含铁炉料间高温交互作用对初渣生成行为的影响

为了考察高炉内烧结矿与块矿间的高温交互反应对其初渣生成行为的影响,本文采用试验研究结合理论计算的方法,研究烧结矿、块矿及其二者混合炉料的初渣生成行为及其初渣特性.结果表明:单种块矿或烧结矿的初渣生成温度区间宽;烧结矿与块矿间的高温交互反应能显著改善块矿的初渣生成行为,并降低其初渣黏度;铁矿石间高温交互反应程度的强弱受其化学成分、还原性能、气孔率等因素的影响.      

烧结矿碱度对综合炉料交互反应的影响

以不同碱度的烧结矿及烧结矿与块矿的混合矿为研究对象,利用荷重软化熔滴装置,考察了烧结矿碱度对综合炉料软熔性能及不同炉料间交互作用的影响。研究发现:随着烧结矿碱度增加,炉料结构中块矿的质量配加比例提高,炉料间的交互作用增强,主要表现为综合炉料软化开始温度及熔融开始温度降低,混合炉料的透气性得到改善。炉料结构的变化使矿物间的交互反应随着烧结矿碱度的提高而增强,进而导致液相成分发生改变,降低了初渣物相熔点,而烧结矿碱度过高时会恶化料柱的透气性。同时通过扫描电子显微镜?能量色散谱仪(SEM?EDS)及X射线衍射(XRD)精修表征整个还原过程烧结矿物相变化,渣相中主要物相为浮氏体和硅酸钙,随着烧结矿碱度增加,在不同断点2CaO·SiO₂的含量呈现降低趋势,表明烧结矿还原过程生成的高熔点物相随之降低,综合炉料的液相生成温度随之降低,炉料间交互作用增强。因此,适当提高烧结矿碱度,提高块矿入炉的质量配比,利于高炉的强化冶炼。      

Simulation of primary-slag melting behavior in the cohesive zone of a blast furnace, considering the effect of Al2O3, Fe t O, and basicity in the sinter ore

The alumina content in the iron ore imported to Japan is increasing year by year, and some problems in blast furnace operation, due to the use of the high-alumina-containing sinter, have already been reported. In order to clarify the mechanism of the harmful effect of alumina on the blast furnace operation, the behavior of the primary melt, which is formed in the sinter at the cohesive zone of the blast furnace, has been simulated by dripping slag through an iron or oxide funnel. The effects of basicity, Al₂O₃, and Fe _t O contents in the five slag systems on the dripping temperature and weight of slag remaining on the funnel have been discussed. It was found that the eutectic melt formed in the sinter would play an important role in the dripping behavior of the slag in the blast furnace through the fine poreosity of the reduced iron and ore particles. Al₂O₃ increased the weight of the slag remaining on the funnel, and its effect became very significant in the acidic and low-Fe _t O-containing slag. It was estimated that the increase of the weight of the slag remaining on the funnel by Al₂O₃ in the ore could result in a harmful effect on the permeability resistance and an indirect reduction rate of the sinter in the blast furnace.     

铁焦与铁矿石混装对高炉初渣形成的影响

 软熔带的形状和位置是影响高炉稳定运行的关键因素之一。研究了综合炉料中混入高反应性铁焦对高炉初成渣形成过程的影响。针对综合炉料进行研究,结果表明,铁焦的加入导致试样的变形开始温度降低,这是由于在较低温度下铁焦即开始与CO2反应,增加了煤气中的CO浓度与平衡浓度的差值,加速了铁矿石的间接还原。铁焦的加入一般使软化结束温度升高、滴落温度下降,使得软熔区间大幅度收窄,表明向铁矿石中混入铁焦能够显著改善高炉料柱的透气性。加入铁焦还使滴落熔铁中的碳含量明显提高。优先考虑对料柱透气性的影响,建议使用加入20%(质量分数)矿粉A的铁焦。     

高比例酸性炉料对高炉操作的影响及应对措施

随着环境保护压力的增加,中国钢铁公司的高炉炉料结构中酸性料(球团和块矿)配比显著提高,尤其在冬季取暖季的时候。但是,各钢铁公司的资源条件不同,采用高比例酸性炉料冶炼时,有的钢铁企业获得较好的生产指标,但也有钢铁企业操作指标不佳或难以实现高比例酸性料操作。基于此,以提高高炉酸性料比例和降低生产成本为目的,分析了高比例酸性料所带来的问题,并提出了应对高比例酸性炉料的技术措施。高比例酸性料对高炉冶炼的影响主要体现在块状带和软熔带。对块状带的影响主要有,粒度的差异导致空隙率降低;堆积性能的差异导致料面难以控制;还原产生的粉末影响高炉块状带的透气性。对软熔带的影响主要有,酸性料自身软熔温度较低;还原度较低导致矿石进入软熔带前FeO含量高,使得软熔带位置上移且变宽;软熔带焦窗长度变长,增加整个焦窗的压力损失。应对高比例酸性炉料的具体措施有,合理选择优质酸性炉料;制备碱性镁质球团;采用合理的布料制度尽量克服球团矿对料面的不利影响;高炉精细化用焦,充分发挥大块焦与小焦丁的特点与功能。能够改善块状带和软熔带透气性的技术措施都可以缓解高比例酸性料对高炉冶炼的不利影响,各生产企业可结合自身的资源情况和炉型特...     

