摘要
硫酸盐类工业固废造成的环境污染和资源浪费问题引起了国内外学者的广泛关注,当前中国两种典型的硫酸盐类固废(电解锰渣和磷石膏)堆存量巨大,造成严重的环境污染,其无害化与资源化利用刻不容缓。依据电解锰渣、磷石膏两种固体废弃物的特性,利用电解锰渣和磷石膏结合矿渣制备复合胶凝材料,探究了磷石膏和水泥不同掺量对复合胶凝材料硬化体力学性能的影响。通过XRD、SEM和EDS分析了硬化体的物相组成和微观形貌变化特征,同时对硬化体进行毒性浸出测试。结果表明:硬化体各龄期强度随着水泥掺量增加而增大,硬化体各龄期强度随着磷石膏掺量增加而减小。复合胶凝材料较优配合比(质量分数)为电解锰渣为50%、磷石膏为20%、矿渣为30%,水泥外掺12%的硬化体28 d抗压强度为27.1 MPa,硫酸盐固废复合胶凝材料的水化产物主要为水化硅酸钙(C-S-H)凝胶和钙矾石(AFt)。养护至28 d的硬化体浸出液中可溶性Mn^(2+)、NH_(4)^(+)-N、PO_(4)^(3-)和重金属离子浓度稳定后满足GB 8978—1996《污水综合排放标准》的排放要求。
The environmental pollution and resource waste caused by sulfate industrial solid wastes have attracted wide⁃spread attention from scholars at home and abroad.At present,two typical sulfate solid wastes in China,electrolytic manga⁃nese slag and phosphogypsum,have huge stockpiles and cause serious environmental pollution,so it is urgent to realize their harmless and resourceful utilization.Based on the characteristics of two kinds of solid wastes,electrolytic manganese slag and phosphogypsum were used to prepare composite cementitious materials by combining slag with electrolytic manga⁃nese slag and phosphogypsum,and the effects of different blending amounts of phosphogypsum and ordinary silicate cement on the mechanical properties of the composite cementitious materials were investigated.The physical composition and micro⁃scopic morphological changes of the hardened body were analyzed by XRD,SEM and EDS,and the toxicity leaching test was also conducted on the hardened body.The results showed that the strength of the hardened body at each age was in⁃creased with the increase of cement dosing,and the strength of the hardened body at each age was decreased with the in⁃crease of phosphogypsum dosing.The 28 d compressive strength of the composite cementitious materials with the ratio of 50%electrolytic manganese slag,20%phosphogypsum,30%slag and 12%cement admixture could reach 27.1 MPa,and the hydration products of sulfate solid waste composite cementitious materials were mainly hydrated calcium silicate (C-S-H) gel and calcium alumina(AFt).The concentration of soluble Mn^(2+),NH_(4)^(+)-N,PO_(4)^(3-) and heavy metal ions in theleachate of the hardened body maintained to 28 d met the discharge requirements of GB 8978—1996“ComprehensiveWastewater Discharge Standards”after stabilization.
作者
余舟
何兆益
唐亮
何盛
肖海鑫
肖懿训
YU Zhou;HE Zhaoyi;TANG Liang;HE Sheng;XIAO Haixin;XIAO Yixun(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Traffic&Transportation,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2024年第4期90-97,共8页
Inorganic Chemicals Industry
基金
重庆市科技局重点项目(cstc2021jscx-jbgs0029)。
关键词
硫酸盐类固废
复合胶凝材料
力学性能
水化硬化
毒性浸出
sulfate solid waste
composite cementitious materials
mechanical properties
hydration hardening
toxic leaching
