(中南大学 资源加工与生物工程学院，长沙 410083)
摘 要: 通过单矿物浮选实验、吸附量测定和分子动力学模拟分析了十二烷基三甲基氯化铵(DTAC)和四丁基氯化铵(TBAC)在铝土矿反浮中浮选行为和作用机理。结果表明，相比DTAC而言，TBAC可在更低的药剂浓度和更宽的pH范围下有效地分离高岭石和一水硬铝石。借助分子动力学模拟构建季铵盐分子在高岭石(001)面最优吸附构型，表明TBAC具有大头基短烃链的结构特点，使其在高岭石表面的接触面为DTAC的3.4倍，在高岭石表面产生更多的CH？？？O氢键，吸附能更低。理论计算和浮选实验、吸附量测定结果相互一致，可为探索新型铝土矿反浮选药剂提供理论基础。
关键字: 季铵盐；分子结构；动力学模拟；反浮选
（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
