利用TG-DSC方法对铁矿石分解及软熔特性的研究

The research on the decomposition and softening-melting properties of iron ore by TG-DSC

利用TG-DSC方法在空气气氛下,对澳大利亚和巴西共13种铁矿石的结晶水分解特性、矿石中Fe2O3分解特性及铁矿石的软熔特性进行了试验研究。研究结果表明,澳大利亚铁矿石和巴西铁矿石的结晶水开始分解温度、分解温度区间、结晶水含量及结晶水分解吸热量均存在差异,经计算,如果烧结混合料中结晶水升高1个百分点,那么在烧结过程中,由结晶水分解吸热量增加而需要多消耗的热量为2.31×104kJ。澳大利亚和巴西铁矿石的Fe2O3分解起始温度、终止温度及分解温度区间相近,而澳大利亚矿的Fe2O3分解吸热量却明显高于巴西矿的Fe2O3分解吸热量。铁矿石软熔过程生成的液相量与矿石中SiO2含量密切相关,SiO2含量越高,矿石在软熔过程中生成的液相量越多,η值越小。

13 kinds of iron ores （6 from Australia and 7 from Brazil） were studied on their properties concerning CW （Combined Water） decomposition, Fe203 decomposition and softeningmelting in air atmosphere through the characterization method of TG-DSC （ThermogravimetryDifferential Scanning Caloremetry）. The experimental results of the Australian ores and Brazilian ores differ in terms of the initial temperature, temperature range and endothermic amount of CW decomposition, and besides, the content of CW. It is estimated that for every percent increase of CW content in sintering raw material, the extra thermal amount absorbed in the process is about 2.31 x 104 kJ. As to the decomposition of Fe203, the initial temperatures, terminal temperatures and temperature ranges of the Australian and Brazilian ores are quite closer. However, the endothermic amount of Fe203 decomposition of the two turns out rather different： the endothermic capacity of Fe203 decomposition of the Australian ores is greater than that of the Brazilian ores. Furthermore, the liquid amount generated in the softening-melting process is closely related to the SiO2 content in iron ore. The higher SiO2 the ore contains, the more liquid volume, it will generate in the softening-mehing process of iron ore.