金属钙离子对煤中含硫活性基团的阻化效果研究

Study of inhibition effect of Ca^(2+) on sulfur contained active groups in coal

为了揭示阻化剂抑制煤炭自燃的机理,提高阻化效果。采用Gaussian03软件包,对含CaCl_2阻化剂中的金属Ca^(2+)与煤中含S活性结构形成的配位体及分子前沿轨道、稳定化能、自然键轨道和净电荷布居、自然电子组态进行系统研究。结果表明,金属Ca^(2+)能够与煤中含S活性结构反应形成稳定化能变大,前沿轨道能级能隙差变小,形成二配体、三配体及四配体配合物。而且形成配合物后,含S活性结构对前沿轨道的贡献大大减少,同时轨道能级大幅增加,增加了煤中含S活性结构的稳定性,降低了煤的活性,使煤不易于氧发生反应,可有效预防煤炭自燃。

In order to study the mechanism of delaying coal spontaneous combustion through the inhibitor agent and improve inhibition effect, the chemical reactions between CaCh and coal have been studied. This research includes the study of ligand structure, formed by combination of Ca2＋ and sulfur （S） contained active structure of coal, molecular frontier orbital, stabilization energy, natural bond orbital, Mulliken population and charge transfer. All the calculations are performed with the Ganssian03 program. The calculation results indicate that bidentate, tridentate and quadridentate ligands can be formed through the chemical reaction between Caz＋ and S contained active groups in coal. During the generation of the complexes, stabilization energy becomes higher and the energy gap of frontier molecular orbital becomes lower, making a stable complex formed. After the formation of those complexes, the contribution of S contained active structure is greatly reduced in the molecular frontier orbital. The orbital energy level increases dramatically, improving the stability of the active structure and retarding oxidation reaction.