| Through the experiments of leaching and melting on the fly ash of medical wastes, the influence of leaching time, L/S, pH and grain size on the leaching characteristics of heavy metal and the effect of melting on the stabilization of fly ash are studied. Results show that, following the leaching time extending, the leaching concentrations of heavy metals and lixiviate toxicity of heavy metals increase in the fly ash. When the ratio of liquid and solid add, the leaching concentrations of heavy metals obviously become big, and the Cd's leaching concentration is the biggest, when the ratio of liquid and solid is 90, the Cd's leaching ratio exceed the percent of 70. At the time pH is about 7, the leaching concentrations of heavy metals are the lowest. When the grain size is the bigger or little, the leaching concentrations of heavy metals are lower, however when the grain size is 250-900 μm, the concentrations are higher. After fly ash melt in the high temperature, the lixiviate toxicity of heavy metals greatly reduce, which explains that the effect of melting on heavy metals' stabilization is very good. |
