胶结充填采矿协同资源化利用垃圾焚烧飞灰固化机理研究

为确定低成本、安全、高效处置危废城市垃圾焚烧飞灰(MSWI)的方法,以钢渣微粉、矿渣粉、脱硫石膏、垃圾焚烧飞灰和尾砂为充填材料,进行了砂浆流动性能和胶结充填料强度试验,根据胶结充填料强度确定了胶凝材料的最优配比,并通过X射线衍射(XRD),红外(FTIR)和扫描电镜(SEM)分析了净浆试块的微观结构和水化产物。试验结果表明,当垃圾焚烧飞灰掺量为15%、钢渣微粉掺量为4%、脱硫石膏掺量为14%、矿渣粉掺量为67%时,料浆的流动度为260 mm,满足自流型胶结充填的流动性需求,充填料试块28 d的抗压强度为24.54 MPa,满足矿山充填强度要求;充填料试块养护28 d重金属离子浸出浓度全部低于饮水标准;冶金渣-垃圾焚烧飞灰胶凝材料水化产物主要有钙矾石、C—S—H凝胶和Friedel盐。

Study on the Mechanism of Synergistic Utilization of Fly Ash from Solid Waste Incineration by Cemented Filling Mining

In order to determine the research method of low-cost，safe and efficient disposal of municipal solid waste incineration fly ash (MSWI)，we conducted the flow performance and strength test of filling material which were made of slag powder，slag powder，gypsum，incineration fly ash.The optimal mixing ratio of cementitious material was determined according to the strength of cement filler.The microstructure and hydration products of the cement paste were analyzed by X-ray diffraction (XRD)，infrared (FTIR) and scanning electron microscopy (SEM).The results show that when the content of waste incineration fly ash is 15%，the content of steel slag is 4%，the content of desulphurization gypsum is 14% and the slag content is 67%，the fluidity of the slurry is 260 mm，which satisfies the liquidity requirement of the self-flow cementation filling，and the compressive strength of the filling material is 24.54 MPa for 28 days，which satisfies the requirement of filling strength of the mine.The leaching concentration of heavy metal ions for 28 days was all lower than that of drinking water.The hydration products of Metallurgical slag-incineration fly ash cementing material are mainly ettringite，C-S-H gel and Friedel salt.