黄铁矿氧化的原位衰减全反射红外光谱表征

黄铁矿是自然界普遍存在的一种矿物，容易发生氧化反应，是酸性矿山废水(AMD)的主要来源。研究黄铁矿氧化有助于揭示其产生污染的机制。通过黄铁矿氧化生成硫酸，硫酸再与黄铁矿中所含碳酸盐(钙)反应生成二氧化碳这一设计实验，实现了黄铁矿在大气环境和水环境中氧化的原位衰减全反射红外光谱表征。通过对反应生成的CO₂进行原位表征，发现黄铁矿在空气和水中均存在明显的氧化作用，二者的氧化速率随时间而下降，差别在于，黄铁矿在水环境中的氧化速率下降较之在大气中显著，表明黄铁矿在水中的氧化较之在大气中要慢。在衰减全反射测量中，2 350 cm-1处表征CO₂的双吸收峰的选择性好，并可实现原位分析。

Characterization of Oxidation on Pyrite by In Situ Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy

Pyrite is one of common natural minerals in the environment,which is easily oxidated and is the main source of acidity mine drainage(AMD).The study on the oxidation of pyrite is helpful to comprehend the mechanism of its pollution.In the present paper,the oxidation of pyrite under the condition of air and water was respectively investigated by the attenuated total reflection-Fourier transform infrared spectroscopy(ATR-FTIR) through the designing experiment on the formation of carbon dioxide by the reaction of carbonate in pyrite with sulfuric acid formed by the oxidation of pyrite.The CO2 measurement by in situ ATR indicated that the oxidation rate of pyrite both in the air and in water both reduced by time and the latter reduced more obviously than the former,which indicates that the oxidation rate of pyrite in water is slower than that in the air.In the ATR measurement,the double absorption peaks at 2 350 cm-1 that indicates CO2 have high selectivity,and permits the in situ analysis.