ZnO loaded ceramic filters can be applied for the desulphurization of hot coal gases. These filters consist of a matrix (mullite, quartz) and a porous active layer fitted tightly to the matrix. It could be proved that the affinity of the Zn 2 + containing components to S 2 - decreases in the order ZnO-70 > ZnO-3 > Zn 2 SiO 4 > ZnAl 2 O 4 . Solid state chemical qualities as well as the porosity of the pellets play a role. Qualitatively and quantitatively phase analyses were performed mainly by X-ray methods.