Key Laboratory of High-temperature and High-pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China.
University of Chinese Academy of Sciences, Beijing, 100039, China.
Environ Sci Pollut Res Int. 2017 Sep;24(27):21710-21720. doi: 10.1007/s11356-017-9804-9. Epub 2017 Jul 31.
We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.
我们研究了不同酸度和温度下模拟酸雨对黄铁矿电化学腐蚀行为的影响。循环伏安法、极化曲线和电化学阻抗谱结果表明，黄铁矿在不同的模拟酸雨条件下具有相同的电化学相互作用机制，无论是酸雨酸度较强还是环境温度较高，都能加速黄铁矿的腐蚀。与 25°C 时 pH 值为 5.6 的酸雨相比，当酸雨 pH 值降至 3.6 时，黄铁矿风化的瞬时效率达到 104.29%，当环境温度升高至 45°C 时，达到 125.31%。在其他条件不变的情况下，酸度的增加会显著降低电荷转移电阻，而温度的升高会显著降低钝化膜电阻。酸雨总是导致较低的酸度矿山排水，较强的酸度或高温会导致严重的酸性排水。纬度、海拔和季节等自然参数对黄铁矿风化有很大的影响，因为温度是一个重要的影响因素。这些实验结果对评估和管理受酸雨影响地区的硫化物矿物酸性排水具有直接意义。
