Air pollution control (APC) residues from municipal waste incineration contain considerable amounts of water-soluble heavy metal compounds which can cause environmental problems. Therefore, a satisfactory and efficient detoxification technology is required. A thermal process via sintering has been developed that is capable of forming two major fractions of sintered products-that is, a small fraction in which the volatile heavy metals are concentrated for recycling or disposal and a major solid particle fraction that is more stable. This result has been obtained by heating the APC ash up to 850 degrees C with a high efficiency processing system. This novel process has been demonstrated in a large experimental facility that includes a 100 kW regenerative burner. The approach is based on the application of a regenerative heating concept to achieve an economic and efficient process. Thus, the hazardous material which is causing a problem when landfilled can be converted to a better quality product either for utilization by the construction industry or for disposal at lower cost.