiO2 grain. On this basis and to specify a method which achieves high grain purity at comparatively little expenditure of time, material and costs, and to provide a simple device suitable for the implementation of the method, it is proposed according to the invention that the SiO2 grain is fed to and heated in a gas stream which is directed towards an impingement plate, the SiO2 grain being accelerated in the direction of the impingement plate such that softened contaminations or melting agglomerates adhere to the impingement plate and cleaned SiO2 grain is removed from the impingement plate. A simple device suitable for the implementation of the method is provided with a burner into which a burner gas is introduced for a, burner gas flame, and a feeder device by means of which the SiO2 grain containing contaminations is fed to the burner gas or the burner gas flame, as well as an impingement plate toward which the burner gas flame is directed.