Study On Treating And Recycling Of Wastewater From Lead-zinc Mineral Processing

The wastewater produced from lead-zinc mineral processing contained a lot of flotation reagents and heavy metal ions. so the study on how to remove these harmful material in the wastewater effectively and reuse wastewater, not only can protect the environment, but also improve the utilization ratio of water resource.The study on removing flotation reagents and heavy metal ion in the wastewater using the method of coagulating sedimentation, chemical oxidation and adsorption, the dosage of reagents condition and the effect of pH has been investigated.The result of dosage tests showed that the method of coagulating sedimentation can remove flotation reagents and Pb2+effectively, the removal rate of four reagents is in the order of Pb2+> diethyl-amino-xanthate>butylxanthate> sodium humate, the removal rate of butylxanthate and diethyl-amino-xanthate can above90%by the method of chemical oxidation, and the rate of sodium humate is only15%, the method of adsorption can remove Pb2+, butylxanthate and diethyl-amino-xanthate effectively, but to sodium humate the result is not well. The result of pH tests showed that pH has little influence on the antioxidant.when the pH is acid and alkali, the removal efficiency of coagulant and adsorbent is very poor, only in the the right pH range the result is effect.On the other hand, treating industrial wastewater by the methods of coagulating sedimentation, chemical oxidation and adsorption were investigated. The results indicated that coagulating sedimentation method can remove the heavy metal ion in the wastewater effectively, but the reult of the flotation reagents is poor. After treating coagulating sedimentation, the activated carbon is adopted to adsorb the flotation reagents in wastewater, and the result indicated that adsorption method can remove flotation reagents effectively.The flotation results showed that the effect of flotation using the treated water, which is cleaned by the method of coagulating sedimentation-activated carbon adsorption, is almost the same as using fresh water,so the treated wastewater can be used in the process of flotation.