关键词: 铜矿废石, 动态淋溶, 产酸, 重金属, 释放规律

Abstract: Metal mine waste rock exposed to the natural environment is easy to produce acidic pollutants and release heavy metal ions,causing serious pollution to the surrounding environment. In view of the long-term nature of its pollution,it is necessary to study the acid production law of waste rock and the behavior of releasing heavy metals ions. A copper mine waste rock in Jiangxi Province was taken as the object,and the influence of factors such as the pH value of the leaching solution,the particle size of the waste rock,and the intensity of leaching (drench solution flow rate) on the acid production and the release of heavy metals ions was investigated through the dynamic leaching test. The results showed that the pH value of the drenching solution was negatively correlated with the amount of SO2- 4 production and the release of Cu and Pb,and the lower the pH value of the drenching solution was,the greater the cumulative release of SO2- 4 ,Cu and Pb. In contrast,Zn showed a different trend, and its cumulative release was higher at a drenching solution pH of 5 than that at a drenching solution pH of 3,which indicated that Zn was more likely to be released from the drenching solution in a weakly acidic environment. The smaller the particle size of waste rock,the more favorable to waste rock acid production and release of heavy metals ions,fine particle size waste rock leaching system in the SO2- 4 ,Cu,Pb,Zn cumulative release of up to the coarse particle size waste rock. The drench solution flow rate was positively correlated with SO2- 4 production and heavy metal ions release,and the cumulative releases of SO2- 4 ,Cu,Pb and Zn could reach 1 389. 55 mg/ kg,310. 18 μg/ kg,413. 18 μg/ kg and 281. 62 μg/ kg,respectively,in the system of drenching with a high drench solution flow rate (1. 02 mL/ min),a low initial pH of drench solution (3),and a fine-sized waste rock (0. 15~0. 25 mm). The results of the study can provide guidance for the behavior of acid production and release of heavy metals ions from waste rock of the similar non-ferrous metal mines and pollution management.

Key words: copper mine waste rock,dynamic leaching,acid production,heavy metals,leaching law