德兴铜矿不同年份废石产酸规律研究

矿山选矿废石、尾矿在长期堆积过程中氧化产生的酸性废水会对环境造成严重危害.实验选取德兴铜矿1、5、10和20年废石进行产酸规律研究,静态评价结果显示,4种废石均有产酸潜势,且除1年废石以外均已产酸.为期9个月的动态评价结果表明,4个年份的废石pH均与电导率呈显著负相关,检出离子主要为氟化物、Cu2+、Zn2+、SO2-4、Fe3+.1年废石在整个实验进行中并未产酸,5、10年废石产酸稳定,20年废石产酸缓慢,可推断废石的产酸过程为:不产酸-高速产酸-稳定产酸-产酸速率下降.

Acid production rules of waste rocks in different years from Dexing copper mine

Waste rocks (WR) and tailings containing metal sulfides at mine sites undergo oxidation during their storage, which produces acidic and metallic drainage (AMD) and causes serious environmental damages. The objective of the present experiment was to evaluate the acid generation potentials of waste rocks from Dexing Copper Mine, which had been stored for 1, 5, 10, and 20 years, respectively. Static test results showed that the waste rocks of 4 different ages had acid generation potentials. Apart from the fresh waste rock with 1 year old, all other waste rocks generated acid. The results of 9-month kinetic test showed that the pH of waste rocks of the four different age categories was significantly negatively correlated with leachate conductivity. The main solutes in the leachates were F, Cu²⁺, Zn²⁺, SO₄^2- and Fe³⁺. In the kinetic test, the 1-year waste rock did not yet produce acid during the experimental period, but, 5- and 10-year old waste rocks produced acid persistently. The acid production rate of the 20-year old waste rocks declined. The acid production capacity was in the process of non-production-rapid production-stable production-declined production.