金尾矿混凝土中重金属长期浸出行为研究OA北大核心CSTPCD

An investigation was undertaken to assess the potential for heavy metal leaching from gold tailings(GTs)when used GTs as fine aggregate for concrete.The leaching behavior in different pH leaching solutions and long-term leaching features of gold tailings concrete were studied.A kinetic model was used to predict the total amount of heavy metal leaching that will occur in next thirty years.The results reveal that the levels of Ba,Cd,Cr,Pb,Mn and Cu in GTs exceed the natural levels of these elements found in Chinese soil.Significantly,the leaching of Ba,Cd,Pb,Mn and Cu is more evident.GTs content shows a positive correlation with the leaching amount of heavy metals,and the cumulative leaching amount of heavy metals drops dramatically after 16 d.Based on 30 years leaching amount prediction,the leaching amount of Pb,Cu and Ba is 2～3 mg/L,while the leaching amount of Cd,Cr and Mn is less than 1 mg/L.These findings indicate that the GTs is sufficiently cured in concrete,thereby reducing the risk of long-term leaching of heavy metals.