(中南大學 資源加工與生物工程學院，長沙 410083)
摘 要: 通過單礦物浮選實驗、吸附量測定和分子動力學模擬分析了十二烷基三甲基氯化銨(DTAC)和四丁基氯化銨(TBAC)在鋁土礦反浮中浮選行為和作用機理。結果表明，相比DTAC而言，TBAC可在更低的藥劑濃度和更寬的pH范圍下有效地分離高嶺石和一水硬鋁石。借助分子動力學模擬構建季銨鹽分子在高嶺石(001)面最優(yōu)吸附構型，表明TBAC具有大頭基短烴鏈的結構特點，使其在高嶺石表面的接觸面為DTAC的3.4倍，在高嶺石表面產(chǎn)生更多的CH？？？O氫鍵，吸附能更低。理論計算和浮選實驗、吸附量測定結果相互一致，可為探索新型鋁土礦反浮選藥劑提供理論基礎。
關鍵字: 季銨鹽；分子結構；動力學模擬；反浮選
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:The flotation behavior and interaction mechanism of dodecyl trimethyl ammonium chloride (DTAC) and tetrabutylammonium chloride (TBAC) with bauxite in the process of reverse flotation desilication were studied using single mineral flotation test, the adsoption of reagents and molecular dynamics simulation. The results show that compared with DTAC, TBAC can separate kaolinite and diaspore effectively at lower concentration and wider pH range. Based on the molecular dynamics simulation, the adsorption models of TBAC and DTAC on kaolinite (001) plane were constructed and optimized. Owing to the bigger head group and shorter hydrophobic group of TBAC, the contact area of TBAC on kaolinite (001) plane is larger and the CH？？？O hydrogen bond is stronger than DTAC. In addition, higher adsorption energy will be released when TBAC is adsorbed on kaolinte surface. The theoretical computations match remarkably well with the experimental results. Therefore, it can provide a theoretical basis for exploring new reagent in reverse flotation desilication for bauxite.
Key words: quaternary ammonium salt; molecular structure; dynamics simulation; reverse flotation
