低磷钢冶炼的理论和工艺问题

低磷钢是纯净钢生产的重要部分,从钢包回磷控制和脱磷、锰铁合金脱磷两方面开展低磷钢冶炼的相关理论及工艺研究.结果表明控制钢液脱磷和回磷的CaO基钢包顶渣存在一个临界碱度和临界氧化性,而锰铁合金氧化脱磷存在一个临界碳含量[%C]*,它对应着最大磷分配比LP和最小锰分配比LMn,采用BaO基渣系对锰铁合金脱硅脱磷联动处理获得45%～50%的脱磷率.     

锰铁合金用CaO渣系脱磷的热力学研究

对高碳锰铁合金用CaO渣系进行了氧化脱磷的热力学研究,认为合适的氧位,选好渣系,降低P2O5活度,会取得较好的保锰脱磷效果,且经济效益显著。     

不锈钢高铬铁液的脱磷

讨论和分析了高铬铁液氧化脱磷和还原渣系脱磷的特点以及碳的影响，提出高铬铁母液用氧化法脱磷，废钢返回法冶炼不锈钢用还原法脱磷。     

高速钢脱磷研究

本文对高速钢(W_6M_(05)Cr_4V_2)用氧化法、氯化法及还原法脱磷进行了试验和探索,着重讨论了高速钢氧化脱磷的效果及影响因素。     

高碳锰铁氧化脱磷的理论分析

对高碳锰铁氧化脱磷保锰进行了理论分析。ＣａＯ系渣不能实现氧化脱磷保锰;而ＢａＯ系渣中实现氧化磷保锰,但ＭｎＯ活度及ＢａＯ活度必须很高,同时锰铁中硅含量必须很低。适当降低反应温度有利于氧化脱磷保锰,高碳锰铁中碳不利于脱磷,但适当降低温度能有效提高脱磷效率。１６７３Ｋ条件下,当「％Ｃ」＝３．８时,脱磷效果最佳。     

转炉炼钢低碱度钢渣的高效脱磷与固磷

磷的去除由磷的氧化与磷的固化两个环节组成,氧化脱磷需要钢渣的大渣量、高碱度、高氧化性;但是从固磷角度来讲,渣中较低的FetO有利于固磷相C2S(2Ca O·Si O2)的稳定存在。在较低碱度条件下,通过控制转炉冶炼中后期冶炼枪位、供气强度,控制冶炼中后期渣中的氧化亚铁,通过渣相分析发现,R=3.1、w((Fe O))=13.9%的渣系中固磷相C2S比例明显高于R=4.0、w((FeO))=19.7%渣系中固磷相C2S的比例,并且前者的渣中平均w((P2O5))=2.5%,部分炉次w((P2O5))可以达到3.55%,高于后者的平均值2.22%。通过采用低碱度、低氧化铁渣系,实现了炼钢辅料消耗低于常规冶炼工艺的目的。     

CaO—SiO2—MnO—CaF2渣系对硅锰合金脱磷的研究

本文讨论了硅锰合金氧化脱磷的热力学条件。在硅钼棒炉中,采用 CaO-SiO_2-MnO-CaF_2渣系对硅锰合金进行了氧化脱磷实验,取得了较高的脱磷和脱硫率。     

BaO-CaO渣系不锈钢氧化脱磷研究

针对不锈钢氧化脱磷容易导致合金元素铬损耗的问题,在中频感应炉中采用20%CaO-45%BaO-15%Fe2O3-10%Cr2O3-10%CaF2渣系进行氧化脱磷试验。在热力学计算的基础上,通过调配BaO含量、钢液中初始碳含量和钢水处理温度,获得脱磷率不低于50%,脱磷过程中铬氧化量不超过8%的试验结果。试验研究表明:该试验渣系的脱磷效果比CaO渣系好,与BaO渣系相当;随着钢液中碳含量的提高,脱磷率增加、铬损减小;随着熔炼温度的升高,脱磷率降低、铬损减小,在1 750 K时脱磷率和铬损耗处于最优化水平。     

BaO渣系对高铬钢选择氧化脱磷的研究

在理论计算的基础上,对高铬钢的选择氧化脱磷进行了实验室研究。发现BaO—BaCl_2—氧化物渣系对高铬钢的脱磷是完全可行的。当用Cr_2O_3替代Fe_2O_3作为氧化剂来控制氧化时,可以达到去磷保铬的目的。并用BaO—BaCl_2(BaF_2)—Cr_2O_3渣系对高铬钢进行了在低[C]低渣量下的脱磷,为工业生产提出初步建议。     

