Abstract: Moisture is removed from a fluid waste product or material by pumping the material axially through an elongated porous tube, forcing a gas generally radially inwardly through the tube to effect disintegration of the material, and then directing the material through a perforated duct which receives heated air from a burner unit. As the moisture evaporates from the material, the moisture vapor is separated from the dry solid particles by a separator connected to a suction blower for inducing a draft. The apparatus may also be adapted for treating or drying other materials such as slurries of metallurgical ores and for oxidizing or reducing mineral-type materials in addition to drying finely dispersed metal slurries in the production of powdered metals. Another embodiment of the apparatus is used for burning a fluid waste product or material.