Micro-electrolysis And Precipitation Of The Acidic Underground Mine Water Research

The technical conditions of treating acid mine drainage by chemistry precipitation and micro electrolysis methods as well a- mechanism of micro electrolysis were studied in this paper. And feasible treating technology were given in this paper.Heavy metals in the drainage were efficiently removed in the coagulation precipitation and neutralizing precipitation process, the rate of removal reached 99%.The treated water quality met the demand of water discharge set by the government except the concentration of Sb.The optimization of treatment were: pH6~7; PAC=30mg/L.By comparing the coagulation precipitation and neutralizing precipitation, it was found that the former process could reduce the dosage of lime and quicken the velocity of the sedimentation.The concentration of Sb in the water could be efficiently removed in the micro electrolysis process. The micro electrolysis reactor was filled by activated carbon and cast iron. By observing the results of micro electrolysis static treatment and neutralizing precipitation treatment ,the sequence of the treatment was confirmed: the former micro electrolysis s treatment, the later is neutralizing precipitation.In the micro electrolysis dynamic process, several primary factors influencing the removal rate of the heavy metals were discussed: the pH of the inflow, the retention timeN the adsorption volume in alkali > the deposit timeN the stirring intensity and stirring time. Through the results of orthogonal experiments,it was clear that in the range of the selective factors, the most primary factor influencing the removal rate of the heavy metals was the retention time,the secondary factor is the adsorption volume in alkali, the least was the deposit time. Optimization lied in the former two factors. The optimization of treatment were: the retention time20min, the dosage in alkali2ml. the deposit time30 min. The treated water quality met the demand of water discharge of the government and could be used in the flotation process. It was shown that the treated water has no adverse effect. The flotation index of the treated water was similar to that of the pure water.In addition, the mechanism of micro electrolysis treating technology was discussed in details.