Adhesive Behaviour of BOF Slag to BOF Lining Refractory in Slag Splashing Process

A slag layer is formed when slag is splashed onto refractory lining in BOF slag splashing process. The melting temperature of the slag layer and the adhesion of the slag layer to the lining refractory have an important effect on slag splashing and BOF lining life. This study investigates the adhesive behaviour of slag with different composition to lining refractories. It is shown that the slag can adhere to MgO particles in MgO‐C bricks well and no reaction is found between the MgO particles and the slag layer, but a gas gap exists at the interface between the slag layer and the MgO‐C matrix and there are iron granules within the slag layer, when the FeO content in the slag is high. The adhesion of the slag layer to the lining refractory can be improved with decreasing FeO content in the slag and lower carbon content in the MgO‐C bricks. BOF refractory lining life can be greatly increased due to better adhesion, high melting temperature, and stronger wear‐resistance of the slag layer.     

转炉溅渣护炉炉渣物性研究

针对转炉后吹和正常吹炼终渣∑FeO变化较大的特点,对炉渣的成分,熔化性温度和岩相结构进行研究,研究结果为转炉溅渣护炉终渣成分的调整提供了一些依据。     

转炉炼钢渣磷元素的富集及影响因素

为了研究炼钢过程中出现的低碳低磷钢冶炼困难以及转炉终点补吹回磷的现象,以转炉炼钢渣相为研究对象,利用扫描电镜测量分析了渣相的微观组成与C_2S(2CaO·SiO_2)富磷相在渣中的比例。研究结果表明,转炉脱磷由"氧化脱磷"+"固磷"两个环节组成;渣中SiO_2通过影响C_2S量的多少对脱磷产生影响,渣中FeO质量分数高,会分解C_2S相进而导致钢水回磷;温度高导致固磷相分解,研究结果表明,通过控制转炉终渣固磷相熔点高于钢水温度,可实现低温出钢。     

溅渣层形成和对炉衬保护机理的研究

通过对溅渣转炉残砖的成分和矿相分析,讨论了高ＦｅＯ炉渣溅渣形成的溅渣层化学成分变化和岩相结构特点;分析提出溅渣层的形成机理和对炉衬的保护作用。实验研究证明,溅渣结合层的化学成分与终渣有明显的差别。结构     

转炉溅渣护炉改质剂的开发研究

影响转炉溅渣护炉效果的关键因素是终渣成分的控制,采用改质剂对转炉终渣成分进行调整,降低渣中FeO含量和炉渣温度,提高MgO含量和炉渣熔点及粘度,有利于改善炉渣与炉衬的粘结效果,并提高溅渣层的耐蚀性能,缩短溅渣起孕时间,在一定程度上抑制炉渣中铁的氧化物与炉衬中石墨的反应.     

转炉溅渣护炉的炉渣控制及炉衬侵蚀机理

利用副枪在转炉吹炼过程中取样、测温和对炉衬残砖的化学成分、岩相、流动温度的测定结果,研究了宝钢转炉溅渣护炉炉渣的控制及炉衬侵蚀机理。结果表明：转炉终渣ＭｇＯ含量应控制在１０ ％ 左右、溅渣层的熔损主要发生在炉温较高的吹炼后期,而镁碳砖的侵蚀是由于炉渣渗入镁碳砖的气孔和裂缝中,使其脱碳和渣化,在高温下流入渣层所致。     

梅钢转炉上应用滚筒处理钢渣的研究

梅山炼钢厂对转炉钢渣主要采取滚筒渣处理工艺,经处理后渣颗粒度小于5 mm的比例在85%左右。滚 筒渣是一种预熔渣,其主要成分为CaO、SiO 2 、FeO,具有熔点低、碱度高、氧化性高等特点,将滚筒渣作为造渣剂可 促进转炉冶炼前期的化渣速度,提高炉渣碱度和氧化性,降低冶炼成本。梅钢在滚筒渣回收利用方面进行了有效 探索,实践表明:使用滚筒渣后,吨钢石灰消耗降低6.5 kg/t,终渣碱度提高0.3,磷分配比提高5.3且波动范围变 窄,钢铁料消耗降低4.6 kg/t。     

Difference in BOF Slag Splashing in US and China

Slag splashing is a relatively new technique thathas been used successfully to enhance refractory lifein BOF′s.During the last ten years,slag splashinghas been used by many steel works in the US[1— 3 ] .Recently,slag splashing has also been applied tomore than twenty steel works in China. Althoughthese steel works are successful to varying extentswith slag splashing,some differences are exhibitedbetween the US and Chinese steel works because ofdifferent conditions in their BOF steelmaki…     

