Abstract: With the waste coal gangues of an abandoned coalmine in Shaoguan as the main raw materials, the modified coal gangues A, B, C were prepared. These three modified gangues together with the unmodified gangues are used to make laboratory tests for removal of sulfide from the wastewater of Fankou Lead-zinc Concentrator. The results showed that the modified gangue A has a higher ability to remove the sulfide and the appropriate conditions for sulfide removal include the room temperature, the original pH value of wastewater, the gangue dosage of 2.0 g/L, stirring speed at 300 r/min and reaction time for 60 min. According to the results of laboratory tests, modified coal gangue A was adopted into the pilot plant tests to remove sulfide from the beneficiation wastewater in Fankou Lead-zinc Mine. By this method, the removal rate of sulfide reached above 87.5%, and the concentration of sulfide dropped to 0.42 mg/L below, which meet the national and Guangdong Provincial discharging standard.

Key words: Modified gangue, Lead-zinc mineral processing wastewater, Removal of sulfide