Effects of SiO_2 on Melting and Solidification Characteristics of Fly Ash from Refuse Incinerator

The effect of adding different contents of SiO_2 in fly ash on melting and solidification,including the change of melting temperature,volatilization rate and fixed rate of heavy metals was studied.The results showed that the discrepancy of melting temperature and volatilization rate is about(70 ℃) and 20.7%,respectively,with adding of 1% and 10% SiO_2 in fly ash.The volatilization rate is little affected by more content of adding SiO_2 on the higher temperature.Adding SiO_2 in fly ash can increase the fixed rate of Pb and affect Cu and Cd indistinctively,but decrease the fixed rate of Zn instead.In conclusion,the temperature is one of the main influence factors and adding more content of SiO_2 can neither increase the fixed rate of heavy metals nor decrease the volatilization rate.