水洗脱氯飞灰掺加制备混凝土实心砖的资源化利用研究

Investigation on Resource Utilization of Water-washed Fly Ash Incorporated into Solid Concrete Brick

为探究生活垃圾焚烧飞灰制备混凝土实心砖资源化利用的可行性,以水洗脱氯飞灰为掺料,掺加量为8.3%、20.75%、33.2%、41.5%制备了混凝土实心砖,从抗压强度和重金属浸出特性评估了实心砖的工程质量和环境风险。结果表明,水洗脱氯飞灰的重金属稳定性增强,有利于后续资源化利用。掺加8.3%水洗脱氯飞灰的混凝土实心砖,其抗压强度满足《混凝土实心砖》(GB/T 21144-2007)强度等级MU 15;Pb、Zn、Cd、Cr、Cu浸出毒性远低于《危险废物鉴别标准浸出毒性鉴别》(GB 5085.3-2007)的标准限值。控制水洗脱氯飞灰掺加量不超过10%,在满足工程强度要求的同时可保证其环境安全。

Water-washed municipal solid waste incineration(MSWI)fly ash was incorporated into solid concrete brick to investigate the resource utilization of MSWI fly ash.Solid concrete brick samples with 8.3%,20.75%,33.2%and 41.5%of water-washed fly ash were prepared.Compressive strength and heavy metal leaching toxicity of the brick samples were tested to evaluate the engineering quality and environmental risk,respectively.The results show that heavy metal stability of fly ash was improved after water-washing,which is beneficial to resource utilization.The compression strength of solid concrete brick with 8.3%of water-washed fly ash met the requirement of class MU 15 according to Solid Concrete Brick(GB/T 21144-2007).Leaching toxicity of Pb,Zn,Cd,Cr,Cu were far lower than the limit values of Identification Standards for Hazardous Wastes-Identification for Extraction Toxicity(GB 5085.3-2007).It is suggested that the addition of water-washed fly ash should be no more than 10%to ensure the engineering strength and environmental safety of solid concrete brick.