Theory and practice of the optimizing of charging structure in EAF steelmaking

The viewpoint about harmful residual element control, the charging structure and its influence on production index due to the diversification of raw material in EAF steelmaking was expatiated. The residual element control model, the concept of the proportion of iron and steel and the charging structure triangle were putted forward. Based on theoretical calculation and statistical analysis, the influence of charging structure on production index was discussed, and it was found that the utilizing efficiency of energy will reduce as the proportion of iron and steel in EAF steelmaking increases.

Improvement of power input for steelmaking process in high impedance EAF

According to the electrical operation and steelmaking theory of EAF, animproved power input procedure of 70 t high impedance EAF in Nanjinng Iron and Steel Corp. Ltd. wasstudied. The investigation method, process and result for use of power supply of high impedance EAFwas proposed, and the optimized power-supply curve to EAF steelmaking practice was given, andelectrical operation was improved, the electric energy consumption can be reduced by 25 kW. T/t, andpower supply time can also be reduced 3 min.

EAF-LF炼钢流程中钢水回磷的热力学分析

本文对钢水回磷进行了热力学计算和分析,得知EAF LF炼钢流程中钢水回磷的根本原因是熔池温度升高、炉渣氧化性减小和炉渣碱度降低,并针对宝山钢铁股份有限公司150tEAF炉冶炼钢管钢过程、定量计算了熔池温度、炉渣氧化性及炉渣碱度变化对钢水回磷量的影响。计算结果表明,在LF精炼的热力学条件下,渣中无磷存在;EAF下渣量及铁合金种类对LF精炼钢水回磷量也有影响,EAF每下渣100kg,钢水增磷0.00032%,锰铁合金的增磷作用大于硅铁合金。每加入1kg t锰铁合金使钢水增磷不少于0.0002%。由计算及分析可知,为防止钢水回磷必须密切关注EAF终点升温过程、严格控制EAF下渣量并采用低磷锰铁合金。

太钢60t EAF-LF-VD-2.5t铸锭流程冶炼低钛轴承GGr15钢的实践

电弧炉采用低钛铁水、合金和造渣材料,偏心炉底出钢,出钢合金化,LF精炼时,用Si、Al复合脱氧和碱度3～5的CaO-MgO-Si0_2-Al_2O_3渣系,30 Pa VD处理,以及保护浇铸等工艺措施,Φ150 mm锻造棒材的分析结果为GGr15轴承钢中的氧含量为4.5×10^(-6)～9×10^(-6),Ti含量为0.001 0%～0.001 5%,钢中有少量5μm TiN夹杂,达到特钢优质低钛轴承钢的质量要求。

EAF-LF-VD-WF-CC工艺生产低氮钢技术

综述了用EAF－LF－VD－WF－CC工艺流程生产低氮钢的现状及采取的主要技术措施。降氮措施有：电炉内激烈的碳沸腾、造泡沫渣、EBT出钢及采用DRI，VD炉内真空底吹氩搅拌；保护措施有：LF炉内气氛控制及连铸钢包与中间罐间的长水口加氩气环保护。

UHP－EAF工艺软件的开发

本文运用“黑箱”的方法对超高功率电弧炉炼钢工艺过程做了系统分析，基于物料衡算、能量衡算和化学平衡建立的数学模型，使用ＢＡＳＩＣ、ＤＢＡＳＥ等高级算法语言，对电弧炉炼钢工艺过程计算机操作软件进行了开发研究．

Activity of Reducing Steel Slag of EAF

Reducing steel slag （RSS） was mainly acquired from five electric-arc furnace （EAF） steelmaking plants （among them, the products of two plants were carbon steel and those of other plants were stainless steel） for research tests. The chemical properties, compound compositions, activities and contents of main expansive compounds were tested. The results showed that the field sampled RSS had a very high crystallinity and hydraulicity with main chemical compositions close to those of Portland cement. It can be known from the study that in case of C/S ratio higher than 2.0, the main compound compositions are C2S, C3S, C2F and f-CaO. However, after the RSS was stored for six months, an obvious variation occurred with potential pre-hydration in RSS, where the SO3 content was slightly reduced and the compressive activity index was obviously higher than that at the 28th day.

