In Japan the municipal solid waste (MSW) incinerator dust has been assigned to one of the strictly regulated categories which should be treated in accordance with the law. In order to reduce its volume and decompose hazardous dioxin, "melting" the dust is the most practical method among the authorized ones. Daido Steel had installed the DAP system where the arc is the heat source to melt the dust as the mixture with the ash from the MSW incinerator, because the dust itself possesses the chemical composition and physical properties not fit for its arc melting. The new system with an oxygen burner was designed to melt down the dust only at extremely high temperatures. The pilot plant in-house with the capacity of 1.2ton/day passed successfully the 100 day endurance test imposed by the authorities.
