Mechanism of high pressure roll grinding on compression strength of oxidized hematite pellets  

作　　者：范建军 邱冠周 姜涛 郭宇峰 郝海正 杨永斌 

机构地区：[1]School of Minerals Processing and Bioengineering,Central South University [2]Taiyuan Iron and Steel(Group)Co.Ltd.

出　　处：《Journal of Central South University》2012年第9期2611-2619,共9页中南大学学报（英文版）

基　　金：Project(50725416) supported by the National Natural Science Funds for Distinguished Young Scholars of China

摘　　要：The mechanism of high pressure roll grinding on improvement of compression strength of oxidized hematite pellets was researched by considering their roasting properties. The results indicate that oxidized hematite pellets require higher preheating temperature and longer preheating time to attain required compression strength of pellets compared with the common magnetite oxidized pellets. It is found that when the hematite concentrates are pretreated by high pressure roll grinding （HPRG）, the compression strengths of preheated and roasted oxidized hematite pellets get improved even with lower preheating and roasting temperatures and shorter preheating and roasting time. The mechanism for HPRG to improve roasting properties of oxidized pellets were investigated and the cause mainly lies in the increase of micro-sized particles and the decrease of dispersion degree for hematite concentrates, which promotes the hematite concentrate particles to be compacted, the solid-phase crystallization, and finally the formation of Fe203 bonding bridges during subsequent high temperature roasting process.The mechanism of high pressure roll grinding on improvement of compression strength of oxidized hematite pellets was researched by considering their roasting properties.The results indicate that oxidized hematite pellets require higher preheating temperature and longer preheating time to attain required compression strength of pellets compared with the common magnetite oxidized pellets.It is found that when the hematite concentrates are pretreated by high pressure roll grinding(HPRG),the compression strengths of preheated and roasted oxidized hematite pellets get improved even with lower preheating and roasting temperatures and shorter preheating and roasting time.The mechanism for HPRG to improve roasting properties of oxidized pellets were investigated and the cause mainly lies in the increase of micro-sized particles and the decrease of dispersion degree for hematite concentrates,which promotes the hematite concentrate particles to be compacted,the solid-phase crystallization,and finally the formation of Fe2O3 bonding bridges during subsequent high temperature roasting process.

关 键 词：hematite concentrate PELLET high pressure roll grinding （HPRG） specific surface area lattice defect dispersion degree micro-sized particle 

分 类 号：TD951[矿业工程—选矿]