The Role of Thermal Treatment on the Activation of Ilmenite Ores for Leaching
Thermal treatment of mineral ores can initiate thermal phase transformations which can affect either their activation or deactivation, subsequently influencing their ability to dissolve in a leaching reagent. The formation of rutile and hematite from ilmenite minerals, for example, has been suggested to occur through a series of reduction and segregation reactions. This process has been used in beneficiating low-grade weathered ilmenite ores to higher grade rutile. Despite decades of research, the mechanism of this process is not well understood, because dissolved intermediates are poorly crystalline and are difficult to quantify, with the exception of the final rutile products. Previous studies have shown that disrupted intermediate phases, by thermal treatment, are most susceptible to reagent attack and can often demonstrate activation effects.In this study, synchrotron based X-ray diffraction method was used to investigate in-situ and in real-time the transformation of ilmenite minerals to rutile and hematite during calcination. The rate of formation and disappearance of specific Bragg peaks during the reaction and thermal decomposition of the mineral were used to derive an understanding of the solid-state reactions. The effects of the mineral transformation were validated by laboratory based batch calcination and leaching in sulphuric acid. The results suggest that transformation of major mineral phases occurs within of specific window of operation and thermal treatment appears to influence the extent of activation and leachability of ilmenite minerals.
Ilmenite Heating Calcination Phase Transformation X-ray diffraction
W. S. Eu M. Valix W. H. Cheung
School of Chemical & Biomolecular Engineering, The University of Sydney, Darlington, Australia
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
1734-1739
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）