类质同象置换对磁铁矿表面反应性的制约机制

Constraint Mechanism of Isomorphous Substitution on the Surface Reactivity of Magnetite

铁(氢)氧化物矿物对环境物质的地球化学行为有着重要的制约作用。相比于其他铁氧化物,磁铁矿具有一些独特的结构特征与表面性质,而赋予其良好的氧化还原活性。天然磁铁矿结构中广泛存在类质同象置换,探讨类质同象置换对磁铁矿表面反应的制约机制,有助于深刻理解磁铁矿族矿物在环境自净化过程中的作用机制。本文介绍了典型置换离子在磁铁矿结构中的赋存状态,及其对磁铁矿物化性质影响,重点阐述类质同象置换对磁铁矿表面反应性(如吸附、氧化、还原等性能)的制约机制,最后针对已有的相关研究现状以及面临的挑战,为未来的研究方向提出了一些设想和建议。

Iron oxide and/or hydroxide minerals have played important constraints on the geochemical behaviors of environmental substances. Compared to other iron oxides,magnetite has some unique structural characteristics and surface properties,endowing magnetite with good oxidation and reduction activity. The isomorphous substitution occurred widely in the structure of natural magnetite. To discuss the constraint mechanism of isomorphous substitution on the surface reactivity of magnetite will be helpful to deeply understand the mechanism of magnetite-group minerals in the environmental selfpurification process. This paper has firstly introduced the coordinated state of typical substituting cations and their influences on the physicochemical properties of magnetite,then especially elucidated the constraint mechanism of the isomorphous substitution on the surface reactivity of magnetite(e. g.,adsorption,oxidation,and reduction),and finally proposed some tentative plans and suggestions for future research directions in view of the current research status and facing challenges in this field.