重金属离子在水泥砂浆中的浸出性研究

Study of leaching mechanism of heavy metals in cement mortar

采用在生料中掺重金属化学试剂在实验室条件下烧制出的熟料,研究了重金属元素在水泥应用过程中的流向,模拟德国的水槽试验法测试了水泥砂浆中重金属离子Pb、Cd、As和Cr在不同pH值浸出液条件下的长期浸出行为,探讨了酸性条件对重金属浸出的影响。结果表明:Pb、Cd及Cr3+均可以稳定固化在砂浆内部,长期浸出固化率可达99.9%以上;酸性条件可以抑制Cr3+的浸出,促进Cr6+的浸出,对Pb、Cd、As的浸出影响较小。

The clinker prepared by raw meal mixed with chemical reagents of heavy metals was burnt in laboratary condition, and the flow way of heavy metal elements in cement during its application was studied to see the effect of hazard waste materials used in cement kiln. Under different pH conditions, the long-term leaching behaviors of Pb, Cd, As and Cr were tested by simulation of the water bath test method of Germany. The effect of acidic condition on the heavy metal leaching was investigated. The results indicated that Pb, Cd and Cr^3＋ could be solidified by mortar steady and the long-term immobilized ratios were over 99.9%. The acidic condition could inhibit the extraction of Cr^3＋ and accelerate the extraction of Cr^6＋, but little effect on that of Pb, Cd and As.