基于不同炼铁工艺的铁矿石低温还原粉化特征

 为改善铁矿石在炉内的低温还原粉化性能以适应多样的炼铁生产条件,以炼铁生产常用的烧结矿、球团矿以及块矿为研究对象,通过控制还原气体成分和温度的方式,考察并比较了不同种类铁矿石在高炉炼铁工艺和COREX非高炉炼铁工艺2种煤气条件下的低温还原粉化行为。试验结果表明,相同的还原气氛和温度条件下,烧结矿、球团矿以及块矿的还原粉化形式、程度有较大差异,而各类铁矿石对煤气性质、温度变化的敏感性也各不相同。这对更为全面地考察和评价不同类型铁矿石的低温还原粉化特征,进而改善铁矿石冶金性能和优化炼铁工艺参数具有一定的实用性和参考价值。     

高炉使用含碳复合炉料的原理

 高炉炼铁正朝着高产、低污染、低能耗的方向发展,为了实现这一目标,包括高炉使用含碳复合炉料等一些革新的炼铁技术已经被提出或实际应用。铁焦、热压含碳球团是将铁矿粉和煤粉按一定比例混合后制成的新型含碳复合炉料。研究结果指出,含碳复合炉料相比于传统的高炉炉料（烧结矿和球团矿）具有高温强度高、还原性能好以及原料适应性强等优势。阐明了高炉使用含碳复合炉料的基本原理,介绍了铁焦制备的工艺流程及应用情况,重点进行了热压含碳球团制备工艺流程、冷态冶金性能、高温冶金性能、高炉使用热压含碳球团等试验研究,最后利用多流体高炉数学模型对高炉使用热压含碳球团操作进行了模拟研究。研究表明,高炉使用一定量的含碳复合炉料可以降低热空区温度,增加产量,降低焦比,高炉热利用效率明显提高,操作性能得到有效改善。     

Al2O3对铁矿烧结球团及高炉冶炼的影响

摘要：随着中国钢铁行业迅猛发展,高品位铁矿石储量减少,进口铁矿石以及国内自产铁矿石中Al2O3含量逐年增加,将会给烧结矿、球团矿生产及高炉冶炼带来一系列不利影响。介绍了不同赋存状态的Al2O3的形成及形貌特征,总结了Al2O3赋存状态改变以及含量增加对烧结矿、球团矿和高炉冶炼的影响规律及机制,Al2O3赋存状态、含量改变会对烧结矿、球团矿的成品矿质量、矿物组成和冶金性能产生影响,同时Al2O3含量的增加会对高炉炉渣的熔化性、黏度和脱硫产生不利影响。基于以上内容,认为可通过改善选矿过程、烧结球团制备过程和高炉冶炼过程3个环节来减少Al2O3对烧结球团、高炉冶炼的影响。     

Influence of Alumina on Iron Ore Sinter Properties and Productivity in the Conventional and Selective Granulation Sintering Process

Iron ore sinter constitutes a major proportion of blast furnace burden. Hence, its quality and consistency have a significant impact on blast furnace performance. Iron ore fines are the main source for sinter, and the chemical composition of the iron ore fines, together with the thermal conditions that blends are subjected to, plays an important role in forming the primary melt during the sintering process and accordingly determines the sinter structure and quality. Therefore, considerable importance has been placed on the chemical composition and consistency of iron ore fines, particularly in terms of alumina content. Due to depletion of high grade iron ore resources, alumina content in the iron ore fines is expected to increase gradually. Ore with higher alumina content is usually expected to be detrimental in forming the sinter matrix, if sintered alone, due to the low reactivity of alumina bearing minerals and the high viscosity of primary melts. The selective granulation process is a new sintering process for high alumina iron ore fines, and can eliminate the adverse effects of ‘hard to sinter’ or ‘unsuitable – for ironmaking’ ores. In the present work laboratory sintering experiments have been carried out with iron ore fines of different alumina level (2.00 to 5.46 mass‐%) to know the influence of alumina on mineralogy, productivity, physical and metallurgical properties of sinter prepared by the conventional and the selective granulation process. With increasing alumina content in sinter of both the conventional and selective granulation process, the fractions of hematite and of silico‐ferrites of calcium and alumina (SFCA) as well as the pore phase increased whereas the magnetite and silicate phases decreased. With increase in alumina content sinter productivity and tumbler index (T.I.) decreased, and metallurgical properties like sinter RDI and reducibility improved. However, sinter of the selective granulation process showed better results compared to the conventional process.     

