为考察物料形式对深度还原效果的影响,以湖北官店鲕状赤铁矿为原料,考察了造块和散料两种物料形式对鲕状赤铁矿深度还原效果的影响。结果表明:造块物料还原产品铁金属化率和磁选精矿指标均优于散料还原产品铁金属化率和磁选精矿指标;随着还原温度的升高、还原时间的延长和给料粒度的减小,两种物料形式还原产品铁金属化率和磁选指标均逐渐提高。造块物料具有良好的热传导性能和微细空隙结构,使其深度还原效果较好,金属铁颗粒粒度较大,颗粒形状也较规则。对还原产品SEM分析结果表明:造块物料经深度还原后金属铁颗粒粒度明显大于散料,物料造块焙烧后对鲕粒的破坏更加显著,说明物料造块后更加有利于铁矿物的还原。造块能够使热量更快传导,铁氧化物界面保持较高浓度的还原气氛,进而加快了金属化反应进程。试验结果可以为深度还原工艺给料形式选择及还原工艺条件优化提供参考。
In order to investigate the influence of material status on deep reduction effect,influence of two material status as briquetting and loose ore on oolitic hematite ore deep reduction effect was investigated using oolitic hematite ore from Guandian,Hubei Province as raw material. The results showed that iron metallization ratio and magnetic separation index of briquetting were better than loose ore's; with increase of reduction temperature,prolong of reduction time and the decrease of raw ore granularity,reduction products iron metallization ratio and magnetic separation index of different material status both increase.Briquetting was superior to the loose ore on reduction index,metal particle size and particle shape due to its better heat conduction and micro-gap structure. Scanning Electron Microscope( SEM) analysis on reduced products reflected that metal particle sizes of briquetting were obviously larger than loose ore's. Meanwhile,the roasting destruction of oolite was more heavily as the ore to be briquetted,means that briquetting was more benefit to the reduction of iron mineral. Briquetting could provide relatively faster heat conduction and higher concentration of reduction atomosphere which abounded in the interface of iron oxide,and then accelerated the process of the metallization reaction. Test results could provide references for the selection of feeding form and the optimization of reduction conditions in further application.