低镁钒钛磁铁矿内配碳球团还原控制机制研究

Reduction Control Mechanism of Carbon-burdened Low-Magnesium Vanadium-Titanium Magnetite

为开发利用辽宁朝阳地区低镁钒钛磁铁矿资源,以石墨为还原剂,研究了还原温度、还原时间对低镁钒钛磁铁矿内配碳球团还原过程的影响,并进行了反应动力学研究,并采用扫描电镜-能谱仪(SEM-EDS)等分析方法对还原控制机制进行了分析。通过计算分析确定低镁钒钛磁铁矿还原过程限制性环节为O原子在产物层内的扩散,反应表观活化能为228.80 k J/mol。研究结果表明,低镁钒钛磁铁矿与攀西地区钒钛磁铁矿相比,易于还原。当还原温度超过1 200℃时,球团均能快速进行反应;延长还原反应时间,还原产生的金属铁从矿物颗粒外表面到内部依次析出,球团内部新生相界面逐渐清晰。

In order to exploit the low-magnesium vanadium-titanium magnetite resources in Chaoyang, Liaoning Province, influences of reduction temperature/time on the reduction process of carbon-burdened V-Ti magnetite pellets were studied with graphite as reduetant, and the reaction kinetics were investigated while the reduction mechanism was analyzed by SEM and EDS. Based on the calculation, the diffusion of O atom within the grains of reduced products was the control step and the apparent activation energy of the reaction was 228.80 kJ/mol. The results show that low-Mg V-Ti magnetite ore was easier to be reduced compared with ore from Panxi area. The pellets can be quickly reduced at above 1 200 ℃, and with the extension of reduction time, metallic iron generates and separates out along mineral grains from the exterior to the interior, and fresh interfaces inside the pellets are gradually clear.