Preparation Of Eco-cement Clinker From Municipal Solid Waste Incinerator Fly Ash

The feasibility of using the municipal solid waste incinerator （MSWI）fly ash as a material for Alinite based eco-cement clinker was investigated.The influences of the proportion of MSWI fly ash in the raw material andchloride on the sintering product were studied. The transfercharacteristics of chlorine in the process of sintering clinker also wasstudied.MSWI fly ash can be used as a raw meal for Alinite basedeco-cement clinker. The proper sinter temperature was about1150℃. Itwas found that the28days compressive strength of the cement mixedwith20%fly ash reached46.58MPa. The addition of MSWI fly ash to20%amount of total material is optimal for the formation of Alinite phase.It was also found that fly ash can promote the formation of Alinite phasewhen the amount less than20%. The color of the clinker changed fromwhite to brown with the increase of fly ash dosage in the meal, making itnot be a kind of white cement.It was found that the formation of Alinite phase could be significantly promoted by the chloride. C₂S and C₁₂A₇·CaCl₂transformedto Alinite with the chloride addition increased. At the same time, the burnability of the raw meal was improved and the decomposition temperatureof CaCO₃was decreased.Experimentally results showed that the volatilization and solution ofchloride increased with the raise of chloride content in the raw mix. At thesame time, the volatilization rate of chloride in the process of sinteringclinker was decreased. The volatilization rate of chloride was high whenthe chloride addition was less than3%, and the rate kept below45%withthe chloride content higher than5%. The dissolution rate of chloridedecreased firstly and increased later in the sintering process. When thecontent of chloride up to5%, the dissolution rate reached a minimumvalue of26.6%.