|Cite this article as:|
|Lele Niu, Zhengjian Liu, Jianliang Zhang , Dawei Lan, Sida Li, Zhen Li, and Yaozu Wang, Mineralogical characteristics, metallurgical properties and phase structure evolution of Ca-rich hematite sintering, Int. J. Miner. Metall. Mater.,(2022). https://doi.org/10.1007/s12613-022-2484-6|
The experimental study in this paper was carried out to clarify the mineralogical properties of the newly found calcium-rich iron ore and its behavior in the sintering process. Chemical analysis, laser diffraction, scanning electron microscopy, XRD-Rietveld method,and micro-sintering were used to analyze the mineralogical properties and sintering pot tests were used to study the sintering behavior of calcium-rich iron ore. In addition, a grey correlation mathematical model was used to calculate and compare the comprehensive sintering index under different calcium-rich iron ore ratios. The results and findings demonstrate that the Ca-rich iron ore has coarse grain size and strong self-fusing characteristics with Ca element in the form of calcite (CaCO3) and the liquid phase produced by the self-fusing of calcium-rich iron ore is well crystallized. Its application with a 20% ratio in sintering improves sinter productivity, reduces fuel consumption, enhances reduction index, and improves gas permeability in blast furnace by 0.45 t/(m2·h), 6.11 kg/t, 6.17% and 65.39 kPa·℃ respectively. Ca-rich iron ore sintering can improve the calorific value of sintering flue gas than magnetite sintering, which is conducive to recovering heat for secondary use. As the ratio of Ca-rich iron ore increases, sinter agglomeration shifts from localized liquid-phase bonding to a combination of localized liquid-phase bonding and iron oxide crystal connection. Based on an examination of the greater weight value of productivity with grey relational analysis, Ca-rich iron ore is beneficial for the comprehensive index of sintering in the range of 0-20% ratios. Therefore, it may be used in sintering with magnetite concentrates as the major ore species.