Heavy Metal Leaching Experiments With Mining Rocks In Xinqiao Pyrite Mine

Through leaching experiments with the mining rocks in Xinqiao pyrite mine, the acid-producing potential, the changes of pH values, the changes of SO₄^2- concentration and leaching regularities of heavy metals, such as Fe, Cu, Pb, Zn, Cd, in leaching water of the mining rocks with different particle sizes and the sterilization samples were studied. The results show that, in the leaching process with the water whose pH value was close to natural water's, the mining rocks produced acid. It is also found that, the changing tendency of the pH values was in accord with that of the SO₄^2- concentration in leaching water, excluding the effect of acid-producing potential of mining rocks on pH value. Otherwise, the leaching amounts of the heavy metal elements changed in the leaching process along with time, and were affected by several factors such as particle sizes of mining rocks and pH value, and there was correlativity between these heavy metal elements. The microorganism experimental research was done by leaching the mining rock samples which were sterilized, and was compared with the mining rock samples not sterilized. It indicates that microorganism has an influence on the change of pH value and leaching regularities of heavy metals.