木质素系和萘系分散剂在煤水界面的吸附性能

研究了两种木质素类分散剂SL(木质素磺酸钠)和MSSL(改性磺化碱木质素钠盐)和一种萘系分散剂(FDN)在大同煤表面的吸附量和动力学, 结果表明, SL和MSSL在煤表面的吸附量远比FDN的大, 但是拟合所得的Langmuir平衡常数K和吸附速率常数ka都比FDN的小, 这表明SL和MSSL在煤表面的吸附能力比FDN略差, 吸附速率较慢. 采用IR和XPS研究了煤表面分散剂吸附层的结果表明, 吸附了SL和MSSL的煤表面具有明显的“红移”现象, 并且SL和MSSL在煤表面的吸附层厚度分别为7.22和4.61 nm, 而FDN的吸附层厚度较小, 为2.11 nm. 分析认为, SL和MSSL在煤表面的吸附以氢键力为主, 吸附量较大, 吸附层较厚, 在煤表面呈多点式吸附; FDN主要以π电子极化吸附在煤表面呈卧式吸附, 吸附强度较大, 吸附层较薄.

Adsorption Property of Lignin and Naphthalene Dispersants on Coal-water Interface

The adsorption amount and kinetics of two lignin series dispersants(SL and MSSL) and one naphthalene dispersant(FDN) on Datong coal surface were studied, the results show that the adsorbed amounts of SL and MSSL on coal surface were far more than that of FDN. However, the fitted parameters of Langmuir equilibrium constant K and adsorption rate constant ka of SL and MSSL were less than that of FDN, which indicat that the adsorption ability of SL and MSSL on coal surface was inferior to that of FDN, and the adsorption rate of SL and MSSL on coal surface was lower than that of FDN. The adsorption layer of dispersant on coal surface was studied by using IR and XPS methods, and the results show that the coal with adsorbed SL and MSSL have evident “red shift” phenomenon. Moreover, the adsorbed layer thickness of SL and MSSL on coal surface was 7.22 and 4.61 nm respectively, however, that of FDN was thinner, only 2.11 nm. It is generalized that the hydrogen bond is the main adsorption force of SL and MSSL on coal surface, the adsorbed amount is rather large, the adsorbed layer is rather thick, and the multi-point adsorption on coal surface is the main form. The main form of FDN adsorbed on coal surface is horizontal adsorption by π-electron polarized adsorption, and the adsorbed strength is rather large, but the adsorbed layer is rather thin.