锰铁脱磷的研究及其同生铁脱磷的比较

借鉴各种已有合金的脱磷法对锰铁脱磷进行了比较系统的实验研究、探索和热力学基础分析,并在此基础上就锰铁的脱磷路线提出了自己的见解。实验和热力学分析表明,石灰渣系和苏打渣系的氧化脱磷对液体锰铁不能奏效,苏打和锰熔体还有激烈的相互作用。铁水中含锰超过约5％(石灰渣下)或约15～20％(苏打渣下),脱磷效率明显变坏。惰性气流中用     

锰铁合金脱磷综述

随着钢铁工业的快速发展，对钢水洁净度的要求日益增高。锰铁合金作为炼钢过程的脱氧剂及合金添加剂，其品位受到冶金界的极大关注。文章主要概述锰铁合金脱磷渣系的研究现状及其应用于锰铁工业化脱磷中存在的不足，指出锰铁合金脱磷渣系的开发方向，并重点对含稀土氧化物渣系用于锰铁合金脱磷的可能性进行分析预测。     

用预熔渣对铁水脱磷的试验研究

以铁水和脱磷粉剂为研究体系,应用CaO-Fe2O3-CaF2渣系的脱磷粉剂和其预熔渣对铁水脱磷,研究结果表明,用Al2O3和白云石部分替代萤石,预熔后的脱磷渣都比未预熔渣的脱磷速度快,且二者的处理过程结果基本相似,脱磷粉剂经过预熔处理,成渣迅速,预处理时间缩短,温降小,脱磷率高。     

复吹转炉冶炼82B脱磷工艺研究与实践

在分析了复吹转炉脱磷的热力学与动力学条件的基础上,通过延长吹炼前期温度在1 400～1 500℃的冶炼时间,实现钢—渣充分脱磷、前期双渣后进行少渣冶炼、出钢碳按0.15%～0.40%控制,实现了复吹转炉吹炼前期高效脱磷,为82B系列产品批量生产提供了质量保证。     

Effect of change of slag phase on dephosphorization of ��double- slag+slag- remaining�� steelmaking technology

The microstructure and phase constituent of dephosphorization slag of ??double- slag+slag- remaining?? steelmaking technology were observed and analyzed by SEM, part of the slag were heat treatment, and the effect of the change of slag phase on dephosphorization was studied. The research results show that the phase of dephosphorization slag A1-A3 with high dephosphorization rate are composed of calcium ferrite, complex liquid silicate phase (Ca3TiFeSi3O12, Ca54MgAl2Si16O9) and 2CaO??SiO2(C2S) solid phase solution with calcium phosphate (2Ca2SiO4??Ca3(PO4)2, Ca7(PO)4(SiO4)2), the main phase of dephosphorization slag A4 with low dephosphorization rate is liquid phase, the main phases of dephosphorization slag A5 are MnFe2O4, MnV2O4, Ca12Al14O33, little phosphorus rich calcium silicate solid phase is found in both dephosphorization slag A4 and A5; the phase of dephosphorization slag A3 changes little before and after heat treatment, but the phase of dephosphorization slag A4 changes greatly after heat treatment, which changing to liquid phase and white branches like RO phase; the dephosphorization slag of ??double- slag+slag- remaining?? steelmaking technology contain many un- dissolved CaO, but little is found in decarburization slag, the formation of C2S solid phase in dephosphorization slag plays an important role to accelerate the dephosphorization reaction.     

利用转炉渣对铁水脱磷的动力学

在实验室条件下，模拟转炉渣组成，利用CaO-SiQ-Fe2O3-MnO2-MgO-P2O5-Al2O3-CaF2系熔剂对铁水进行脱磷预处理。实验发现：随着预处理时间的延长，铁水发生回磷反应。在铁水回磷状态下，测定了磷在渣中的传质系数。讨论了回磷原因和抑制铁水回磷反应的措施。在此基础上，确定了合适的铁水脱磷预处理时间和转炉渣的优化组成。     

转炉脱磷工艺的最新进展

转炉脱磷工艺利用了转炉容积大的特点,可以实现转炉前期快速高效低碱度脱磷.脱碳渣的循环利用降低了石灰等辅料消耗和渣量.在低温低碱度转炉脱磷的条件下,低温在热力学上有利于脱磷,但温度过低会使渣过于粘稠而影响动力学条件并使倒渣困难;适当提高碱度,脱磷效果较好.随着渣中氧化铁含量的上升,脱磷效果先上升后下降.转炉脱磷渣中固液两...     

