Some basic properties of granules from ore blends consisting of ultrafine magnetite and hematite ores  

作　　者：Cong-cong Yang De-qing Zhu Jian Pan Yue Shi 

机构地区：[1]School of Minerals Processing and Bioengineering,Central South University

出　　处：《International Journal of Minerals,Metallurgy and Materials》2019年第8期953-962,共10页矿物冶金与材料学报（英文版）

基　　金：Financial supports from the National Torch Program of China (No.2011GH561685);Hunan Provincial Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources are sincerely acknowledged

摘　　要：Some basic properties of granules,including the granule size distribution,packed-bed permeability,and chemical composition of the adhering layer,were investigated in this study for four iron ore blends consisting of 5wt%,25wt%,and 45wt%ultrafine magnetite and 25wt%ultrafine hematite concentrates.The effects of varying the sinter basicity(CaO/SiO2 mass ratio=1.4 to 2.2)and adding ultrafine concentrates on the variation of the adhering-layer composition and granule microstructure were studied.Moreover,the effect of adhering-layer compositional changes on sintering reactions was discussed in combination with pot sintering results of ore blends.Increasing sinter basicity led to an increase in the basicities of both the adhering layer and the fine part of the sinter mix,which were higher than the overall sinter basicity.When the sinter chemistry was fixed and fine Si-bearing materials(e.g.,quartz sand)were used,increasing the amount of ultrafine ores in the ore blends tended to reduce the adhering-layer basicity and increase the SiO2 content in both the adhering layer and the fine part of the sinter mix,which will induce the formation of low-strength bonding phases and the deterioration of sinter strength.The adhering-layer composition in granules can be estimated in advance from the compositions of the-1 mm fractions of the raw materials.Some basic properties of granules, including the granule size distribution, packed-bed permeability, and chemical composition of the adhering layer, were investigated in this study for four iron ore blends consisting of 5 wt%, 25 wt%, and 45 wt% ultrafine magnetite and 25 wt% ultrafine hematite concentrates.The effects of varying the sinter basicity（CaO/SiO2 mass ratio = 1.4 to 2.2） and adding ultrafine concentrates on the variation of the adhering-layer composition and granule microstructure were studied.Moreover, the effect of adhering-layer compositional changes on sintering reactions was discussed in combination with pot sintering results of ore blends.Increasing sinter basicity led to an increase in the basicities of both the adhering layer and the fine part of the sinter mix, which were higher than the overall sinter basicity.When the sinter chemistry was fixed and fine Si-bearing materials（e.g., quartz sand） were used, increasing the amount of ultrafine ores in the ore blends tended to reduce the adhering-layer basicity and increase the SiO2 content in both the adhering layer and the fine part of the sinter mix, which will induce the formation of low-strength bonding phases and the deterioration of sinter strength.The adhering-layer composition in granules can be estimated in advance from the compositions of the-1 mm fractions of the raw materials.

关 键 词：iron ORE GRANULE adhering layer MAGNETITE concentrate SINTER BASICITY 

分 类 号：TF[冶金工程]