Optimization of power input diagram of 50 t UHP-EAF

In order to improve operation for shortening tap to tap time and saving electrical energy, on the base of no-linear reactance model, the electrical characteristics of the 50 t UHP-EAF in Fushun Special Steel Co. Ltd. were analyzed. Considering steelmaking process conditions, the optimum power-input diagrams were investigated, which can save energy, lower consumption, and raise productivity. This has been verified by production contrast tests. Application of the optimum curve in 50 t UHP-EAF indicates that research method is correct, the 50 t UHP-EAF runs smoothly with lowering electrical energy by 29.35 kW.h/t and shortening power on time by 3 min. The general steps of making optimum power-input specification is also given.

Optimization of power input diagram of 50 t UHP-EAF

In order to improve operation for shortening tap to tap time and savingelectrical energy, on the base of no-linear reactance model, the electrical characteristics of the50 t UHP-EAF in Fushun Special Steel Co. Ltd. were analyzed. Considering steelmaking processconditions, the optimum power-input diagrams were investigated, which can save energy, lowerconsumption, and raise productivity. This has been verified by production contrast tests.Application of the optimum curve in 50 t UHP-EAF indicates that research method is correct, the 50 tUHP-EAF runs smoothly with lowering electrical energy by 29.35 kW-h/t and shortening power on timeby 3 min. The general steps of making optimum power-input specification is also given.

70t UHP-EAF脱磷技术实践

对70UHP-EAF的脱磷操作及其控制要点作了详细的介绍、分析。

EAF-CCM炼钢工艺实践

韶钢炼轧厂电炉炼钢工序的生产工艺按EAF炉-LF-CCM执行,其中LF炉除了担负精炼功能外,同时在生产中起重要的组织平衡作用.针对LF炉变压器出现的突发性故障,摸索出异常情况下生产组织的新模式,即实现了EAF-CCM工艺的直接对接,为今后该生产模式应用提供了科学依据和实践经验.

底吹搅拌技术在电弧炉中的应用与发展

发展电弧炉短流程炼钢是钢铁工业实现“双碳”目标的重要途径。近年来,现代电弧炉技术发展迅速,电弧炉底吹搅拌技术也在不断进步和推广,对电弧炉生产的高效化和节能化作出了重要贡献。针对电弧炉底吹搅拌技术的机理、工艺特点、系统组成、气体种类、底吹元件类型及工艺布置方式进行综述,并对底吹技术的应用情况进行总结分析。模拟计算得出,远离底吹装置的区域,钢液流速明显偏低。结合炉型特点布置底吹装置及优化底吹气量,可改善熔池动力学条件,促进钢液元素传质,实现降低能耗和原材料消耗、提高生产效率的效果。深度开展底吹技术研发,与吹炼、供电、喷粉等工艺技术耦合,并结合新炉型特点制定底吹工艺制度,实现智能化底吹是发展现代电弧炉短流程技术的重要方向。

电弧炉炼钢高效节能技术的发展现状

目前,中国钢铁行业作为碳排放量最高的制造行业仍以高炉-转炉长流程为主,这使得我国钢铁工业实现碳中和面临巨大挑战。相比于高炉-转炉长流程炼钢工艺,以废钢为主要原料,电力为能源介质的电弧炉短流程炼钢工艺碳排放量约为高炉-转炉长流程的1/3,具有良好的降碳效应。并且随着我国环保需求和我国废钢供给量的不断攀升,同时受国家“十四五”规划电弧炉发展政策,在国家“碳达峰、碳中和”的大背景下,短流程电弧炉炼钢能耗低、碳排少的优势越来越明显,未来电弧炉短流程炼钢工艺将更快地朝着高效节能、绿色化生产方面发展,逐渐成为我国重要的炼钢工艺。主要从节能降耗的角度出发,总结国内外短流程电弧炉炼钢高效节能技术的发展概况,介绍其特点及发展现状。