复吹转炉最佳成渣路线的探讨

复吹转炉冶炼过程中不同的成渣路线直接影响着冶炼操作的稳定性、终点的命中率和炉衬的寿命。为此从炉渣碱度和炉渣氧化性两个方面讨论了复吹转炉冶炼低磷铁水和磷含量较高的铁水的成渣路线。结果表明,由于冶炼操作参数的不同,冶炼磷含量较高铁水的炉渣中的∑FeO含量和炉渣碱度比冶炼低磷铁水时高得多,并在此基础上提出了复吹转炉冶炼过程中的最佳成渣路线。     

提高转炉渣体积安定性的实验研究

转炉渣具有高碱度的特点,当碱度大于2时转炉渣中的氧化钙将有部分以游离氧化钙（f CaO）的形式存在。f CaO是造成转炉渣膨胀的主要因素。在熔融态加入不同比例的高炉渣,结合SEM分析了熔融反应后产物的结构,采用压蒸法测定并分析对比了熔融反应前后转炉渣安定性的变化。实验结果表明,熔融态加入高炉渣可显著改善其安定性,冷却方式影响产物结构,对其体积膨胀率影响不大,为转炉渣的应用提供依据。     

100t转炉用含钛铁水冶炼高碳钢的留渣+单渣操作实践

针对100t转炉用含钛铁水冶炼高碳钢的前期成渣难于熔化、脱磷率低的问题,分析了含钛铁水转炉炼钢的成渣过程和炉渣的物理特性,开发了留渣+单渣工艺技术。循环利用终点炉渣,充分发挥渣中10%～13%FeO高（FeO）含量的特点,快速把含钛铁水冶炼前期的CaO-TiO₂-SiO₂三元渣系转变为CaO-TiO₂-SiO₂-FeO四元渣系,脱除钢中大部分磷。控制终渣碱度大于3.2、（TiO₂）含量小于5%,使转炉出钢[C]≥0.20%、[P]≤0.014%,转炉炼钢脱磷率达到88%～92%,石灰消耗下降到28 kg/t钢。     

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In order to study the property of semisteel slag during BOF double slag process and achieve effective utilization, CaO-MgO-SiO2-FetO slag had been chosen as fundamental slag system in the experiment. The slag mineral composition and microstructure characteristics were analyzed by X-ray diffraction (XRD) and the backscattered electron images of scanning electron microscopy (SEM) with energy dispersive spectrometer analysis (EDS). The results show that the main mineral composition of semisteel slag are merwinite (C3MS2), MgO-FeO solid solution (RO) and monticellite (CMS), the minor minerals are dicalcium silicate (C2S) and calcium silicate (CS). The main microstructure characteristics of semisteel slag can be classified into three categories: The grey phase is C3MS2 and CMS, the white phase is RO and the mixed phase is rhodonite or compound phase of silicate and RO. The mineral phase and morphology are affected by slag basicity and the slag cooling speed. The semisteel slag can be reused in many fields, such as metallurgical industry, construction industry and agriculture industry, etc.     

溅渣护炉工艺探讨

从炉渣对炉衬和溅渣层的侵蚀机理入手,提出了兼顾冶金和溅渣双重效果的直接造渣工艺,探讨了终渣碱度、MgO、FeO含量等的调整范围,分析了溅渣操作中枪位、时间等的控制和炉底上涨的原因,以期更好地运用溅渣护炉技术。     

CaO-SiO_2-FeO-P_2O_5-Al_2O_3脱磷渣系中组元活度的计算

2CaO·SiO_2-3CaO·P_2O_5含磷固溶体的生成可提高转炉液相渣的脱磷能力,减少渣量.但目前CaO-SiO_2-FeO-P_2O_5-Al_2O_3渣系中各组元活度的变化规律尚不明确,无法为分析含磷固溶体的形成机理提供理论依据.为此,本文依据分子离子共存理论建立了熔渣组元的活度模型,分析了不同条件下组元活度的变化规律.结果表明:随渣中Al_2O_3含量的增加,2CaO·SiO_2、3CaO·P_2O_5、3FeO·P_2O_5的活度逐渐降低;随着碱度的增大,3CaO·P_2O_5的活度升高,2CaO·SiO_2、3FeO·P_2O_5的活度则呈先升高后降低的趋势;随着渣中FeO含量的增加,2CaO·SiO_2、3FeO·P_2O_5及CaO·Al_2O_3的活度逐渐增大,并在w(FeO)为15%时达到最大值,之后逐渐降低;升高温度会导致CaO、3CaO·SiO_2的活度增大,2CaO·SiO_2的活度降低.     

