采用城市生活垃圾焚烧飞灰制备绿色水泥砂浆的可行性研究

Feasibility of Preparing Green Cement Mortar via Municipal Solid Waste Incineration Fly Ash

城市生活垃圾焚烧飞灰(MSWIFA)是城市生活垃圾焚烧产生的副产品之一,处理不当会导致严重的环境问题。采用MSWIFA部分替代水泥制备绿色水泥砂浆(GM)能够实现MSWIFA在建筑材料中的资源化利用。本工作主要研究不同替代率的MSWIFA对GM工作性能、力学性能和耐久性能的影响。此外,本工作还表征了GM的微观孔结构和微观形貌。最后,本工作通过分析1 m 3GM的能耗、碳排放、生产成本,评估了MSWIFA替代水泥制备GM的经济、社会和生态效益。研究表明:(1)MSWIFA的掺入导致GM的抗折强度、抗压强度分别降低了10.54%~29.97%、18.74%~39.54%;(2)硅酸盐水泥可以固化MSWIFA,GM的重金属浸出满足国家规定限值;(3)当MSWIFA的替代率为15%时,1 m 3GM的能耗、碳排放、生产成本分别降低14.90%、14.63%、10.36%,而其工作性能、力学性能、耐久性依然能够满足建筑砂浆要求,表明采用MSWIFA制备GM能够实现该固体废弃物的资源化利用,具有巨大的经济、社会和生态效益。

Municipal solid waste incineration fly ash(MSWIFA)is one of the by-products of municipal solid waste incineration,and its improper disposal can lead to serious environmental problems.Using MSWIFA to partly replace cement to produce green mortar(GM)can realize the resource utilization of MSWIFA in building materials.This work mainly carried out an investigation on the effects of MSWIFA with different substitution rates on the workability,mechanical properties and durability of GM.Furthermore,the micro pore structure and morphology of GM were also explored.Finally,by analyzing the energy consumption,carbon emission and production cost of 1 m 3 GM,the economic,social and ecological benefits of GM produced by replacing cement with MSWIFA were evaluated.It was shown that:(i)due to the incorporation of MSWIFA,the flexural strength and compressive strength of GM were reduced by 10.54%—29.97%and 18.74%—39.54%,respectively;(ii)the heavy metal leaching results of GM could meet the limit value of national standard,which suggested that Portland cement could solidify MSWIFA;(iii)when the substitution rate of MSWIFA was 15%,the energy consumption,carbon emission and production cost of 1 m 3GM could be reduced by 14.90%,14.63%and 10.36%,but its workability,mechanical properties,and durability could still meet the requirements of building mortar.These results indicated that using MSWIFA to produce GM could realize resource utilization of this solid waste,which enjoy great benefits in economic,social and ecologic terms.