盱眙、明光、临泽坡缕石的八面体阳离子占位及对其性能的影响

坡缕石是一种21型链层状结构含水富镁铝硅酸盐矿物，具有重要的资源和材料属性。不同成因、产状坡缕石八面体中类质同象替代有很大差别，而八面体类质同象替代对坡缕石性能的影响未见研究报道。本文以中国最具代表性的安徽明光、江苏盱眙、甘肃临泽坡缕石为研究对象，研究了三种坡缕石的Al、Mg、Fe含量及在八面体中的占位，并探讨了八面体的Al、Mg、Fe占位对坡缕石中水的种类和含量、表面电位和酸位以及对Pb2+、Cd2+吸附性能的影响。结果表明：明光坡缕石相对富镁，八面体主要被Mg2+占据，具有三八面体特征；盱眙、临泽坡缕石相对富铝、铁，八面体主要被Al3+占据，表现出更多的二八面体特征。盱眙坡缕石由于M1位置空位较多，结构水含量较低；坡缕石类质同象替代对Zeta电位影响不大；具有二八面体特征的盱眙、临泽坡缕石由于八面体中Al含量较高，酸位较多，催化性能较好。在重金属吸附实验中，明光坡缕石对Cd2+的吸附效果最好，盱眙坡缕石对Pb2+的吸附效果最好，临泽坡缕石吸附性能较差。本文可为坡缕石的改性和应用提供指导和参考。

Octahedral cation occupancy of Xuyi, Mingguang and Linze palygorskites and its effect on properties

Palygorskite is a 21 type chain layered structure hydrated magnesium aluminosilicate mineral with important resource and material attributes. Althoughthe isomorphic substitution in the octahedron of palygorskite varies depending on its genesis and occurrence, the impact of this substitution on the properties of palygorskite remains unexplored. In this study, we focused on three representative palygorskites samples obtained from Anhui Mingguang, Jiangsu Xuyi, and Gansu Linze in China. The study investigated the content and octahedral occupation of Al, Mg, and Fe inthese palygorskites, and examined how these factors influenced the types and contents of water, surface potential, acid sites, as well as the adsorption capacity for Pb2+and Cd2+ ions in palygorskite.The results showed that Mingguang palygorskite exhibited a relatively high magne siumcontent, while Xuyi and Linze palygorskites were richer in aluminum and iron. The octahedral sitesinMingguang palygorskite weremainly occupied by Mg2+, showing three octahedron characteristics. Xuyi palygorskite exhibited a higher proportion of Al3+ in the octahedral sites,indicating more two octahedron characteristics. Similarly, Linze palygorskite also displayed two octahedron characteristics, with acation occupation pattern similar to that of Xuyi palygorskite. Due to alarge number of vacancies at the M1 site, Xuyi palygorskite exhibited a lower structural water content.Isomorphic substitution inpalygorskite had minimal impact on the Zeta potential. Xuyi and Linze palygorskites, with two octahedron characteristics,demonstrated higher Al content in the octahedral sites, more acid sites, and better catalytic performance. In the heavy metal adsorption experiment, Mingguang palygorskite displayed the highestadsorption capacity for Cd2+, while Xuyi palygorskite exhibited the highest adsorption capacity for Pb2+. Linze palygorskite, however, demonstrated poor adsorption performance.The findings of this study provide guidance and references for the modification and application of palygorskite.