转炉高氧化性炉渣溅渣护炉工艺优化及效果

转炉冶炼低碳钢低磷钢时,终渣氧化性强,渣中w(T.Fe)高达20%~30%,影响到溅渣护炉效果和转炉炉龄。在溅渣开始时采用改渣剂对高氧化性炉渣进行改质,可以降低炉渣中的T.Fe含量,提高炉渣MgO含量,增加炉渣的熔化温度和黏度,溅渣时起渣的孕育时间小于1 min,炉渣中氧化铁与MgO-C炉衬中的碳反应受到抑制,防止溅渣层与炉衬之间气隙的产生,提高溅渣层的抗侵蚀能力,改善溅渣层与炉衬的粘结效果。对冶炼低碳钢低磷钢转炉溅渣护炉工艺的改进,显著提高了转炉的炉龄,吨钢补炉耐火材料消耗下降39%以上。     

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。通过试验及理论计算,在1 600 ℃条件下,炉渣固相率随着渣中(FeO)含量的增加而降低,随着炉渣碱度和(MgO)含量的增加而增加。降低(FeO)含量和提高(MgO)含量可以明显提高固相率。因此,将(FeO)质量分数控制为22.5%~27.0%,(MgO)质量分数控制为8%~12%,碱度控制为3.6左右时,终渣溅渣效果明显提升。     

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。     

溅渣护炉工艺的精确控制技术

研究了转炉炉衬溅渣层的结合机理和侵蚀机理,分析了影响溅渣的各种工艺因素。提出了出钢前利用副枪TSO探头测出的炉渣氧电势数据得出冶炼终点炉渣中Fe O的含量,通过调整炉渣中Fe O含量控制溅渣层的分熔特性,达到减少溅渣层分熔量,提高溅渣层对炉衬保护的技术方案。以宣钢150 t复吹转炉为例,对方案的实施过程进行了说明。     

转炉终渣成分的研究

转炉炼钢过程中终渣的碱度（R）、MgO及FeO含量是炉渣成分最重要的指标参数,合理的炉渣成分是保证冶炼过程脱P、脱S,溅渣护炉等冶金性能的基本前提,通过对马钢第二钢轧总厂炼钢分厂的大量现场终渣成分数据的分析研究,总结出FeO与R、MgO的关系,摸索出适合的终渣成分参数,为控制合理的炉型和提高冶金效果提供巨大帮助。     

转炉用溅渣镁球造渣技术

针对转炉炉渣MgO含量偏低的现象,对转炉使用溅渣镁球代替轻烧白云石造渣技术,合理控制溅渣镁球的加入量,达到降低终渣FeO、提高渣中MgO来迅速降低炉渣过热度等目的,从而可以缩短溅渣时间,提高溅渣层的抗侵蚀能力,最大限度发挥溅渣护炉效果,延长补炉间隔时间,节约耐火材料,提高生产作业率,并降低炼钢的冶炼成本。     

富氧化铁炉渣的溅渣护炉机理

上海第一钢铁（集团）公司30t转炉所用铁水条件较差,导致终渣中氧化铁含量很高。由于转炉出钢温度也偏高,实施溅渣护炉以大幅度提高炉龄比较困难。实验室与工业试验研究结果表明：（1）溅渣层中富氧化镁RO相是冶炼过程中抵抗高温、高氧化性炉渣侵蚀的骨架;（2）溅渣过程中富氧化铁改质渣在炉衬表面出现的异份分流现象有利于溅渣层保留较多氧化镁物相。     

双联炼钢工艺脱碳炉溅渣护炉工艺优化

介绍了唐山不锈钢脱碳炉溅渣护炉工艺优化实践。分析了双联工艺条件下脱碳炉炉渣特点和高氧化性渣对炉衬和溅渣层侵蚀的影响。通过改善终渣成分,优化溅渣工艺参数等措施,提高了溅渣层的抗侵蚀能力,获得了良好的效果。     

210t转炉溅渣护炉用改性料应用研究

随着生产钢种结构的调整,转炉冶炼工艺相应发生改变.为改善转炉炉衬的状况,提高溅渣质量,采用改性料进行溅渣,终渣状况明显改善,取得了良好的溅渣效果.     

