攀钢高炉不同炉料相互作用机理试验研究

为探究攀钢高炉不同炉料在软熔过程中的相互作用机理,进行了单种原料及其混合矿软熔性能的测定以及由两种炉料组成的混合矿在特定温度软熔性能测定的中断试验。在试验条件下,块矿的滴落温度T_d最低。与球团矿相比,烧结矿的软化终了温度T₄₀低、滴落温度T_d高、软化温度区间ΔT_s窄、熔化温度区间ΔT_m宽。与烧结矿和球团矿相比,混合矿的滴落温度T_d明显降低。块矿软熔以后在荷重的作用下渗入烧结矿和球团矿的空隙间,促进其与烧结矿或球团矿中物相的相互侵蚀和元素在不同物相间的迁移,从而加速混合矿的软化熔融。     

宣钢高炉含铁炉料熔滴性能

对宣钢高炉炉料结构进行了熔滴性能试验研究。单矿的熔滴试验结果表明:宣钢常用的2种烧结矿软化性能较好,但滴落性能较差,1 520℃仍未滴落;3种球团矿中自产球总体熔滴指标最好但软化区间最长(313℃);2种块矿中PB矿开始软化温度最低软熔区间最长,试验中未能滴落。蒙古矿软熔性能较好,但滴落温度高达1 518℃。通过对15种配矿方案进行的熔滴试验,结果表明:降低烧结矿配比,提高PB矿比例可改善炉料的熔滴性能。在试验条件下,配矿方案为"烧结矿68%+球团矿16%+PB矿16%"的炉料结构熔滴性能最佳。     

济钢用铁矿石软熔滴落性能研究

利用RDL-02装置对济钢高炉现用烧结矿、球团矿及拟用烧结矿软熔滴落性能进行研究分析。研究结果表明：60烧结矿、120烧结矿各项软熔滴落性能相近,320烧结矿开始软化温度、开始熔化温度都比60烧结矿、120烧结矿高,最大压差为11608Pa,低于另2种矿,320烧结矿软熔性能略优于60烧结矿和120烧结矿,为高炉配料提供了科学依据。     

氧气高炉块矿与烧结矿软熔过程交互作用

 以不同预还原度的块矿及块矿与烧结矿的混合矿为研究对象,利用单颗粒荷重软化试验装置,考察了氧气高炉及传统高炉还原气氛对块矿及混合炉料软熔性能的影响。研究发现,高还原势的氧气高炉条件下,含铁炉料还原度的提高导致其颗粒内部铁相数量增加,低熔点渣相数量减少,块矿的软熔性能与传统高炉条件相比有所改善。同时,通过对软熔过程相关数据及炉料颗粒微观结构的分析,发现氧气高炉条件下,块矿-烧结矿混合炉料在界面上发生了交互作用;由于铁相数量的增加及渣相的减少,不同渣相的接触时间被推迟,接触的渣量也减少,导致相对于传统高炉条件,氧气高炉条件下发生交互作用的温度升高,其作用强度减弱。     

冶炼钒钛矿高炉富氢非等温还原行为及合适富氢率的探讨

高炉富氢是降低高炉能耗与碳排放重要途径,为确定高炉合适富氢率,研究了不同富氢率条件下钒钛矿的软熔滴落过程,并采用历程中断法分析了钒钛烧结矿、球团矿的非等温还原行为。研究结果表明,高炉富氢改善了钒钛矿还原条件,随煤气富氢率的增加,钒钛烧结矿、球团矿的还原度升高,尤其是高温条件下,煤气富氢率对还原的影响更为明显,初渣中FeO含量减少,初渣渣量降低,冶炼钒钛矿高炉富氢后软熔带位置下移,厚度减薄,尤其是透气性最差的熔融区间变窄,透气性增加;由于物理形貌和结构特征的不同,钒钛烧结矿与球团矿的还原速率随富氢率的增加表现出不同的变化趋势,富氢后钒钛烧结矿的还原速率在900～1 000℃达到最大值,而钒钛球团矿的还原速率随温度的增加呈增加趋势。高炉富氢恶化了钒钛矿非等温还原过程的粉化指标,适当减小炉身角可缓解富氢高炉块状带钒钛矿还原粉化现象。当煤气中富氢率以5%幅度增加时对钒钛矿非等温还原和软熔滴落性能的影响是不同的,富氢率由0增加到5%时的影响最大,其次是由5%增加到10%,富氢率超过10%时对钒钛烧矿的还原及软熔滴落行为影响较小,综合考虑还原气体富氢率对钒钛矿非温度还原、软熔滴落性能和软熔带分布的...     

