地聚合材料固化处理垃圾焚烧飞灰

以垃圾焚烧飞灰和高岭土为主要原料,氢氧化钾为碱激活剂制备了地聚合材料,当焚烧飞灰的掺加量在70%时,其28 d抗压强度可达19.36 MPa。重金属浸出实验表明,地聚合物材料对垃圾焚烧飞灰中的重金属有明显的固化效果,在28 d时基本无溶出。SEM结果表明,地聚合材料的断面结构与力学性能和固化效果相关,XRD和FTIR的分析结果表明,焚烧飞灰和高岭土在碱的激发下生成新的硅铝酸盐聚合物,所得地聚合材料为无定形态。

Study on solidification of municipal solid waste incineration fly ash by geopolymer

Municipal solid waste incineration (MSWI) fly ash and kaolin have been employed to prepare a series of geopolymeric matrices, with potassium hydroxide as activator. The compressive strength of the geopolymer could reach to 19.36 MPa when the addition of MSWI fly ash amounted to 70%. The results of toxicity characteristic leaching procedure indicated that geopolymer had excellent solidification efficiency to heavy metals. The images of scanning electron microscopy (SEM) showed that the fractured surface structure of matrices was related to the compressive strength and the solidification efficiency. The results of X-ray diffraction (XRD) analysis and Fourier transform infrared spectrum (FTIR) indicated that MSWI fly ash reacted with kaolin to form a new Si-Al polymer under the activation of alkali and that the structure of geopolymer was amorphous.