Considerable amounts of ash, dust and slag evolve within the activities of the Austrian industry and trade. These byproducts or residues are often defined as waste. They contain often unfavourable components for further processing or application, e.g. heavy metals, carbon, chlorine, alkali metals, etc. However, they also show interesting hydraulic properties after proper processing or they contain suitable amounts of calcium and other elements and can be used as raw materials in the cement process. The use of waste to replace raw material might yield a decrease in CO2emissions that are emitted by the decomposition of calcium carbonate. Besides, not only natural resources can be preserved, but also waste can be utilised by substituting natural raw materials and landfill volume can be saved. The goal of the present master thesis was to study the qualification of different waste material such as ash, dust and slag as alternative raw material for the clinker production. Particular emphasis was laid on the selection of a processing method to reduce the chlorine content in an ash which originates from the paper industry under a predefined critical content. Mesh analysis of four ashes of different origin, two slags and a carbon-containing lime powder was conducted, and the resulting fractions were analysed by XRF. Screened size-fractions of the slags within the range 0.315 -0.5 mm and 0.5 1 mm were then magnetically separated. The five ashes were elutriated and the residuum analysed with XRF. It could be shown that a 70 % reduction of the chlorine content in the ash can be achieved, using this method.