摘要
采用活性焦作为构造煤大分子网络的基质 ,将无机硫 (黄铁矿、硫酸亚铁 )混合于其上 ,形成模拟煤的环境 .利用程序升温热解 火焰光度检测器或质谱联用 (TPD FPD/MS)技术和X 射线吸收精细结构 (EXAFS)光谱对比研究了FeS2 、FeSO4在活性焦上及纯态下热分解过程中硫逸出的动态特征及结构变化 .结果表明 :担载于活性焦上FeSO4的分解主要发生在 2 0. 0℃～5 0. 0℃ ,而纯态FeSO4的分解温度范围为 4 5. 0℃～ 6 0 .0℃ ,说明活性焦的存在使其分解温度显著降低 ,且硫的逸出情况更为复杂 .黄铁矿与活性焦的物理混合并没有使FeS2 的分解温度降低 ,但对其分解程度有一定的影响 ,并与热解气氛密切相关 ;温度高于 4 0. 0℃后FeS2 分解的硫开始大量逸出 ,在 5 5.0℃左右基本失去结构中与铁配位的第 2层硫原子而形成FeS .
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 FeS_2 and FeSO_4 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 FeSO_4 impregnated onto AC mainly happened between 200℃ and 500℃, while the pure FeSO_4 decomposed at around 450℃～600℃. The comparison shows that the existence of AC lowered the decomposition temperature of FeSO_4, 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℃, the evolution of sulfur became remarkable. At around 550℃ the sulfur in the second sphere of Fe-S-S was lost, and the pyrolysis product FeS appeared simultaneously.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2005年第2期69-73,共5页
Environmental Science
基金
中国博士后科学基金项目 (2 0 0 40 3 5 0 2 3 )
