Processing of magnesium bearing materials by dry chlorination - An overview of kinetic aspects

5th International Conference New Achievements in Materials and Environmental Science

材料科学;生态环境科学

Kanari, N.^1 ; Diot, F.^1 ; Allain, E.^1 ; Yvon, J.^1

Université de Lorraine, UMR 7359 CNRS, CREGU, GeoRessources Laboratory, 2 rue du Doyen Roubault, TSA 70605, Vandoeuvre-lès-Nancy Cedex

F-54518, France^1

关键词: Activation energies (Ea);    Bearing materials;    Dry chlorinations;    Isothermal conditions;    Kinetics parameter;    Rate of chemical reaction;    Reaction mechanism;    Selective chlorination;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/879/1/012011/pdf
DOI  :  10.1088/1742-6596/879/1/012011

来源: IOP

【 摘 要 】

This paper is focused on the reactivity of Cl2towards MgO in presence of a reducing (CO) and oxidizing (O2) agent at temperatures up to 1025 °C. Kinetics parameters are determined by thermogravimetry under isothermal conditions. The overviewed results showed that the carbochlorination (Cl2+CO) occurred at temperatures lower than oxychlorination (Cl2+O2). The reaction of MgO with Cl2+CO from 425 °C to 600 °C proceeds with an activation energy (Ea) of about 49 kJ/mol, while the reaction rate does not longer depend on the temperature between 600 and 675 °C. The reaction of MgO with Cl2+O2at 850-1025 °C was characterized by a value of Eaof 214 kJ/mol indicating that the overall rate of the process is controlled by the rate of chemical reaction. Oxychlorination can also be used for removing the impurities contained in the industrial magnesium raw materials. Further, the behavior of the MgO in chlorine atmosphere leads to give an insight about the reaction mechanisms useful for the selective chlorination of complex ores and concentrates containing magnesium oxide.