EXPERIMENTAL STUDY ON THE TREATMENT OF COAL MINE WASTEWATER WITH LIME SOFTENING PROCESS
ZHANG Ke-bing;GAO Jie;ZHENG Peng-sheng;Resources and Environment Department of Huainan Coal Mining Group Corporation Ltd;CCTEG Hangzhou Environmental Research Institute;
Ac cording to the negative hardness characteristics of Xinzhuangzi Coal Mine drainage, the lime softening experiment was carried out to inspect the variation characteristics of total hardness, total alkalinity、p H and conductivity. The results showed that the total hardness of effluent was reduced from 260mg.L-1to 144mg.L-1with its removal rate of 44.6% at the optimal dosage 150mg.L-1. No sediment was formed when the effluent boiled. This condition can met the reuse requirements of coal mine wastewater. The total alkalinity was gradually reduced by lime dosing, while the p H always rose, the conductivity fell first and then rose. The medicament cost of lime softening process was estimated to be 0.214 Yuan/m3. In summary, lime softening should be preferred for treating coal mine drainage of Xinzhuangzi Coal Mine.