Refused derived fuel from municipal solid waste used as an alternative fuel during the iron ore sinter process

Abstract In order to reduce the fuel cost of the steel company and dispose municipal solid waste (MSW), refused derived fuel (RDF) was prepared by MSW carbonization and used as an alternative fuel in the sinter process of the steel company. The calorific value of MSW carbonized under 500 oC (designed as RDF-500) was 25.47 MJ·kg-1, and its ash content and volatile matter was 15.1% and 21.3%, respectively. The properties of RDF-500 were more close to those of coke breeze. Hence, RDF-500 was regarded as the alternative fuel in the iron ore sinter process. The experimental results demonstrated that the qualities (yield, tumble strength index and shatter strength index) of the sintered ore were not significantly decreased until the replacement ratio of RDF-500 was above 20%. The tumble strength index and shatter strength index of the sintered ore under 20% RDF-500 replacement were 62.58% and 60.93%, which were little lower than those with full coke breeze (65.78% and 63.43%). RDF-500 contained more volatile matter, which was not useful for forming liquid phase of mineral matter. Thus, the duration of temperature for mineral melting (DTMM) and liquid phase formation area (LPFA) were decreased when RDF-500 was used to replace part of coke breeze, which accounted for the decrease of the qualities of sintered ore. In addition, more CO and NOx were emitted and less SO2 was formed when 20% coke breeze was replaced with RDF-500.