Xu Long, Ni Jin-ren
Department of Environmental Engineering, Peking University, Beijing 100871, China.
Huan Jing Ke Xue. 2005 Mar;26(2):69-73.
An activated charcoal (AC) was used to simulate coal-like environment, and the inorganic sulfur (pyrite or ferrous sulfate) was mixed with it in some ways. The dynamic characteristics and structure changes of FeS2 and FeSO4 with and without AC during pyrolysis, were investigated by temperature-programmed decomposition-flame photometric detector or mass spectrometer (TPD-FPD/ MS) and extended X-ray absorption fine Structure (EXAFS) spectroscopy. It is found that the decomposition of FeSO4 impregnated onto AC mainly happened between 200 degrees C and 500 degrees C , while the pure FeSO4 decomposed at around 450 degrees C - 600 degrees C. The comparison shows that the existence of AC lowered the decomposition temperature of FeSO4, and made the emission of sulfur more complex as well. However, the decomposition temperature of pyrite wasn't varied by the physical mixing with AC. Furthermore, the decomposition degree of pyrite depended on the existence of AC and the pyrolysis atmosphere used. Above 400 degrees C, the evolution of sulfur became remarkable. At around 550 degrees C the sulfur in the second sphere of Fe-S-S was lost, and the pyrolysis product FeS appeared simultaneously.
使用活性炭（AC）模拟煤样环境，并以某种方式将无机硫（黄铁矿或硫酸亚铁）与之混合。采用程序升温分解-火焰光度检测器或质谱仪（TPD-FPD/MS）以及扩展X射线吸收精细结构（EXAFS）光谱，研究了有无AC存在时FeS₂和FeSO₄在热解过程中的动态特性和结构变化。结果发现，负载在AC上的FeSO₄的分解主要发生在200℃至500℃之间，而纯FeSO₄在450℃至600℃左右分解。对比表明，AC的存在降低了FeSO₄的分解温度，同时也使硫的释放更加复杂。然而，黄铁矿与AC物理混合后其分解温度并未改变。此外，黄铁矿的分解程度取决于AC的存在以及所采用的热解气氛。在400℃以上，硫的析出变得明显。在约550℃时，Fe-S-S第二配位层中的硫损失，同时热解产物FeS出现。
