Study On Granulation Gas-Based Magnetic Roasting In Utilizing The Low-Grade Iron Ores

Minerals resources is the material base of human social civilization, and is a non-renewable natural resources.lt is the increasing demand for mineral resources in the development of society. With the price increase of imported iron ore and increasingly dried up rich ore in China, domestic steel industry is facing a huge supply pressure for raw materials. Study on comprehensive utilization of low grade iron ore resources, for the healthy and stable development of China’s iron and steel industry is a great significance.A limonite-based low-grade iron ore resources is targeted in this article, and Study on granulation-gas based magnetic roasting-separation process and appropriate technology。Thermodynamic and kinetic theory, application and analysis of phase for x-ray diffraction analysis, microscopy and electron microscopic scan test technology of iron reduction mechanism and mechanism of process indicators.1. Study on mineralogy of iron ore showed that the ore is a low grade iron ores, that the main form is limonite ore, burning large; The main gangue is quartz, lower harmful impurities. The most of mineral in iron ore is Poor level crystals, and smooth iron particles surface, particle cube, ball formed ball performance is poor.2. Part damp milling granulation and pre-oxidation-reduction roasting process to achieve a homogeneous magnetic roasting for poor balls of low grade iron ore. Part damp milling improved granularity, enhanced granulation. Iron ore become into Fe2O3, and leave the material in uniform high temperature by Oxidizing roasting, and it is an important role in rapid, uniform quality, high performance magnetic roasting and magnetic roasting time reduced from10min to8min. When The50%part of damp milling, granulating balls for2-5mm, nitrogen protection Preheat5min in725℃; magnetic roasting atmosphere CO/CO2/N2is20/40/40, temperature725℃, time10min, when, magnetic roasting and restored to38.78%, grinding time to90s, magnetic strength is100KA/m at this time, result is the concentrate grade60.23%, recovery80.26%.. 3、For low grade iron ores which contain a variety of iron oxides, such as limonite, and Hematite, magnetite, granulating-pre-oxidation-reduction roasting process, can effectively achieve a uniform reduction with a appropriate atmosphere and temperature.