鲕状赤铁矿气体还原动力学研究

发布时间：2018-06-30 10:17

  本文选题：鲕状赤铁矿 + H2　； 参考：《贵州大学》2015年硕士论文

【摘要】：我国鲕状赤铁矿储量丰富,占铁矿石储矿量的1/9,广泛分布在湖南、湖北、贵州等地。由于其矿物本身结构复杂,嵌布粒度极细,且经常与菱铁矿、鲕绿泥石和含磷矿物共生,目前无法得到充分利用,是国内外公认的难选铁矿石之一。但随着高品位铁矿石资源的日渐枯竭以及国外铁矿石价格日益渐长,人们不得不把目光投向低品位铁矿石的开发与利用。贵州鲕状赤铁矿资源储量5亿吨以上,主要分布在赫章、凯里一带,该资源的开发利用可缓解水钢对原料的需求。因此,研究鲕状赤铁矿具有非常重要的意义。实验以贵州赫章鲕状赤铁矿为原料,H2为还原剂,通过研究还原温度、还原时间和添加剂等因素对其还原过程的影响。采用光学显微镜、SEM-EDS和化学成分分析等手段,研究不同因素条件下矿粉的失重率、金属化率及微观形貌等。研究结果表明:还原温度和还原时间对金属化率影响显著,随着温度和时间的增加,金属铁颗粒逐渐变大,矿粉的失重率和金属化率也相应增加;在1100℃、还原时间120min时,试样的失重率和金属化率分别为24.53%和83.25%,且该温度下鲕状结构消失。反应前30min,H2还原鲕状赤铁矿反应速率较快,还原速率受矿粉中氧化亚铁浓度的影响较大;加入8.4%CaO,鲕状赤铁矿还原后的失重率和金属化率进一步提高,所得金属铁杂质含量降低。同时建立了各温度下还原反应的动力学方程,当温度为1100℃,R=1.0时,H2还原鲕状赤铁矿的反应速率最快,速率方程为V=2.63×10-2CFeO0.93。
[Abstract]:Oolitic hematite in China is rich in reserves, accounting for 1 / 9 of the ore reserves, widely distributed in Hunan, Hubei, Guizhou and other places. Because of its complex structure, fine grain size and symbiosis with siderite, oolitic chlorite and phosphorus-bearing minerals, the minerals are not fully utilized and are recognized as one of the refractory iron ores at home and abroad. However, with the depletion of high-grade iron ore resources and the increasing price of foreign iron ore, people have to pay attention to the development and utilization of low-grade iron ore. Oolitic hematite resources in Guizhou province are mainly distributed in Hezhang and Kaili areas. The exploitation and utilization of oolitic hematite resources in Guizhou province can alleviate the demand for raw materials of water steel. Therefore, it is of great significance to study oolitic hematite. The effect of reduction temperature, reduction time and additive on the reduction process of He-zhang oolitic hematite from Guizhou Province was studied by using H _ 2 _ 2 as reducing agent. By means of optical microscope SEM-EDS and chemical composition analysis, the weight loss rate, metallization rate and microstructure of ore powder under different factors were studied. The results show that the reduction temperature and reduction time have a significant effect on metallization rate. With the increase of temperature and time, the iron particles become larger, and the loss of weight and metallization rate of ore powder increase accordingly, and at 1100 鈩，

本文编号：2085944