| Magnetic roasting technique is one of the most effective operations in the treatment of low-grade ores. By the basic research in the previous few years, our research group of Xi’an University of Architecture and Technology has developed a new suspended magnetic roasting technology for the siderites, meanwhile as the early results revealed, this process is practical and feasible. This article focuses on the ultra-low-grade siderite wastes, which can not be employed by the baking approach with rotary kiln, using the new suspended roasting technology to analyze the main parameters influencing the whole process and explore new ways to maximize utilizing iron ore resources.In our experiment, the main raw material was siderite taken from Daxigou and the tests were conducted on the self-made hot modeling system of small size. The research emphatically studied the influence of roasting atmosphere and temperature operation conditions on siderite roasting indicator, respectively. Furthermore, to investigate the roasting conditions, phase analysis of the roasted ores was done and the optimized baking condition was discovered.As the results showed, when the calcination temperature was controlled at 740℃and the oxygen content inside the reactor was 0%~1% for the raw materials with 15.06% iron grade in the raw Siderite materials, the magnetic concentrate iron grade and the obtained recovery rate can reach 53.28% and 70.53%, respectively. By analyzing the titration results of calcined iron ores, the orders of the phase composition are as follows: Fe3O4〉Fe2O3〉FeCO3〉Fe2SiO4. With the enhancement of oxygen content, the content of hematite raises, simultaneously when temperature rises, the content of iron silicate does not change significantly. |
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