论文部分内容阅读
The microwave-assisted reduction behaviours of two low-grade iron ores having a similar Fe content of 49wt％ but distinctly differ-ent mineralogical and liberation characteristics were studied. Their performances in terms of the iron grade and recovery as obtained from stat-istically designed microwave (MW) roasting followed by low-intensity magnetic separation (LIMS) experiments were compared. At respect-ive optimum conditions, the titano-magnetite ore (O1) could yield an iron concentrate of 62.57％ Fe grade and 60.01％ Fe recovery, while the goethitic ore (O2) could be upgraded to a concentrate of 64.4％ Fe grade and 33.3％ Fe recovery. Compared with the goethitic ore, the titano-magnetite ore responded better to MW heating. The characterization studies of the feed and roasted products obtained at different power and time conditions using X-ray diffraction, optical microscopy, vibrating-sample magnetometry, and electron-probe microanalysis explain the se-quential reduction in the iron oxide phases. Finally, taking advantage of the MW absorbing character of the titano-magnetite ore, a blend of the same with the goethite-rich ore at a weight ratio of 60 : 40 (O2 : O1) was subjected to MW roasting that resulted in a concentrate of 61.57％ Fe grade with a Fe recovery of 64.47％.