CO2吸收模型中容积传质系数的确定

气泡微细化是“原位机械搅拌法铁水炉外脱硫技术”的关键.气液传质系数是研究气液吸收过程的基本参数.本文根据相似性原理建立水模型实验装置,并通过测定NaOH吸收CO2的速率来研究气泡微细化过程,同时根据吸收原理定量计算出容积传质系数Ak及CO2气体利用率η.当溶液pH值从12降低到9的过程中,容积传质系数为2.938×10 4m3/s,本实验所用CO2的利用率的公式可简化为:η=18.98/Qt.本论文的研究结果可为进一步研究吸收速率提供理论依据.     

石灰微观结构对铁水预处理脱硫的影响

采用比表面积1.891~2.664 m²/g和平均孔径575.5~814.9 nm四种不同结构的活性石灰在高真空电弧熔炼旋淬一体机中进行铁水预处理脱硫实验。用扫描电子显微镜分析不同石灰样品表面形貌,并用全自动压汞仪测量石灰的比表面积和平均孔径。实验结果表明铁水脱硫率随着石灰平均孔径的增大而减小,随着比表面积增大而提高;最佳脱硫剂配比为1:50。可将铁水中硫含量从0.014%脱至0.001%。     

On the hot metal desulfurization

Although there is no thermodynamic limitation to the desulfurization of carbon-saturated iron with CaO, the process is well-known to be slow. Consequently, the desulfurization of carbon-saturated Fe-S, Fe-S-Si, Fe-S-Si-Al, Fe-S-Zr alloys by CaO, and Fe-S-Si alloys by CaO-10 % CaF₂ were investigated to determine the reaction mechanism. For this purpose, dense CaO and CaO-10 % CaF₂ discs were cemented to the bottoms of graphite crucibles containing the carbon saturated alloys. The desulfurization experiments were run at 1450°C in an SiC resistance furnace under argon gas atmosphere. The results indicate that the desulfurization of hot metal by CaO is greatly improved by prior addition of aluminum to the hot metal. The addition of 10 % CaF₂ to CaO also increases the rate of desulfurization. Zirconium, which has a stronger affinity for oxygen than aluminum did not increase the rate. SEM and X-ray diffraction studies on the surfaces of CaO discs used to desulfurize carbon-saturated Fe-S, and Fe-S-Si alloys showed that solid CaS, and solid CaS plus small amount of solid 2 CaO · SiO₂ compounds form on the lime surface, respectively. The slow reaction rate with CaO is attributed to the solid reaction products which block the reaction by preventing the occurrence of interfacial turbulence.     

KR法铁水脱硫效果的影响因素分析

简要介绍了210tKR铁水预处理装置的主要设备及工艺流程,根据涟源钢铁厂的具体生产情况,分析了影响210tKR铁水预处理脱硫效果的主要因素如铁水温度、脱硫剂单耗、铁水初始硫含量、搅拌时间等,结果表明脱硫效果随着铁水温度的升高而增加,随着脱硫剂单耗、搅拌时间的增加而增加,但有一较佳值,随着铁水初始硫含量的增加而增加,但有一临界值.     

Effect of FeO in the slag and silicon in the metal on the desulfurization of hot metal

Work has been conducted to investigate the effects of FeO in the slag and silicon in the metal on hot metal desulfurization. Laboratory experimental results show that FeO decreases and silicon increases the rate of desulfurization. Silicon in the metal is consumed by the reduction of FeO and also by the desulfurization reaction. A mathematical kinetic model was developed to describe both the effects of silicon and FeO on desulfurization for the laboratory scale. The model predicts the sulfur and silicon content in the metal and the FeO and sulfur content in the slag as a function of time. It is based on four-component simultaneous mass transfer: sulfur and silicon in the metal and FeO and sulfur in the slag. Experimental results, the development of the kinetic model, and a comparison of the model and experimental results are presented.     

CaO在镁基铁水炉外脱硫工艺中的作用

在镁基铁水炉外脱硫工艺中,单喷镁粉时镁的利用率较低,特别是脱硫目标值较低时,Mg的溶解损失较大,且扒渣比较困难。根据对CaO在镁基铁水炉外脱硫工艺中作用的分析,采用CaO-Mg复合喷吹工艺,特别是铁水目标硫含量较低时,可以减少铁水脱硫所需的镁粉量,降低运行成本。铁水脱硫过程中加入CaO,还有利于改善脱硫粉剂的喷吹效果,并利于扒渣。在CaO-Mg复合喷吹法铁水脱硫工艺中,应根据不同反应阶段的特点,改变CaO和镁粉的喷吹速率。     

KR法铁水脱硫工艺及一键脱硫技术的应用

介绍了KR搅拌法铁水脱硫处理工艺在武钢炼钢总厂二分厂的应用情况以及脱硫的设备参数和操作流程,从搅拌头插入深度、脱硫剂加入时间及搅拌时间这几个方面分析了影响脱硫效果的主要因素,并叙述了3号脱硫站使用的一键脱硫技术的原理、工艺流程及取得的效果.     

铁水脱硫粉剂喷吹罐的工作原理和性能分析

研究了目前铁水脱硫工艺采用的不同喷吹罐的工作原理和性能。研究表明,向上出料的喷吹罐对喷吹速率的调节能力强,但是操作复杂;向下出料的喷吹罐对喷吹速率的调节能力弱,但是结构简单,易于操作,可以利用粉末控制调节阀控制脱硫粉剂的喷吹速率。喷吹罐的流化装置有多种不同的材料和形式,应该根据脱硫粉剂的具体性能参数和喷吹罐的具体结构形式选择不同的流化装置。     

中磷铁水同时脱磷脱硫实验室研究

针对w([P])在0.33%~0.44%的中磷铁水,在1 350℃条件下采用喷吹法对同时脱磷脱硫渣系进行了优化试验。结果表明:CaO过剩系数、氧化剂过剩系数和w(CaF_2)/w(CaO)对脱磷的影响不大,但对脱硫影响显著。综合考虑脱磷率、脱硫率和渣量,最佳渣剂组成为CaO过剩系数45%,氧化剂过剩系数15%,w(CaF_2)/w(CaO)为0.5;用B_2O_3代替CaF_2,须将w(B_2O_3)/w(CaO)控制在0.20以上。     

提高铁水脱硫喷枪寿命的实践

根据济南钢铁集团总公司第一炼钢厂铁水脱硫喷枪的损坏机理,通过改进枪体结构、优化喷枪制作工艺,提高耐材性能指标,使济南钢铁集团总公司第一炼钢厂脱硫喷枪的寿命从平均使用200 min提高到了900 min以上,并很好地解决了铁水复合喷吹脱硫堵枪的问题.