Abstract: A thermal dechlorinating apparatus for collected ash, having a vertically elongated cylindrical apparatus body, a collected ash inlet and a collected ash outlet which are provided on the apparatus body and spaced in a vertical direction thereof, an inlet port for heated air provided on the portion of the apparatus body between the inlet and the outlet, an exhaust gas outlet provided on the portion of the apparatus body above the collected ash inlet, a rotary shaft provided along the axial direction of the apparatus body, a screw provided on the rotary shaft, and heating means provided on the portion of the apparatus body between the collected ash inlet and the collected ash outlet. Heated air is led into the apparatus body through the heated air inlet port. A stirred fluidized layer is formed in the portion of the apparatus body above the heated air inlet port, and a moving layer is formed below the heated air inlet port.

Abstract: Incineration flyash is treated by reducing the organic chlorine compounds contained in the flyash. A cylindrical body equipped with a rotating shaft having a screw conveyor and agitating blades for conveying and agitating the flyash is filled to at least a 75 vol % charge so that contact of the flyash with oxygen is made as small as possible. The flyash is subjected to agitation and heat-treatment at 300.degree. C. or higher. The cylindrical body has a feeding port for the waste incineration flyash and a discharging port for the discharge of the treated flyash. The screw conveyor is at the introducing part and has a pitch that is successively reduced toward the agitating part for charging the flyash in the agitating part at a greater vol. % than that which occurs in the introducing part.