矿焦混装对钒钛矿综合炉料软熔滴落的影响

 为提高高炉冶炼钒钛磁铁矿水平,系统研究了矿焦混装对高炉综合炉料软熔滴落性能和V、Cr在渣铁中迁移规律的影响,并进行了理论分析。试验过程中烧结矿和球团矿所占比例不变。研究表明,矿焦混装对高炉综合炉料的软化区间、熔化区间、滴落率和透气性等软熔滴落性能参数有显著影响。随着混装率提高,软化区间[t40－t4]稍微变宽;熔化区间[tD－tS]逐渐变窄,软熔带变薄且位置下移;熔滴性能总特征值明显减小,综合炉料透气性能显著改善;渣铁滴落率先增加后减少;V、Cr在初铁中的收得率先升高后降低。因此,一定程度的矿焦混装有利于改善钒钛磁铁矿高炉冶炼综合炉料的软熔滴落性能,其混装率以25%为宜。     

烧结矿碱度变化对软熔滴落性能影响的试验研究

介绍了改善烧结矿软熔滴落性能对强化高炉冶炼的重要性,并通过试验系统研究了烧结矿碱度变化对软熔滴落性能的影响。试验结果表明:对于高碱度烧结矿来说,随着碱度升高,开始软化温度、开始熔化温度均呈现下降趋势,滴落温度升高,软熔区间、熔化区间均变宽,初渣熔点升高,整体性能呈现变差趋势。     

钒钛烧结矿与普通烧结矿软熔性能对比研究

在实验室软熔滴落装置中,模拟高炉条件下,对比研究了钒钛烧结矿和普通烧结矿性能指标的差异。研究结果表明:钒钛烧结矿软化开始温度高、软化终了温度低、滴落温度低;钒钛烧结矿压差高,透气性较差。     

钒钛烧结矿高炉冶炼软熔滴落带还原过程模拟研究

在试验室软熔滴落装置中,研究了全钒钛烧结矿、攀钢钒钛烧结矿配8％风云块矿及鞍钢普通烧结矿的软熔滴落性能及还原过程.结果表明:钒钛烧结矿具有较高的软化、熔化及滴落温度,软熔带料柱压差高,滴落困难。该矿还原过程复杂,但因其结构疏松,还原性能比普通鞍钢烧结矿好。钒钛烧结矿配加块矿后,炉料中TiO_2含量降低,软熔滴落性能改善。     

球团矿中MgO含量对炉料熔滴性能的影响

球团矿带入适宜的MgO可以提高炉渣的冶金性能,有利于高炉冶炼。为了探究球团矿MgO含量对高炉炉料性能的影响,在全球团冶炼的条件下,以高炉终渣成分为依据进行配料,利用高温熔滴炉检测球团矿不同w(MgO)时高炉初渣性质、炉料软熔滴落性能的变化情况。试验结果表明,随球团矿w(MgO)升高,初渣中未矿化的MgO明显增多,软化结束温度升高,软化温度区间变宽,炉料软化性能变差。当球团矿w(MgO)大于1.01%后初渣熔点升高,导致熔化特征温度升高,熔化带位置向高温区移动,熔化温度区间变窄,熔化带透气性提高;炉料的软熔带温度区间由229 ℃升高至269 ℃,软熔带增厚,炉料整体透气性变差。由于初渣中w((MgO))随之增加,初渣黏度升高,炉料最大压差和熔滴性能特征值增大。因此,在试验范围内,随球团矿w(MgO)升高,高炉炉料的软熔滴落性能恶化,渣铁分离变差,不利于高炉顺行。     

Study on softening melting characteristics of iron bearing material in oxygen blast furnace

The softening melting characteristics of sinter, pellet and mixed ore in oxygen blast furnace and traditional blast furnace were studied by using load softening and dropping equipment. It is found that, compared with the traditional blast furnace under the softening starting temperature of sinter, pellet, and their mixture decreases, the softening ending temperature increases in oxygen blast furnace atmosphere. Under the condition of oxygen blast furnace, the dropping temperature of sinter decreases, the dropping temperature of pellets and their mixture increases, and dropping zone becomes narrow and even disappears. Through the analysis of the data of the soft melting process, it is found that the mixed ore has a certain interaction effect in the oxygen blast furnace atmosphere, which improves the gas permeability of the charge.     

Softening and Melting Behavior of Ferrous Burden under Simulated Oxygen Blast Furnace Condition

The softening and melting behavior of sinter,pellet and mixed burden was researched through high temperature reaction tests under load simulating traditional blast furnace(T-BF)and oxygen blast furnace(OBF)conditions.The results indicated that compared with T-BF,the softening zone of sinter and pellet became wide,but the melting zone became narrow in OBF.The permeabilities of both sinter and pellet were improved in OBF.Under the condition of OBF,the temperature of softening zone of mixed burden was increased by 63 K,but the temperature of melting zone was decreased by 76 K.Therefore,the permeability of material layer was significantly improved.This was mainly caused by the change of the melting behavior of pellet.In addition,the quality of dripping iron in OBF was much better than that of T-BF.     

