Utilization of pit-water reources in Huanbei coal mine area

Almost all the water supplies come from groundwater in Huaibei coal mine area. In the northern area, surface soil are thin and there are some outcrop of Paleozoic karstified lime strata with plentiful groundwater, and the chief water sources in the southern part are the upper porous aquifers. The total drained pits' water is about 9.0 X 10(4) m(3)/d. 11 drained water purifying plants have been set up, which adopted 3 types of treating techniques: chemical treating, absorbing of active carbon and electrodialysis, total purifying percentage is 55.5% of drained water. The purified water is used for production and life consumption. The combination of mine drainage and water supply is used to fall the high hydraulic pressures from the aquifers near coal seams and to increase usable water resources. Its application has evidently reduced quantities form the porous aquifers, and stopped groundwater level's sharp drawdown.