矿区炼金废渣的固化/稳定化处理

通过对金矿矿区炼金废渣的酸中和能力、净产酸量及浸出毒性实验，测定了废渣的产酸潜力及重金属砷、镉、铅、锌的总量和它们的浸出量。为了合理处置矿区炼金废渣，并为矿区重金属污染土壤的修复提供技术支持，采用石灰、粉煤灰、堆肥化污泥作为添加剂对废渣进行固化/稳定化处理；通过浸出毒性实验对固化/稳定化处理效果进行综合分析，试图寻求一种最佳的稳定剂。结果表明，无论是单独添加石灰、粉煤灰或者堆肥化污泥还是两两组合混合添加，样品浸出液的pH都有升高，As、Cd的浸出浓度都有明显下降，而且两两组合添加比单独添加的固化/稳定化处理效果更好。在两两组合添加中，粉煤灰混合堆肥化污泥的处理效果最好，浸出液的pH值达到7.82，As、Cd的浸出率分别下降72.0%和72.2%。说明粉煤灰混合堆肥化污泥处理炼金废渣效果最佳，同时具有以废治污的资源化生态效能。

Solidification/stabilization treatment of gold mining waste residue

The acid producing potential, the gross amount of heavy metals As, Cd, Pb, Zn and their leaching concentrations of Au smelting wastes from gold mining area were tested by acid neutralizing capacity, net acid generation test and leaching toxicity experiment. In order to treat waste residues reasonably, and to provide the technical support for heavy metal contaminated soils remediation, the lime, fly ash and composted sludge were used to solidify/stabilize the waste residues. Leaching toxicity test of solidification/stabilization treatments were applied to evaluate the effect. The results showed that the pH of the leaching solution of treated samples increased, and As, Cd leaching concentrations decreased significantly whether using lime, fly ash, composted sludge alone or pairwise combination. Moreover, the solidification/stabilization treatment effects of the pairwise combination for additives were better than the separate one. For the combination of two additives, fly ash mixed with composted sludge showed the best treatment effect, the leaching solution pH reached 7.82, and the leaching rate of As and Cd decreased 72.0%, 72.2%, respectively. The results showed that fly ash mixed with composted sludge had the best effect for treating waste residues, and it discovered an alternative way of utilization of wastes as resource and remediation of heavy metal polluted mining area.