At the plant of RHI AG in Hochfilzen froth flotation has been used to process magnesite for 30 years until 1992. The superfine-grained flotation slurry was deposited in tailings ponds. Now this waste material is supposed to be further processed and redirected into the manufacturing process. The usable quantity of waste material amounts to approx. 40,000 t/year with an average moisture content of 25%. A sustainable and economic utilization of the former tailings material result in a slower exploitation of the primary magnesite deposit and in an extension of the life span of this long-established industrial plant. It has been examined, whether high quality products can still be manufactured when adding the tailings to the feed material of the processing plant. The variations in moisture content and chemical composition will challenge the extraction and the following mineral processing steps. Due to these difficulties a detailed study was conducted to test and evaluate possible wet, dry and moist processing techniques. Because of the high water content it is best to process the flotation tailings in a moist processing method.