基于电极加热的方形单体废钢熔化特性研究

基于100 t电弧炉建立了废钢熔化的三维几何模型,研究了热源、废钢尺寸及留钢量对废钢熔化速率的影响。结果表明:在70 t留钢量大尺寸废钢熔池中,60 MW热源条件下废钢熔化速率高于无热源条件;在70 t留钢量、60 MW热源条件下,小尺寸(即尺寸减半)废钢的完全熔化时间为44.6 s,其熔化速率远超过大尺寸废钢的熔化速率。在此基础上,研究了不同留钢量对废钢熔化速率的影响,结果表明,60 t留钢量时废钢熔化速率最快,其完全熔化时间为44.3 s,40 t留钢量熔池废钢熔化速率最慢,浸没80 s仍未熔化,因此,过大和过小的留钢量均不利于废钢熔化。原因在于,在熔池升温过程中,大留钢量熔池升温较慢,在熔池降温过程中,小留钢量熔池降温较快,较低的熔池温度会降低废钢所得热通量,不利于废钢熔化。

国内废钢-电炉炼钢发展及展望

针对国家对“碳达峰,碳中和”及炼钢行业的发展要求,为实现短流程炼钢占比目标,分析了我国炼钢行业面临的问题,提出了电炉炼钢未来的发展方向,同时总结了各类电炉炉型在我国的应用情况和特点,结合欧洲电炉现状探讨了我国电炉炉型的发展。

电炉短流程回顾和发展中的若干问题

回顾以电弧炉—精炼—连铸—连轧为代表的炼钢短流程在国内外的发展概况,简述电炉短流程的工艺革新与技术进步,讨论废钢资源和电能短缺、残存元素富集和二恶英污染等阻碍我国电炉钢发展的若干问题,并从循环经济的要求出发对电炉炼钢短流程工艺和装备的进一步改革与完善提出看法。

大容量直流电弧炉接入对电网谐波的影响分析

大容量直流电弧炉是高功率的非线性负荷,运行时会产生大量谐波,影响电网的电能质量。基于某钢铁集团130t直流电弧炉配电网架构及参数,建立了含治理装置的大容量直流电弧炉的动态仿真模型,分析了大容量直流电弧炉的谐波发射特性及其影响因素。通过现场实测和仿真结果,分析了大容量直流电弧炉接入电网后的谐波特性,验证了静止无功补偿器(SVC)的滤波效果,为直流电弧炉接入电网后的监督和治理提供了参考。

现代电弧炉炼钢技术的发展

现代电弧炉冶炼技术是围绕缩短冶炼周期这一核心发展起来的 ,从能量平衡的角度出发 ,提出了电弧炉冶炼周期与各工艺参数和设备参数之间的关系式。简单地介绍了世界电弧炉冶炼技术的发展以及围绕超高功率供电、增加化学热和物理热以缩短冶炼周期的冶炼技术进步。肯定了近十年来我国发展现代电弧炉炼钢流程所取得的显著成果 ,分析了存在问题的原因 ,提出了提高电炉钢市场竞争力 。

大型电弧炉炼钢用氧的模拟实验及其工业应用

根据相似原理 ,利用 1∶ 10比例的有机玻璃模型研究了不同吹氧参数时的熔池混匀时间、传质系数、渣 -钢液乳化时间和废钢熔化时间等问题。此外 ,还测定了氧枪的射流流场。根据实验结果制定的电弧炉提高用氧量工艺制度 。

交流电弧炉炼钢过程谐波状况的实测研究

由于电弧电阻具有非线性特性 ,不管电弧炉的容量和功率水平如何 ,都是电网的非线性负荷。即使电网电压本来是理想的正弦波 ,电极电流却会出现波形畸变 ,即除基波电流外 ,还包含有各高次谐波。特别是在电弧炉炼钢的熔化初期 ,由于产生大量的高次谐波注入电网 ,能引起电网电压的剧烈波动。根据南京钢铁集团有限公司 70 /10 0 t高阻抗电弧炉实测谐波参数 ,结合电弧炉炼钢的工艺特点 ,研究大型交流电弧炉炼钢过程中的谐波问题 ,并讨论了谐波与操作电抗的关系。