(1. 太原理工大學(xué) 礦業(yè)工程學(xué)院，太原 030024；
2. 太原理工大學(xué) 煤科學(xué)與技術(shù)教育部和山西省重點(diǎn)實(shí)驗(yàn)室，太原 030024)
摘 要: 采用分子動力學(xué)模擬方法，研究周期性水環(huán)境下十二胺在石英及磁鐵礦界面上的吸附過程。考慮到十二胺的水解電離平衡以及礦物表面荷電機(jī)理，建立弱酸、中性以及強(qiáng)堿性3種條件下十二胺與石英及磁鐵礦的吸附模型。采用微量熱儀測量十二胺在石英及磁鐵礦表面吸附過程中的吸附熱。模擬結(jié)果表明：中性環(huán)境有利于十二胺在礦物表面的吸附；弱酸性條件下十二胺不能吸附于磁鐵礦表面；強(qiáng)堿性環(huán)境下十二胺與石英及磁鐵礦的相互作用很弱。十二胺與石英作用的吸附焓大于十二胺與磁鐵礦的，十二胺更易于吸附在石英表面，且十二胺在礦物表面的吸附為物理吸附。分子動力學(xué)模擬與吸附熱試驗(yàn)從分子力學(xué)及熱力學(xué)層面上揭示了浮選過程中十二胺對石英及磁鐵礦選擇性的差異的原因。
關(guān)鍵字: 分子動力學(xué)模擬；十二胺；石英；磁鐵礦；吸附熱
（1. College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
2. Key Laboratory of Coal Science and Technology of Ministry of Education and Shanxi Province,
Taiyuan University of Technology, Taiyuan 030024, China）
Abstract:The adsorption process of dodecylamine (DDA) on quartz and magnetite surfaces at a molecular level was studied by molecular dynamics (MD) simulations method. In the consideration of hydrolysis ionization equilibrium and surface charge mechanism of DDA, a model close to the realistic flotation system was established to simulate the adsorption behavior under the weak acid, neutral and strong alkali conditions. The adsorption heat in the adsorption process of DDA on quartz and magnetite surface was measured by micro calorimeter. The results indicate that the optimum condition for DDA adsorption on mineral surface is at neutral environment; it is difficult for DDA adsorption on magnetite at weak acid environment; and the interaction of DDA and mineral is weak under strong alkali condition. The interaction energy of DDA and quartz is higher than that of DDA and magnetite. DDA is preferred to adsorb on the surface of quartz, and the adsorption process is physical adsorption. The selectivity phenomenon in molecular mechanics and thermodynamics level was explained by MD simulation and microcalorimetry measurements experiment.
Key words: molecular dynamics simulation; dodecylamine; quartz; magnetite; adsorption heat
