mill 13 the titanium containing material m is introduced into the coal mill 13 either directly or through the feed conduit 16 and the feed shaft 14 and is ground there as fine as dust together with the coal k fuel b which is prepared in this way passes through the feed 2b and the burner 2a into the combustion chamber 2 there it is burnt with compressed air l supplied through the fresh air conduit 4 flue gas rg forms and flows through the flue gas conduit 7 into the dust filter unit 8 where fly ash or flue dust s entrained by the flue gas is caught and discharged through the fly ash collector 9 the flue gas rg which is then virtually dust free passes to the flue gas desulfurization unit 10 and through the unit 11 for the removal of nitrogen oxides generally referred to as a deno x unit into the chimney 12 the molten ash f collecting on a bottom 2c of the combustion chamber is fed through the discharge line 5 to the wet slag removal equipment 6 and processed into granules g the fly ash s which is collected on the collector 9 can be utilized as usual the use of up to 3 of titanium containing material m with a titanium dioxide content of more than 50 is advantageous additives or impurities contained in this material m such as for example heavy metals are melted insolubly into the granules g that are obtained these granules g from the melting chamber can be used in the customary manner as a construction material in a preferred second exemplary embodiment of the invention in accordance with fig2 the combustion unit 1 with the slag tap furnace has a fly ash return 20 this.