Fundamental research of hazard-free treatment for MSW incineration fly ash by metallurgical sintering

MSW incineration fly ash should be treated safely because it is one of acknowledged hazard solid wastes.Metallurgical sinter has a similar high temperature environment as melting treatment,therefore,it is proposed as hazard-free treatment for MSWI fly ash.Experiments are carried out to investigate the pelleting properties of fly ash and the seperation and solidification of heavy matals in MSWI fly ash iron-bath melting process.The results show that adding 8% cement and 1% agent for solidification,the compressive strength of fly ash pellets is 600～700N/bellet when its curing period is about 8～11d,achieving the demands for transporting and sintering.By iron-bath melting,more than 90% Mn and Fe in MSWI fly ash are removed and solidified in iron phase,and the distribution ratio of Cr and Cu in iron phase is beyond 70%.The leaching toxicity of molten slag are tested,and the leaching toxicity of all the metals can reach the standard.All the results indicate that the hazard-free treatment for MSWI fly ash by metallurgical sintering is feasible.