共查询到17条相似文献,搜索用时 62 毫秒
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为使环保措施和高炉/转炉法生产的进一步合理化,对积极回收利用废钢铁的要求越来越高,关于熔化大量废钢的技术是一种利用现有转炉,以廉价块煤作为热源,从炉顶加入熔化废钢的技术,本文通过5t试验转炉和实际转炉进行试验,调查了废钢的熔化过程,煤的吹出情况和向熔池的增碳行为,最后,在250t转炉上确立了以50%废钢比进行废钢熔化操作的工艺方法。 相似文献
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煤氧竖炉熔化废钢的热态试验研究表明,采用煤氧竖炉熔化废钢在工艺上是可行的。通过考察焦炭加入量,二次燃烧给氧量,氧煤比对金属收得率,废钢熔化时间,熔清碳,二次燃烧率等指标的影响,得到煤氧竖炉熔化工艺最佳的工艺参数,在此工艺参数范围内,熔清碳=1.0%~2.0%;金属收得率=94%~95%;熔化时间〈38min熔清硫〈0.070%,热效率为26%~29%。煤氧竖炉熔化废钢工艺的开发对我国电炉和转炉工艺 相似文献
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为了解废钢的熔化速度和熔化机理,在250 kg感应炉中进行了热模拟试验。测量熔化速度采用直径为[?20~?50 mm]的Q235圆钢,熔池温度为1 300、1 400和1 600 ℃。根据试棒直径不同确定在熔池中浸泡时间。根据钢棒浸泡前后的质量和尺寸差别,计算出熔池为1 300、1 400和1 600 ℃时,其质量熔化速度分别为1.8~4.0、3.5~6.5和12.6 g/s;径向熔化速度为0.012~0.026、0.035~0.045和0.060 mm/s。熔池液体与试棒之间的对流换热系数在1 400 ℃时为32 931 W/(m2·℃),1 600 ℃时为32 884 W/(m2·℃)。在温度为1 300 ℃时,碳在液体与试棒之间的对流传质系数为6.3×10-5 m/s,温度为1 400 ℃时为6.4×10-5 m/s。热模拟试验所测得的钢棒熔化速度、液-固相之间的对流换热系数、碳的对流传质系数都与国外冶金工作者的试验结果相近,可以作为炼钢生产中计算废钢熔化的基础数据。 相似文献
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In order to reveal the mechanism of heat and mass transfer in the melting process of steel scrap, linear dissipative thermodynamics was applied to investigate the heat transfer between liquid steel and steel scrap, and the diffusion and mass transfer of carbon and the coupling relationship between them. Combined with the moving boundary layer theory model, the mass conservation equation of carbon at the interface was obtained when the liquid steel temperature is 1773K, the carbon mass fraction of liquid steel is 1.0 mass%, the scrap radius is 0.03m and the initial temperature of scrap is 300K, that is, the scrap melting model based on the theory of linear heat dissipation mechanics. The accuracy of the model is verified by previous experimental results. The scrap melting model based on linear heat dissipation mechanics established can predict the changes of carbon content, carbon activity and interface temperature with time in the scrap melting process, and provide theoretical guidance for practical industrial production. 相似文献
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摘要:旋转电极电渣重熔通过改变结晶器内熔体的流动和传热规律,增强了渣池与电极间的对流换热,在提高电极熔化速率和生产效率方面具有巨大潜力。提出了电渣重熔过程电极熔化速率的求解方法,并考虑了电极旋转时的强制对流,基于多物理场耦合模型预测了电极直径、转速对电极熔化速率的影响规律。结果表明,随着转速提高,金属液滴由从电极中心滴落向电极边缘滴落转变,高温区由渣池外侧向渣池中心移动。当转速从0增大至90r/min,55mm直径电极的熔化速率从7.90g/s增大至9.68g/s,对比固定电极,转速为90r/min时,生产效率最多提高了22.5%;进一步增大转速,电极熔化速率反而减小。存在一个最佳转速可使熔化速率达到最大,且该最佳转速随着电极直径的增大而减小。 相似文献
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Steel scrap is of great benefit for environmental protection. In converter steelmaking, bottom carbon injection was applied to enhance the scrap ratio and in EAF steelmaking, submerged carbon powder injection was used to accelerate the smelting of scrap. In these two cases, carbon powder is directly injected into molten metal to improve the scrap melting with effective carburization capacity and intense stirring effect. In this study, the induction furnace experiments were carried out to study the melting characteristics of steel scrap with different carbon contents and bottom-blowing gas flow rates. The results show that larger carbon content and faster fluid flow can promote scrap melting because the carburizing reaction can be accelerated by larger carbon concentration gradient and the heat transfer can be enhanced by larger stirring intensity. Finally, the convective mass transfer coefficient and heat transfer coefficient between steel bar and molten metal were also calculated. 相似文献
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摘要:传统CaO-SiO2系保护渣在浇铸高锰高铝钢时,渣中SiO2易被钢中Al还原,造成保护渣成分改变和性能恶化,危害铸坯表面质量和连铸过程顺行。为了抑制钢 渣反应,旨在减少渣中氧化性组分的低反应性,CaO-Al2O3基渣系是重要选择方向。在评估高锰高铝钢凝固特性和传统反应性保护渣基础上,提出了低反应性保护渣基本性能要求,并采用单纯形法设计了CaO-Al2O3基保护渣系的试样组成。通过测试实验渣样的熔化特性和流动特性,获得了5组低反应性连铸保护渣熔化流动特性的成分控制区域。典型区域基本性能为:熔化温度(半球点温度)900~1100℃,1300℃的黏度0.1~0.2Pa·s,转折温度900~1150℃。 相似文献
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摘要:通过取样检测并结合热力学和动力学计算研究了氧化镁质(MgO)、镁铝尖晶石质(MgO·Al2O3)和氧化钙质(CaO)3种坩埚和2种真空压力(50~100Pa和5~10Pa)对AerMet100超高强度钢脱氮的影响。实验结果表明:随着精炼时间增加,3种坩埚在2种真空压力下的钢液中N质量分数都逐渐减少。相比之下,CaO坩埚脱氮效果最佳,2种真空压力下30min时N质量分数均减少到0.0005%。动力学计算结果表明:MgO和MgO·Al2O3坩埚在2种真空压力下的钢液中O和S活度较高,脱氮反应均服从2级,即钢液脱氮受界面化学反应控制;而CaO坩埚在2种真空压力下的钢液中O和S活度较低,脱氮反应均服从1~5级,即钢液脱氮由液相边界层传质和界面化学反应共同控制。此外,减小真空压力,脱氮速率加快,有利于钢液脱氮。 相似文献
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