摘要
流态化炼铁工艺作为典型的非高炉炼铁新工艺和新技术之一,不仅可以促进节能减排、降低炼铁成本,还有利于推动钢铁行业的低碳绿色可持续发展。还原气体利用率是流态化炼铁还原工艺的关键参数之一,直接影响炼铁新工艺技术的工业化应用。在对CO和H_(2)混合气体还原铁氧化物热力学分析的基础上,采用流态化还原试验方法研究了铁矿粉流态化还原过程的气体利用率变化规律。利用微型流化床系统进行了铁矿粉的流态化还原试验,以40 mg巴西铁矿粉在流态化状态下被完全还原来研究反应温度、矿粉粒径、气体流量和混合气体体积配比等因素对试验过程还原气体利用率的影响规律。研究结果表明,在试验条件下,降低反应温度和减小矿粉粒径有利于CO气体利用率增加;CO利用率随着气体流量的增加呈现出先增加后减小的趋势,改变CO与H_(2)配比也具有随着CO配比增加CO利用率先增加后急剧下降的类似情况;CO利用率在CO气体流量为400 mL/min、CO体积分数为50%时达到最大值。因此,对流态化预还原过程,应考虑H_(2)的配比情况确定适宜的气体流量,并改善还原的热力学与动力学条件,以尽可能提高还原气体的利用率。研究结果能够加深对流态化气体还原行为的认识,并为流态化炼铁新工艺工程应用的工艺参数选择和反应器设计提供一定的理论支撑。
As one of the typical new non-blast furnace ironmaking processes and technologies,fluidized ironmaking process can not only promote energy conservation and emission reduction,reduce the cost of ironmaking,but also promote the low-carbon green sustainable development of the iron and steel industry.Reduction gas utilization rate is one of the key parameters of fluidized ironmaking reduction process,which directly affects the industrial application of new ironmaking technology.Based on the thermodynamic analysis of the reduction of iron oxide by CO and H_(2) mixed gas,the variation rule of gas utilization rate in the fluidized reduction process of iron ore fines was studied by using the fluidization reduction experiment method.The fluidization reduction experiment of iron ore fines was carried out by using the micro-fluidized bed system.40 mg Brazilian iron ore fines were completely reduced in the fluidization state to study the influence of reaction temperature,particle size of ore fines,gas flow rate and gas mixture ratio on the reduction gas utilization rate in the experiment process.The results show that under the experimental conditions,reducing the reaction temperature and particle size of ore fines would be beneficial to the increase of CO gas utilization rate.With the increase of the gas flow rate,the CO utilization rate shows a trend of firstly increased and then decreased.Changing the ratio of CO to H_(2) also has a similar situation that the CO utilization rate increased first and then dropped sharply with the increase of the CO ratio,and reached the maximum value when the CO gas flow rate was 400 mL/min and volume percent of CO is 50%.Therefore,for the fluidization pre-reduction process,the proportion of H_(2) should be considered to determine the appropriate gas flow rate,and the thermodynamic and kinetic conditions of reduction should be improved to increase the utilization rate of reduced gas as much as possible.The research results can deepen the understanding of the reduction behavior of fluidized gas,and provide a certain theoretical support for the selection of process parameters and reactor design for the engineering application of the new fluidized ironmaking process.
作者
祝明妹
郑忠
唐则吉
许玉忠
何徐
ZHU Mingmei;ZHENG Zhong;TANG Zeji;XU Yuzhong;HE Xu(College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第7期17-26,共10页
Iron and Steel
基金
国家自然科学基金重点项目资助项目(51874056)。
