Li Ying, Chen Huiting, Hammam Abourehab, Wei Han, Nie Hao, Ding Weitian, Omran Mamdouh, Yan Lixiang, Yu Yaowei
State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferrometallurgy, School of Materials Science and Engineering, Shanghai University, 99 Shangda Rd, Shanghai 200444, China.
Central Metallurgical Research and Development Institute (CMRDI), P.O. Box 87, Helwan, 11421 Cairo, Egypt.
Materials (Basel). 2021 May 30;14(11):2952. doi: 10.3390/ma14112952.
The aim of this study was to investigate the properties of an organic binder used in cold-bonded briquettes (CBBs) prepared from two different iron bearing materials. The applied binder is a type of starch as indicated by chemical analysis, iodine-starch staining and Fourier transform infrared analyses. Thermogravimetric differential scanning calorimetry showed that the binder pyrolysis undergoes four stages: moisture desorption, ash volatilization, pyrolysis of organic matter and decomposition of materials with high activation energy. The difference between the dry and heat-treated samples during the macroscopic failure process is the instability propagation of the crack. The CBB shows a low decrepitation index at 700 °C. The returned fines of CBBs used with the organic binder were applied in two blast furnaces. The industrial trials showed that the CBBs do not influence the performance of the blast furnace and can reduce the fuel consumption rate. The curing rate of the binder decreases, and the growth rate of compressive strength decreases during the curing process. Iron ore particles are bonded together and exist in the form of aggregation after mixing with water and binder. The edges and corners of the particles become blurred, and the original surfaces of the particles are covered with binder film, the surface of which is covered with fine particles. The multi-branched structure of amylopectin provides omnibearing adhesion sites, thus forming binder agglomeration and film leading to a strong adhesion between binder and iron ore particles. Binder film and binder agglomeration work together to make the CBB perform well.
本研究的目的是研究由两种不同含铁材料制备的冷压块（CBB）中使用的有机粘结剂的性能。化学分析、碘-淀粉染色和傅里叶变换红外分析表明，所应用的粘结剂是一种淀粉。热重差示扫描量热法表明，粘结剂热解经历四个阶段：水分解吸、灰分挥发、有机物热解和高活化能材料分解。在宏观破坏过程中，干燥样品和热处理样品之间的差异在于裂纹的不稳定扩展。CBB在700℃时具有较低的热裂指数。使用有机粘结剂的CBB返回粉被应用于两座高炉。工业试验表明，CBB不会影响高炉性能，并且可以降低燃料消耗率。在固化过程中，粘结剂的固化速率降低，抗压强度增长率降低。铁矿石颗粒在与水和粘结剂混合后粘结在一起并以团聚形式存在。颗粒的棱角变得模糊，颗粒的原始表面被粘结剂膜覆盖，粘结剂膜表面覆盖着细颗粒。支链淀粉的多分支结构提供了全方位的粘附位点，从而形成粘结剂团聚和薄膜，导致粘结剂与铁矿石颗粒之间具有很强的粘附力。粘结剂膜和粘结剂团聚共同作用，使CBB性能良好。
