Growth of metallic iron particles during reductive roasting of boron-bearing magnetite concentrate  

含硼铁精矿还原焙烧过程中金属铁颗粒的生长规律

作　　者：ZHANG Xin LI Guang-hui RAO Ming-jun MI Huan-peng LIANG Bin-jun YOU Jin-xiang PENG Zhi-wei JIANG Tao 张鑫;李光辉;饶明军;米寰鹏;梁斌珺;游锦香;彭志伟;姜涛(School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China)

机构地区：[1]School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2020年第5期1484-1494,共11页中南大学学报（英文版）

基　　金：Project(51804346)supported by the National Natural Science Foundation of China;Project(2019JJ50767)supported by the Natural Science Foundation of Hunan Province,China;Project(KY[2017]125)supported by Youth Foundation of Guizhou Education Department,China。

摘　　要：The growing characteristics of metallic iron particles during reductive roasting of boron-bearing magnetite concentrate under different conditions were investigated.The size of the metallic iron particles was quantitatively measured via optical image analysis with consideration of size calibration and weighted ratio of image numbers in the core,middle and periphery zones of cross-section of pellets.In order to guarantee the measurement accuracy,54 images were captured in total for each specimen,with a weighted ratio of 1:7:19 with respect to the core,middle and periphery section of the cross-section of pellets.Increasing reduction temperature and time is favorable to the growth of metallic iron particles.Based on the modification of particle size measurement,in terms of time(t)and temperature(T)a predicting model of metallic iron particle size(D),was established as:D=125−0.112t−0.2352T−5.355×10^−4t^2+2.032×10^−4t∙T+1.134×10^−4T^2.研究了不同还原条件下含硼铁精矿在焙烧过程中金属铁颗粒的生长规律。采用光学显微镜获取还原球团的数字图像,考虑到球团不同部位金属铁颗粒生长情况的差异,采用回归拟合分析得到内、中、外区域的权重比例为1:7:19,每个样品根据此权重比例共获取54张图像。基于修正后的金属铁颗粒尺寸的测定方法,建立了铁颗粒平均粒径D(μm)与还原温度T(℃)、时间t(min)之间的回归模型:D=125-0.112t-0.2352T-5.355×10^-4t^2+2.032×10^-4tT+1.134×10^-4T^2。

关 键 词：ludwigite ore reductive roasting metallic iron grain growth size measurement 

分 类 号：TF55[冶金工程—钢铁冶金]