Abstract: A method for reducing the sulfur oxide content of a gaseous effluent resulting from the oxidation of sulfur-containing materials, such as fuels, which method provides for oxidation of such materials in a fluidized bed reactor in the presence of one or more metallic oxides reactive with sulfur oxides to form metallic sulfates. The method is carried out at temperatures sufficient to effect substantial oxidation of the sulfur in sulfur-containing substances yet insufficient to melt or dissociate appreciable amounts of the metallic sulfate reaction products formed.The method is particularly useful in the oxidation of coal using an alumina bearing non-refractory clay. Gaseous sulfur oxides released in the oxidation of coal under the conditions described in the invention will combine with the alumina content of the clay to form aluminum sulfate which remains in the bed medium along with coal ash and other non-combustible materials.