Experimental study on slag splashing with modified vanadium slag

Slag splashing is the most effective technology to improve the furnace campaign of converter; however, due to the great difference of composition between the vanadium slag and the steel slag, the technology has not been applied in the vanadium extraction converter. To solve the serious problem of lining erosion in the vanadium extraction converter, in this paper, slag splashing with modified vanadium slag was studied. The results showed that the purpose of adjusting the state of vanadium slag can be achieved through the modification. The modified slag had good slag splashing performance. After slag splashing, the thickness of the furnace was increased by more than 10?mm. The content of CaO in the modified vanadium slag can be controlled less than 3%, and the quality of vanadium slag and semi-steel was not obviously affected. The metallic iron content in the slag was greatly reduced, which was beneficial to reduce the iron loss in the vanadium extraction process.     

提钒转炉溅渣护炉试验研究

溅渣是提高转炉炉龄最有效的技术,但由于钒渣与钢渣成分差异较大,溅渣护炉技术尚未在提钒转炉上得到应用.为解决提钒转炉炉衬侵蚀严重的问题,对改性钒渣溅渣进行了研究.结果表明,通过改性可以达到调整钒渣状态的目的.改性后的钒渣具有良好的溅渣性能,溅渣后炉厚增加10 mm以上.改性钒渣中w(CaO)可控制在3％ 以下,对钒渣和半...     

Converter life enhancement through optimisation of operating practices

Abstract

Converter lining life is an important technical and economic concern of the steelmaking process. An increase in lining life decreases refractory consumption and reduces steelmaking costs. Increased availability of furnaces increases production rates and steel yield. Extended lining life was achieved by utilising the slag as a consumable refractory by splashing it over the lining. Slag splashing is a simple and effective technique followed worldwide to increase the converter life. This paper highlights the online study on various operating parameters and slag characteristics for consistent slag splashing in a 130 t converter. Parameters such as lance height, blow pattern, gas flowrate, bottom purging flowrates, tapping temperature, combination of gunniting with splashing, slag height and slag chemistry, were investigated. An optimised slag has been developed which served effectively to balance the lining erosion during blowing and maintain a uniform thickness throughout the campaign. Some innovative practices and design changes are also discussed. The developed slag regime and optimised parameters have helped in increasing the converter life to an international benchmark. JSW Steel has achieved the converter lining life of 13 771 heats, which is the highest ever recorded in India.     

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。     

济钢超低碳、超低磷钢转炉溅渣护炉工艺

随着超低碳、超低磷钢种冶炼的增多,济钢复吹转炉终点氧含量大幅提高,严重侵蚀了转炉炉衬。从高氧化性炉渣对炉衬的侵蚀机理入手,提出了兼顾溅渣层和炉底的溅渣工艺,介绍了超低碳、超低磷钢溅渣护炉工艺参数的优化及取得的效果。     

转炉溅渣层与镁碳砖炉衬的结合机理

通过对生产现场带有溅渣层的转炉炉衬残砖和试验室小型坩埚溅渣试验结果进行矿相显微结构分析、研究，确定了溅渣层的矿相组成、溅渣层与ＭｇＯ－Ｃ砖结合区域的矿相结构及坩埚溅渣层自上而下的矿相分布规律，并根据矿相结构分析中观察到的烧结层、结合层和溅渣层３个区域，提出了溅渣层与镁碳砖炉衬的结合机理为化学结合、机械镶嵌与化学烧结结合及冷凝结合３种形式。     

氮气转炉溅渣护炉技术

氮气转炉溅渣护炉技术是一项显著提高转炉护龄,降低生产成本的先进技术。介绍了溅渣工艺及溅渣技术的关键因素,并着重论述了保证溅渣技术实施的供氮条件。     

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.     

湘钢转炉溅渣护炉技术的应用研究

介绍了湘钢二炼钢厂50t转炉溅渣护炉技术的应用与效果,主要探讨了冶炼造渣剂,溅渣工艺参数控制及溅潭护炉对钢水质量的影响,提出了今后的改进方向。     

转炉溅渣护炉工艺技术研究

溅渣护炉工艺是近期发展起来的一项新技术，该工艺设备简单，投资少，收效快，操作方便，可大幅度提高衬寿命，进而提高炉龄次数，介绍了溅渣护炉工艺原理，有关参数及经济效益。