钛铁矿与捕收剂吸附过程中的匹配机制及界面作用

The adsorption between ilmenite and collectors is a critical interfacial phenomenon in ilmenite flotation. High efficiency will be obtained for ilmenite flotation, if the spatial structure and interfacial characteristics during adsorption of ilmenite and collectors are explored deeply. Molecular dynamics simulation, adsorption kinetics, adsorption thermodynamics, AFM and XPS are employed to investigate the adsorption. The molecular dynamics simulation is used as the microscopic molecular aspect to reveal preferential adsorption sites, interaction energy and also spatial structure matching mechanism for collector and ilmenite adsorption process. Interaction effects are analyzed between titanium site and iron site in adsorption process. Kinetic characteristics is analyzed by quartz crystal microbalance with dissipation and ultraviolet-visible spectrophotometer. We also used microcalorimetric test technology on the determination for adsorption thermodynamics function value of ilmenite and collectors. Interaction force in adsorption process is analyzed by AFM and EDLVO theory. And adsorption layer structure is tested by XPS. Therefore, interfacial adsorption characteristics between ilmenite and collectors are studied on multi-scale and multi-angles in this project, it is helpful to have a thorough understanding of ilmenite flotation features, provide theoretical support for the design of high efficient collectors, promote the development of new technology of flotation.

钛铁矿与捕收剂的吸附作用是钛铁矿浮选过程中重要的界面现象，深入探究捕收剂在钛铁矿表面发生有效吸附时的空间结构和界面性质，对钛铁矿的高效浮选具有重要的指导意义。本项目拟通过分子动力学模拟、吸附动力学、吸附热力学、AFM和XPS研究捕收剂与钛铁矿吸附的相互作用。采用分子动力学模拟，从微观层面揭示捕收剂与钛铁矿吸附过程中的优先吸附位点，相互作用能以及空间结构匹配机制，分析钛位点和铁位点对吸附作用的相互影响；利用石英晶体微天平和紫外-可见光分光光度计，探究宏观吸附过程的动力学特征；采用微量热测定钛铁矿与捕收剂吸附的热力学函数值；采用AFM和EDLVO理论分析吸附过程中的相互作用力；利用XPS测试吸附层厚度。从多角度多尺度研究钛铁矿与捕收剂吸附的界面性质，深入探究钛铁矿的浮选特性，为高效捕收剂的设计提供理论支撑，推动浮选新技术的发展。

钛铁矿与捕收剂的吸附作用是钛铁矿浮选过程中重要的界面现象，深入探究捕收剂在钛铁矿表面固液界面性质，对钛铁矿的高效浮选具有重要的指导意义。本项目通过羟胺法合成长链烷基羟肟酸钠，包括油酸羟肟酸钠（NaOHA）和反式-2-壬烯酸羟肟酸钠（xin2），通过分子动力学模拟、K100、QCM-D、AFM、XPS和FT-IR等研究了捕收剂与钛铁矿吸附的相互作用。. 结果表明：钛铁矿样品接近于非极性表面，水化膜厚度随钛铁矿粒级减少而增大，长链烷基羟肟酸钠是钛铁矿浮选的高效捕收剂，对纯矿物和实际钛铁矿的浮选，均具有较好的捕收性和选择性；在捕收剂用量100 mg/L时，NaOL、NaOHA和xin2对钛铁矿纯矿物的回收率分别为80.46%，78.49%，89.05%，NaOL、NaOHA和xin2对镁橄榄石纯矿物的回收率分别为80.03%，43.64%，10.00%；当xin2捕收剂的用量为1000g/t时，钛铁矿实际矿物浮选的精矿产率为60.33%，回收率达86.62%。采用分子动力学模拟，对钛铁矿101面和001面的Fe位点和Ti位点与捕收剂吸附作用进行研究，钛铁矿中的001解离面与捕收剂的作用能力强于101解离面，羟肟酸捕收剂与钛铁矿中Ti位点的吸附能力大于Fe位点， NaOHA与钛铁矿001面Ti位点的吸附作用能为-2913.88 kcal/mol，与001面的Fe位点的吸附作用能为-2017.58 kcal/mol，吸附机理包括静电吸附、氢键吸附、特性吸附、化学吸附和疏水吸附；油酸羟肟酸钠捕收剂在钛铁矿表面的吸附为多层吸附，分析了吸附膜厚度，捕收剂中的O、N原子提供的孤电子对吸附在钛铁矿表面的Fe及Ti活性位点上，作用能较强。项目开发了长链烷基羟肟酸钠，具有较好的应用前景，多角度多尺度研究了与钛铁矿吸附的界面性质，深入探究钛铁矿的浮选特性，为高效捕收剂的设计提供理论支撑和技术原型，推动浮选新技术的发展。