Kinetic Model of Hot Metal Dephosphorization by Liquid and Solid Coexisting Slags

In most cases, hot metal dephosphorization slag is saturated with dicalcium silicate, and the partition ratio of phosphorus between dicalcium silicate and liquid slag is high. These results indicate the important role of solid dicalcium silicate in dephosphorization. In order to understand the reaction kinetics and obtain an optimum treatment method, it is very important to know the influence of solid phases in the slag. In this study, a new reaction model for hot metal dephosphorization considering the effects of dicalcium silicate and dissolution rate of lime is proposed. In the new dephosphorization model, in addition to the reaction rate between liquid slag and metal, the partition between dicalcium silicate and liquid slag and the dissolution rate of lime are also considered. The dephosphorization reaction of hot metal by the liquid slag phase was calculated by using the coupled reaction model. The calculated results demonstrated the importance of dicalcium silicate in dephosphorization. Also, in some cases, the dissolution rate of lime affected the dephosphorization behaviour.     

脱磷炉利用脱碳炉返回渣的试验

为了达到节能降耗的目的,脱磷炉采用回吃脱碳炉返回渣的工艺。主要研究了脱碳炉渣的熔化特性以及作为炉料在脱磷炉中的应用效果。结果表明,通过每炉次加入约3.5t的脱碳炉渣,可平均节约1.01t石灰,4.71kg/t钢铁料消耗,脱磷炉终点炉渣的岩相组成主要由硅酸二钙、RO相、玻璃相和少量的金属铁粒组成。加入返回渣后脱磷炉终点炉渣中硅酸二钙和铁酸二钙含量有所增加,玻璃相含量降低,炉渣碱度有所升高,脱磷炉终点钢水成分控制水平有所提高。由此表明,采用脱碳炉渣返回脱磷炉循环利用减少了石灰等原辅料和钢铁料消耗,同时达到了预期的脱磷效果。     

转炉冶炼低磷洁净钢的工艺开发和实践

 转炉具备冶炼低磷钢的生产能力,但生产超低磷9Ni钢,转炉脱磷工艺仍然是主要难点和研究重点。分析了钢水温度、炉渣碱度、FeO和渣量等对转炉脱磷的影响规律,并结合现场工装设备条件,对转炉双联法、三渣法、双渣法3种脱磷模式进行试验对比。双联脱磷工艺半钢温降大、单炉周期长、生产组织难度大,三渣法操作过程复杂、终点磷控制优势不明显。双渣法冶炼周期短,通过优化转炉脱磷工艺,实现了采用双渣法冶炼工艺生产超低磷钢,简化了超低磷钢转炉冶炼流程,提高了生产效率。研究了转炉脱磷主要工艺参数,分析得出采用脱碳氧枪喷头时,供氧流量按脱碳吹炼流量的83.5%控制,可达到良好的脱磷效果并减少铁水碳的烧损;脱磷期半钢碳含量不宜控制过低,半钢碳质量分数为3.0%～3.5%时能保证前期的脱磷效果和脱碳期的热量。脱磷期温度控制在1 300～1 350 ℃,脱磷率较高也有利于炉渣熔化。炉渣碱度为1.8～2.2时,可保证较高的脱磷率和化渣效果。一次倒渣量40%以上,脱碳期终点温度按1 590～1 610 ℃控制,终渣FeO质量分数不小于20%,终渣碱度大于6,转炉终点磷质量分数可降低到0.002%以下。采用下渣检测系统和滑板挡渣操作,严格控制下渣量,出钢采用磷含量低的合金,炉后钢水增磷可控制在小于0.000 5%。通过工业试验,实现了铸机成品磷质量分数小于0.002%。     

Melting Characteristics of Recycling Slag in Decarburization Converter and Its Application Effects

 The steel slag in the decarburization converter is treated by the little water-spreading (LWS) and the heat-stewed (HS) methods, which is used as the furnace burden of the dephosphorization converter. The slag characteristics by the LWS and the HS methods and its application effects as the furnace burden are researched. The results show the moisture content in the HS slag is higher than that of the LWS slag. There is higher total iron content in the HS and the LWS slags and almost same melting point. The dicalcium silicate content in the LWS slag is higher than that in the HS slag. The tricalcium silicate in the LWS slag is lower than that in the HS slag. There are a lot of calcium ferrite in the LWS and the HS slags, which is beneficial to dephosphorization and slag melting. The LWS and the HS slags are added to dephosphorization converter each charge by 3 or 6 t. The results show that the saving lime is 0. 7-1. 0 t for each charge. The petrographic constitute of final slag for the dephosphorization converter by adding the LWS and the HS slags is dicalcium silicate, RO phase and glass phase. There are a little calcium ferrite phase in the LWS slag, which is helpful to dephosphorization. So there are better dephosphorization effects for the LWS and HS slags.