膏体矿井充填对地下水质影响的试验研究

Experimental Study of the Effect of Paste Filling in Mined-out Area on Underground Water Quality

为了探讨膏体矿井充填是否会对地下水质造成污染,用尾砂、水淬渣、水泥按6∶2∶1的比例制成膏体试块在水中浸泡.浸泡不同时间段后,分别取样送往水质监测部门.根据其分析结果,运用多目标决策法判断试验水样的水质优劣,并对水样中部分监测项目(砷、钙、钡、总硬度)监测结果的奇异变化作了回归分析.结果表明:膏体试块在水中浸泡45 d以内水质为Ⅰ级,45 d后为Ⅱ级;说明膏体不会对地下水质造成污染,用于井下充填是安全、可行的;适当增加膏体中尾砂比重和粒级的合理配比可使水中重金属离子含量下降,水质得到进一步改善.

To investigate the effect of paste filling on underground water quality,paste test block is made by tails,water quenching slag,and cement in the ratio of 6∶2∶1,then immerged them into water.After separating different periods of time and then sending water samples to water quality monitoring department to test.According to the results of its monitoring,we use the multi-object decision-making method to estimate water the water quality.Aiming at the problem of sudden change of the monitoring items（arsenic,calcium,barium,and total hardness）,we performed a regression analysis,showing that,for paste test block immersing in water within 45 days,water quality grade isⅠ,for those more than 45 days,the water quality grade is Ⅱ,indicating that the paste used to backfill will not cause pollution of underground water.Appropriate increase in the proportion of paste tailings and in a reasonable ratio of grain size can decrease the concentration of heavy metal ions in water,making water quality further improved.