A non-invasive process for sorting of alumina rich iron ores

Abstract

The present invention first time relates an Infrared (IR) thermography based process for sorting of iron ores consisting of alumina-rich particles of relatively low thermal absorptivity as compared to iron particles in the ores. The technique primarily consists of selection of iron ores with Fe compositions ranging from 53% - 69% and alumina (Al2O3) 0.35% - 11% , grinding the ores up to the particle size ranging from -100 mm +10 mm. The iron ore fines are uniformly heated using heat source of wavelength ranging from 10-2 to 10-6 m for a period of time sufficient to create a difference in IR emission between the ore particles. The thermal image of the heated ores is captured by infrared thermography. The alumina rich iron ores will have lower temperature than the ores with high iron low alumina content. Alumina rich iron ores can be thus identified by observing the temperature profile of these ores. This process of ore recognition will be useful in improving the feed quality to the blast furnace in Iron & Steel industry by rejecting the alumina rich ores. In addition to improve the productivity of Blast furnace this process can also reduce the load of washing plant of steel Industry.