飞灰添加量对矿渣基回填胶凝材料水化机理以及重金属固化/稳定化效果影响  

EFFECT OF FLY ASH INCORPORATION ON HYDRATION MECHANISM AND HEAVY METAL SOLIDIFICATION/STABILIZATION EFFECT ON SLAG-BASED BACKFILLFING CEMENTITIOUS MATERIALS

作　　者：赵楚峒 关艳艳 张泽 王晓娜 高明 吴川福 汪群慧 ZHAO Chutong;GUAN Yanyan;ZHANG Ze;WANG Xiaona;GAO Ming;WU Chuanfu;WANG Qunhui(School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学能源与环境工程学院,北京100083

出　　处：《环境工程》2023年第12期213-220,189,共9页Environmental Engineering

基　　金：国家重点研发计划项目(2021YFE0112100)。

摘　　要：采用飞灰协同冶金固体废物(高炉矿渣、钢渣以及脱硫石膏)制备飞灰-矿渣基胶凝材料代替水泥作为采空区的回填材料,并探究了飞灰掺入量对胶凝体系水化机理及重金属稳定化效果的影响。结果表明:胶凝体系飞灰掺入量较少时(10%),会抑制体系早期(3 d)水化产物的生成,降低固化体的抗压强度;飞灰的碱激发作用会在一定程度上促进水化产物钙矾石的生成,对养护结束(28 d)时固化体的抗压强度提升具有促进作用;当胶凝体系飞灰掺入量较高时(25%),会严重抑制胶凝体系水化进程,但其产品抗压强度仍高于矿区采空区对胶凝材料的要求。另一方面,飞灰-矿渣基胶凝体系对飞灰中重金属的稳定化效果良好,除了飞灰掺入量为25%处理组的Zn浸出浓度接近水泥胶砂(GB/T 30810—2014)标准限制外,其他处理组(飞灰添加量为0%~20%)重金属浸出量均满足标准限制。因此,在掺入量合适的情况下,以飞灰作为矿区回填胶凝材料是一种理想的飞灰建材资源化方法。In this study,fly ash-slag-based cementitious materials were prepared from fly ash co-metallurgical solid wastes(blast furnace slag,steel slag,and desulfurization gypsum)instead of cement,as backfilling materials for the mining area,and the effect of fly ash incorporation on the hydration mechanism and heavy metal stabilization effect of the cementitious system was investigated.The results showed that a low amount of fly ash(10%)in the cementitious system would inhibit the generation of hydration products in the early stage(within 3 days)of the system and reduce the compressive strength of the cured body;the alkali excitation effect of fly ash would promote the generation of hydration products,calcium alumina to a certain extent,with a facilitating effect on the compressive strength of the cured body at the end of maintenance(the 28 th day);high amount of fly ash in the cementing system(25%)would seriously inhibit the hydration process of the cementing system,but the compressive strength of the product was still higher than the requirements of the cementing material for mining area.On the other hand,the fly ash-slag-based cementitious system stabilized the heavy metals in the fly ash well,and the leaching of heavy metals in all other treatment groups(with fly ash addition of 0%~20%)satisfied the standard limits,except for the Zn in the treatment group with fly ash admixture of 25%,which was close to the China national standard limit of cementitious sand(GB/T 30810—2014).Therefore,using fly ash as mine backfilling cementitious material is an ideal method,under the appropriate admixture amount.

关 键 词：生活垃圾焚烧飞灰 冶金固体废物 固化/稳定化 胶结填充 重金属 

分 类 号：X799.3[环境科学与工程—环境工程] X756[矿业工程—矿山开采] TD80