【摘要】 萤石（CaF₂）作为国家战略性矿产资源，其高效回收面临重大挑战：一方面与方解石等钙质矿物紧密共生，另一方面浮选体系中金属离子(Ca²⁺、 Ba²⁺、 Fe³⁺)的干扰导致选择性分离效率低下。本研究采用溶液化学计算、 zeta电位分析、红外光谱分析（FTIR）和X射线光电子能谱（XPS）分析技术，系统揭示金属离子调控辛基异羟肟酸（OHA）在萤石表面吸附的微观机制。通过溶液化学计算与zeta电位分析，表明金属离子在一定的pH值下金属阳离子优势组分通过压缩萤石颗粒表面双电子层的方式改变萤石表面zeta电位，导致矿物表面zeta电位负值降低，萤石表面电位调控使OHA吸附量提升。FTIR结果表明，经OHA处理后的萤石谱图中多处出现了OHA官能团，说明OHA在萤石表面发生化学吸附。经金属离子和OHA处理的萤石谱图中，出现了—CH₃、—CH₂—、 CO、 C—N、 C—C—C、 C—O、 N—O吸收峰，且吸收峰有所增强。XPS深度分析揭示，金属离子作用萤石后吸附OHA的含量都明显高于未经金属离子作用的萤石吸附OHA的含量。经金属离子和OHA处理萤石后，Ca（2p）的结合能偏移量变大，Ba、 Fe可取代表面Ca晶格位点，N（1s）峰强度增加，并形成Me—O—N新型键合方式，结合zeta电位、 FTIR以及XPS分析，金属离子对萤石与OHA吸附效能序列：Fe³⁺>Ba²⁺>(Ca²⁺/Ba²⁺/Fe³⁺)≥(Ca²⁺/Ba²⁺)≥(Ca²⁺/Fe³⁺)>Ca²⁺。该研究建立的“金属离子—界面—药剂”三元作用模型，为复杂水质条件下萤石高效浮选提供了理论支撑，所发现的晶格取代-化学吸附协同机制对新型浮选药剂设计具有重要参考价值。更多还原

【Abstract】 As a national strategic mineral resource, the efficient recovery of fluorite（CaF₂） faces major challenges: on the one hand, it is closely associated with calcareous minerals such as calcite; on the other hand, the interference of metal ions(Ca²⁺, Ba²⁺, Fe³⁺) in the flotation system leads to low selective separation efficiency. In this study, solution chemical calculation, zeta potential analysis, infrared spectroscopy（FT-IR）, and X-ray photoelectron spectroscopy（XPS） analysis techniques were used to systematically reveal the microscopic mechanism of metal ions regulating the adsorption of octyl hydroxamic acid（OHA） on fluorite surface. It shows that the dominant components of metal cations change the surface zeta potential by compressing the double electron layer on the surface of fluorite under a certain range of pH values, resulting in a decrease in the negative zeta potential of the mineral surface, and the surface potential regulation of fluorite increases the adsorption capacity of OHA. FTIR results showed that OHA tube energy groups appeared in many places in the fluorite spectrum after OHA treatment, indicating that OHA was chemically adsorbed on the surface of fluorite. The absorption peaks of —CH₃, —CH₂—, CO, C—N, C—C—C, C—O, and N—O appeared in the spectra of fluorite treated with metal ions and OHA, and the absorption peaks were enhanced. XPS depth analysis revealed that the content of OHA adsorbed by fluorite after metal ions was significantly higher than that of OHA adsorbed by fluorite without metal ions. After the treatment of fluorite with metal ions and OHA, the binding energy offset of Ca（2p） increases. Ba and Fe can replace the surface Ca lattice site, and the intensity of the N（1s） peak increases, and a new bonding mode of Me—O—N is formed. Combined with zeta potential, FTIR and XPS analysis, the adsorption efficiency sequence of metal ions on fluorite and OHA is: Fe³⁺>Ba²⁺>(Ca²⁺/Ba³⁺/Fe³⁺)≥(Ca²⁺/Ba²⁺)≥(Ca²⁺/Fe³⁺)>Ca²⁺. The ternary interaction model of “metal ion-interface-reagent” established in this study provides theoretical support for the efficient flotation of fluorite under complex water quality conditions. The synergistic mechanism of lattice substitution-chemical adsorption found in this study points out the direction for the design of new flotation reagents.更多还原