初始含水率及固结特性对湿法磷石膏堆场渗滤液产量的影响

目前我国的大部分磷石膏采用堆存处置,但对磷石膏等工业固废堆场渗滤液产量的研究较少。从磷石膏的水分存在形式及变化分析出发,通过固结实验确定孔隙水的沉降挤出性能,建立磷石膏堆场水量平衡分析模型,对影响渗滤液的各因素进行分析,按照水量平衡分析法提出渗滤液计算公式,演算了某含水率条件下各阶段的渗滤液产量、不同含水率条件下和不同计算方法的总渗滤液产量,并进行了分析。分析表明,磷石膏堆场运行初期需要补充新鲜水量才能保证堆场正常运行,随时间的增加渗滤液产量逐渐增加,但各阶段的渗漏液产量与整个运行周期内的平均产量计算结果相差较大,整个周期内总渗滤液产量随磷石膏的饱和初始含水率增大而减少。经过对各计算公式的比较,仅考虑降雨蒸发量的堆场盈亏水量计算结果偏大,未考虑沉降挤出水量的计算结果偏小,采用本文推荐的计算公式可得出较为科学合理的渗滤液产量。

Impacts of initial moisture content and consolidation character on leachate generation of wet phosphogypsum stack

While most phosphogypsum (PG) are disposed by stacking, there has been little research on leachate generation from PG stacks.This study analyzed the influence of various factors on the water inventory of a PG stack and established a water balance analysis model to evaluate the contribution of each factor.The consolidation characteristics of PG were determined through the 1D consolidation test.An integrated leachate computation formula was proposed.Leachate generation from each operational stage was calculated at four different initial moisture contents using three different computation formulas.The calculation results show that freshwater must be added to the PG stack to guarantee normal operation in the early operation stage.Leachate generation increased gradually over time.In each stage, the leachate generation differed significantly from the average of the entire calculation cycle.Leachate generation increased as initial moisture content decreased.The calculation results for each formula were compared.The formula including only rainfall and evaporation in calculations yielded more leachate than anticipated, while the formula that did not include consolidation water yielded less leachate than anticipated.The proposed formula provides a reasonable estimate of leachate generation from PG stacks.