Effect of Heating Rate on Decomposition Temperature of Goethite Ore

Abstract

The decomposition temperature is available for pure, synthetic, stoichiometric goethite and a particular type of goethite ore. The decomposition temperature depends on the size of grains, temperature, pressure, heating rate and so on. The decomposition temperature of goethite decides the drying and preheating temperature on induration stand during thermal hardening of the pellets. The induration steps are designed based on the thermal behavior of goethite. The goethite ores, because of their chemically combined moisture content, pose special problems. The generation of fines from iron ore due to internal pressure developed from the evaporation of moisture or phase transformation (28% increases in volume) has a harmful effect on induration of pellets and blast furnace performance. Such behavior of iron-bearing materials is evaluated by thermal degradation index. To avoid/control the cracking/breaking of goethite pellet on induration stand, we should be aware of phase transformation temperature and thermal behavior of goethite. Therefore, we can decide the thermal profile for the pelletization of the goethite ore. Therefore, this study is to find out the decomposition temperature of goethite with respect to the mineralogy of ores and heating rate.