硅灰对城市固体垃圾焚烧飞灰熔融特性的影响

Effect of silica fume on melting characteristics of MSWI fly ash

为了实现"以废治废",将硅灰和城市固体垃圾焚烧飞灰按照一定的质量比制备为混合灰,探讨硅灰质量分数和热处理温度对混合灰熔融特性的影响;利用X射线衍射仪、扫描电子显微镜和能谱仪表征混合灰热处理后产物;采用电感耦合等离子体质谱仪检测混合灰热处理后产物中重金属质量分数和氯元素浸出质量浓度。结果表明:硅灰质量分数为20%~30%、热处理温度为1300℃时,四元碱度约为1(呈中性),混合灰的失质量率与减容率达到最大值,混合灰热处理后产物为均一相无晶玻璃,混合灰热处理后的玻璃体产物中的重金属与氯元素的浸出毒性基本消失。

In order to realize"waste control with waste",silica fume and municipal solid waste incineration fly ash were prepared into mixed ash according to a certain mass ratio,and the effects of silica fume mass fraction and thermal treatment temperature on the melting characteristics of mixed ash were investigated.The product after thermal treatment of mixed ash was characterized by X-ray diffractometer,scanning electron microscope and energy dispersive spectrometer.The mass fraction of heavy metals and leaching concentration of chlorine in the mixed ash after thermal treatment were determined by inductively coupled plasma mass spectrometer.The results show that when the mass fraction of silica fume is 20%~30%and the thermal treatment temperature is 1300℃,the quaternary basicity is about 1(neutral),the mass loss rate and volume reduction rate of mixed ash reach the maximum,the product of mixed ash after thermal treatment is homogenous amorphous glass,and the leaching toxicity of heavy metals and chlorine elements in the glassy product of mixed ash after thermal treatment basically disappears.