Abstract: When fine filter dust is melted in conventional crucible or induction furnaces, a great deal of dust is generated once again. Compression of the dust is highly complex and is not always possible. According to the invention, the filter dust is collected in a dust-tight top chamber located upstream from the inlet opening of a melting aggregate that is thermally connected to a combustion chamber. The dust particles in the top chamber sink due to the effect of gravity in the melting aggregate and are melted therein. The procedure can be supported by an additional pressure gradient along the melting aggregate. The discharge of dust is largely avoided. The process is also suitable for vitrifying contaminated dust in particular.