添加黄土对含镉冶炼废渣水泥固化效果的影响

Effect of Loess Addition on Cement Solidification of Cadmium-bearing Waste Residue

以黄土和石灰为添加剂研究了含镉废渣填埋用水泥固化的工艺规律,通过毒性浸出试验考察了不同固化条件对固化效果的影响。结果表明,在水泥用量一定的情况下,用低于物料总量25%的黄土部分替代水泥后固化效果变化不大;加入一定量石灰能有效增大固化能力;提高养护温度、延长养护时间有利于增强固化效果。试验条件下固化块的适宜配比为:废渣40%、水泥35%、黄土18%、石灰7%,所制得固化块的镉离子毒性浸出浓度小于0.118 6mg/L,可实现安全填埋。

Technological law of cement solidification of cadmium-bearing waste residue for landfill was studied with loess and lime as additives. The effect of different solidification conditions on curing-effect was investigated by leaching toxicity experiment. The results show that loess addition of less than 25% of total material can partly replace cement without changing curing effect in the case of certain amount of cement. Curing ability can be effectively enhanced by adding certain amount of lime. Increasing curing temperature and prolonging curing time can enhance curing effect. The toxicity leaching concentration of cadmium of curing blocks is 0. 118 6 mg/L below with safe landfilling under the optimum conditions including waste slag of 40%, cement of 35%, loess of 18%, and lime of 7%.