烷基吗啉在氯化钠和氯化钾表面的吸附

摘要

The adsorption of alkylmorpholine (DMP) on NaCl and KC1 crystals was studied with the density functional theory (GGA-PW91) using computer simulation, where NaCl(100) with F color center and KCK100) with O2- defect. The charges of ions on NaCl (100) are changed to positive by F color center, while the charges of ions on KC1(100) are changed to negative by O2- . The adsorption energy of DMP on Na-top is -157. 00 Kj · Mol-1 and that on KCK100) with O2 is -59. 14 Kj · Mol-1. Therefore, DMP can be adsorbed on both NaCl and KC1, and the interaction between NaCl and DMP is stronger. The flotation experiments on the overflow potash ore containing alkylmorpholine indicate that the flotation recovery for NaCl is high, while the recovery of KC1 is low. This result reflects different adsorption characteristics of DMP on surfaces of NaCl and KC1, which corroborates the result of computer simulation.%采用密度泛函理论(DFT)的PW91方法,研究了十二烷基吗啉(DMP)分子在带缺陷的NaCl(100)和KCl(100)上的吸附情况.缺陷引入后晶体表面离子电荷发生较大变化,使得NaCl(100)表现出正电性,而KCl(100)则表现出负电性.DMP在NaCl(100)的Na顶位发生吸附,吸附能约为-157.00 kJ·mool-1 ;DMP在KCl(100)的K顶位发生吸附,吸附能约为-59.14 kJ·mol-1.因此,氯化钠和氯化钾都对DMP有吸附作用,而氯化钠对DMP的吸附强于氯化钾.含有烷基吗啉的溢流细晶的浮选结果表明:烷基吗啉对氯化钠有很高的浮选回收率,而对氯化钾的浮选回收率则较低.浮选结果很好地印证了模拟计算所得出的烷基吗啉在氯化钠和氯化钾表面的不同吸附特征.