转炉溅渣护炉调质剂的开发研究

影响溅渣护炉效果的终渣成分的控制,主要是控制终渣中ＦｅＯ％、ＭｇＯ％和Ｒ。通过试验室小型热态模拟实验,测定了溅渣的侵蚀量,炉渣半球熔点,并分析炉渣的显微结构,探讨了溅渣层的侵蚀机理,提出了溅渣护炉的终渣成分大致分别为ＭｇＯ＝８％－１０％,ＦｅＯ＝１０％－１３％,Ｒ＝３．５左右。     

攀钢半钢吹炼条件下的溅渣护炉

攀钢转炉采用溅渣护炉提高炉龄已经取得了很好的成绩。本文主要报告Ｖ．Ｔｉ氧化物对炉渣熔点，粘度和ＭｇＯ饱和溶解度影响的研究结果，并提出了有关溅渣护炉渣系参数的建议。     

150t转炉脱磷炉渣控制工艺的实践

通过对150t转炉3000炉次冶炼数据的分析,得出炉渣中FeO 10%~17%,炉渣熔点1450℃以下,粘度1.0~1.2P时转炉炉渣氧化性IOS和炉渣光学碱度Λ_x对渣-钢磷分配比L_p的影响。为提高炉渣的脱磷能力,在转炉冶炼模型中动态设定石灰加入量,促使终渣光学碱度接近目标范围Λ_x=0.74±0.01,渣组成接近于2CaO·SiO₂相;当前冶炼模型中优先选择铁水还原性指数RIi目标为5.8~6.6,吹氧指数OMI设置目标1.05~1.20,优化炉渣氧化性指数IOS在10~15,能减少钢铁料损失和保证炉渣良好的脱磷效果。     

转炉渣与镁质耐火材料的润湿机制

 采用静滴法研究了2种情况下转炉渣与炉衬耐火材料的润湿性。当转炉渣与耐火材料直接接触时,转炉渣不熔化,当用刚玉坩埚将两者隔开时,界面处发生反应性润湿,动态接触角随温度升高而单调减小,铺展面积随时间成线性增加。渣中FeO含量由于镁碳砖基板表面的碳及中间产物CO的还原而降低,导致炉渣熔化性温度升高而未熔化。液态熔渣沿镁碳砖表面的气孔和裂纹向基体内扩散、渗透,渣中铁氧化物与镁碳砖机体内的MgO反应生成含高熔点相的黄色渗透层,起到保护炉衬的作用,从而解释了炉渣与耐火材料的粘附机制,为优化溅渣护炉工艺,合理调整炉渣成分和选择耐火材料等工艺操作提供理论依据。     

High Temperature Properties of BOF Slag and its Behaviour in the Blast Furnace

Slag formation in the bosh and raceway is an important issue in the blast furnace process. SSAB works in Luleå operate with 100 % olivine pellets. A small amount of basic fluxes is added from the top, slag and limestone are used. To improve the control of slag formation, a concept with injection of BOF slag was evaluated and tested in the LKAB experimental blast furnace (EBF). In this paper, the behaviour of BOF slag as a slag former, when it is top‐charged or tuyere‐injected, is evaluated based on the results from a laboratory study including reduction tests, softening and melting tests, XRD analyses and SEM analyses. Samples taken from the EBF during excavation, and with a burden probe during operation, are examined. The evaluations show that the melting point of BOF slag is quite low and will not be increased, because of the partial reduction that occurs in the BF shaft. When carbon is present at high temperatures, reduction proceeds and a high basicity slag with a high melting point, consisting of di‐ and tricalcium silicates, is formed. When pellets with a basicity of B2 ~ 1 are used, a slag with similar properties can be formed as a result of interaction with the BOF slag. BOF slag in combination with olivine pellets with a low basicity generates a slag with intermediate basicity and the reduction of iron oxides in the slag has a small effect on the melting temperature. The BOF slag decreases the melting point of coal and coke ashes.     

减轻低碳低磷钢冶炼炉衬侵蚀及炉渣成分优化

通过实验室管式高温炉蘸渣试验和理论计算,研究了转炉冶炼低碳低磷钢的终渣(FeO)含量、(MgO)含量和碱度对炉渣物化性能和溅渣护炉炉衬保护的影响.试验优化前,终炉渣(FeO)质量分数为31.5％,(MgO)质量分数为8％,通过调整炉渣碱度,炉渣的固相率依然接近0％,炉渣溅渣后难以残留在炉壁上,不能对炉衬起到保护的效果....