Study on the interaction behaviour between lump and sinter under the condition of oxygen blast furnace

This research report describes the influence of the reducing atmosphere of oxygen blast furnace (OBF) and traditional blast furnace (TBF) on the softening and melting behaviour of lump and lump-sinter mixed burdens assessed by using the softening and melting test. The results reveal that in the OBF atmosphere, the softening and melting properties of lump ore is improved compared with that of the TBF, since the development of reduction degree increased the quantity of the iron phase in the burden particle, and decreased the quantity of slag phase with low melting temperature. In addition, the analysis on the microstructure of burden particles revealed that the interaction effect also occurred at the interface between lump and sinter particles in OBF case. Meanwhile, the scanning electron microscope images shows that the interface is still distinguishable when the samples of OBF case reached 60% contraction ratio (1379°C), whereas in the case of TBF, the interface almost disappeared above 40% contraction, and became completely undistinguishable at 60% contraction ratio (1290°C). This illustrates that, under the OBF condition, the starting temperature of interaction is raised, and the effect intensity is weakened.     

不同球团矿和块矿配加条件下炉料冶金性能

 针对铁矿石品种多、质量波动大,导致高炉炉料结构稳定性下降的问题,通过实验室试验,系统研究了含铁矿石的冶金性能以及烧结矿与不同种类天然块矿和球团矿搭配的混合炉料结构高温性能。结果表明,烧结矿的还原性能和熔滴性能优于酸性球团矿和进口块矿,但是低温还原粉化现象十分严重,低温还原粉化指数RDI_{>3.15 mm}仅为70%,哈皮块矿的滴落温度过低,只有1 353 ℃,南非块矿压差过大(6 820 Pa),不利于高炉稳定顺行;里奥球和萨玛科球冶金性能优良,可以适当地提高其比例来弥补烧结产能不足的缺陷;在低烧结比(55%)条件下,不同球团搭配使用时,炉料的软化区间、熔融区间变窄,最大压差Δp_m降低,综合性能得到明显改善。最佳的混合炉料结构为55%烧结矿+20%里奥球+5%萨玛科球+20%哈皮块矿;配加纽混块矿的炉料结构,软熔区间窄,最大压值Δp_m和总特性值S低,软熔滴落性能较好。     

Microstructure evolution during softening and melting process in different reduction degrees

This paper concerns the degree of indirect reduction in a burden rising substantially in an oxygen blast furnace. It studies the pellet, sinter and a mixture of both in different cases. The paper concerns experiments on single particle load softening to investigate the microstructural evolution of different burdens during the softening and melting process. The results of the experiments show that the degree of reduction impacted the softening and melting behaviour. In the case of a low degree of reduction, a slag phase substrate and a myrmekitic iron structure were formed on the periphery area of the molten burden, whereas slag phase substrate and disperse island wüstite structure were formed in the centre area. Both peripheral and central areas had a slag phase substrate and myrmekitic iron texture. The slag–iron distribution had a structure in which the slag phase was cut in the metal iron phase. The content of 2FeO.SiO₂ as a low melting point phase in the slag decreased sharply, and this resulted in the increase in slag–iron separation temperature. The variation of the Ca/Si ratio in the interface between the pellet and the sinter indicated that enhancement of the reduction degree caused the initial temperature of the interaction in the mixed burden to rise and the interaction distance to decrease.     

Softening and Melting Behavior of Mixed Burden for Oxygen Blast Furnace

 The behaviors of mixed burden in the cohesive zone of oxygen blast furnace were studied by softening and melting tests, and the influence of reducing gas and burden basicity on the softening and melting behaviors of mixed burden was also investigated. The results indicated that the softening range became wide, however, the melting range narrowed sharply in the atmosphere of oxygen blast furnace. The permeability of burden in the oxygen blast furnace was obviously improved comparing with the conventional blast furnace. In addition, the content of sulphur in the dripping iron of oxygen blast furnace was much lower than that of conventional blast furnace, however, the content of carbon increased. An optimum basicity of burden, which could lead to the appearance of the narrower melting range and better permeability of burden, was obtained in the atmosphere of oxygen blast furnace.     

软熔过程中烧结矿和块矿的交互作用

 为更好地明晰块矿的软熔行为并优化其在高炉内的使用,以烧结矿和澳大利亚纽曼混合块矿为研究对象,分别就两者在软熔过程中的物理和化学交互作用进行了试验研究。通过使用中子CT扫描软熔试验试样, 发现1 450 ℃时烧结矿与纽曼混合块矿的混合炉料孔隙度要高于两者单一炉料,即两者间存在着物理交互作用;通过采用扫描电镜和电子探针分析发现,1 200～1 300 ℃温度范围内烧结矿中钙和镁扩散到了块矿中,两者发生了明显的化学交互作用。在物理和化学交互共同作用下,配加约20%纽曼混合块矿的混合炉料软熔行为得到了明显改善,且其性能相似或略好于同碱度的单一烧结矿炉料,这表明块矿和烧结矿混合后能在高炉内形成温度区间更窄、位置更低、透气性更好的软熔带。