Utilization of Demolition Waste for Treatment of Acid Mine Drainage and Immobilization of Heavy Metals Released from Copper Flotation Tailings

Abstract

In this study, the treatment of acid mine drainage (AMD) and immobilization of heavy metals released from CFT (copper flotation tailings) were investigated using strongly alkaline demolition waste (DW), collected from the urban renewal areas. Shake flask batch tests were conducted to assess the influence of time and different ratios of CFT/DW on the acidity and heavy metal release characteristics of the drainage water. During the tests, samples were collected from filtered leachates at regular intervals to monitor pH, SO42- and release of heavy metals. The results indicated that the pH increased from 2.21 (t=0) to 10.37 after 120 minutes of shaking in an orbital shaker. The highest SO42- release ([SO42-]=4558 mg L-1, t=0) was measured at 1:3 dose of CFT:DW application with 257 mg L-1 (pH=10.37) at the end of 120 minutes. The addition of DW almost completely reduced the release of heavy metals from CFT due to its high alkaline content. As a result, it was suggested that DW could effectively be used for the treatment of AMD and immobilization of heavy metals released from CFT.