铁矿粉液相流动性的主要液相生成特征因素解析

烧结矿是我国高炉炼铁的主要原料,烧结矿质量将直接影响高炉冶炼及炼铁工序的经济技术指标.因此,基于铁矿粉的高温特性进行优化配矿从而改善烧结矿的产质量对于炼铁工序节能增效具有十分重要的现实意义.铁矿粉的液相流动性是非常重要的烧结高温特性指标,适宜的液相流动性可以使烧结矿获得较高的固结强度.本文模拟实际烧结黏附粉层中铁矿粉颗粒与钙质熔剂质点的接触状态,采用FastSage热力学计算和微型烧结可视化试验方法研究了固定CaO配比条件下铁矿粉的液相流动性及其主要的热力学液相生成特征影响因素.研究结果表明,采用固定CaO配比与固定碱度的熔剂配加方式下,铁矿粉的液相流动性规律明显不同.铁矿粉的液相生成量是影响其液相流动性的最主要液相生成特征因素,液相生成量越多则铁矿粉的液相流动性指数越大.铁矿粉液相流动性的配合性机制是基于其液相生成量的线性叠加原则.脉石矿物含量将在一定程度上影响铁矿粉的液相流动性,随着SiO₂含量的升高铁矿粉的液相生成量减少,从而导致液相流动性指数显著降低;而Al₂O₃含量增加,液相流动性指数略有升高.      

Fundamental Study on Carbon Composite Iron Ore Hot Briquette Used as Blast Furnace Burden

Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%–50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi‐fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced.     

攀钢冶炼钒钛磁铁矿的炉料结构研究

利用普通高炉冶炼高钛型钒钛磁铁矿有很大的难度。选择合理的炉料结构，控制高含量ＴｉＯ_２的还原，是冶炼该矿石的首要条件。炉料在块状带的还原、高温还原熔化、初渣的生成以及高温带渣铁反应的研究结果和生产实践都表明：提高炉料中ＳｉＯ_２含量，适当配加萤石、铁锰矿或配加部分难还原的矿石都可以改善钒钛烧结矿的冶炼性质。     

改善烧结矿质量降低高炉炼铁燃耗

 通过试验研究了唐山国丰钢铁有限公司（简称国丰）使用的各种进口矿的性能;通过分别配加澳矿、巴西矿和印度矿进行配矿试验,确定了合理的配矿方案。借助试验进一步确定了合理的烧结工艺参数。通过合理控制烧结矿的碱度、MgO含量、Al2O3含量和FeO含量以及采用低温烧结,保持较强的氧化性气氛,烧结矿质量获得明显改善,低温还原粉化率降低,有效降低了高炉炼铁的燃耗。     

莱钢二铁2#高炉生铁降硅实践

莱芜钢铁总厂第二铁厂２＃７５０ｍ３高炉在生产中采取提高烧结矿碱度、配用高品位进口矿、减少入炉粉末、稳定焦炭质量及稳定炉温、适当提高炉渣碱度、提高风温和顶压等一系列措施，使生铁含硅量由０．８４１％降为０．６３７％，生铁一级品率由４２．６７％提高到５４．６１％，高炉综合技术经济指标提高。     

Study of the High Temperature Metallurgical Properties of On-Site Samples with Vanadium–Titanium Magnetite

In China, two typical vanadium–titanium magnetite ores were used as raw materials in iron making. In order to obtain the differences in the high temperature metallurgical properties of these ores, the phase and microstructure of on-site sinter, pellet, slag and laboratorial non-dripped slag were analyzed by XRD and SEM–EDS. The results show that the phases of two typical sinter and pellet have no significant changes, but the microstructures are different. The softening start temperature and softening zone of high chromium vanadium–titanium magnetite (HCVTM) burden are higher than ordinary vanadium–titanium magnetite (VTM) burden. The melting start temperature of HCVTM burden is higher and melting–dripping zone is smaller than VTM burden, which is beneficial to the blast furnace smelting. In addition, the calculation results using Factsage 7.0 are in accord with the experimental results. The primary crystal field of slag of HCVTM is the melilite, and the liquidus temperature is 1409.81 °C; the primary crystal field of slag of VTM is CaTiO₃, and the liquidus temperature is 1418.51 °C.     

Research on optimizing ore matching technology for 550 m~2 sintering machine

The sinter quality is important for its performance in a blast furnace,and optimizing ore matching is a main way to ensure the quality and yield of sinter ore and to reduce the cost of ore matching.The research on optimizing ore matching for a 550 m~2 sintering machine in Shougang Jingtang was carried out in this paper. Firstly,based on the condition of iron ore resourse in Shougang,sintering properties of various ores,especially the high temperature properties were researched,and basic structure of ore matching was determined according to the mutual complementary properties of assimilation and liquid phase fluidity among Australia ore,Brazilian ore and domestic concentrates,that was Australian ore(50%-60%) + Brazilian ore(40%-30%) + domestic concentrates(about 10%).Secondly,9 groups of ore matching schemes were designed and sintering pot tests were carried out,and then the starting scheme of the 550 m~2 sintering machine was obtained:ore from southern Brazil (20%) +ore from northern Brazil(10%) + semi-limonite(20%) + limonite ore(35%) + domestic concentrates (15%).Thirdly,experiment of optimizing parameters of optimizing basicity,lime ratio,water addition and bed depth were carried out,and 9 groups of ore matching schemes were designed.The results showed that parameters fit for Jingtang currently are as follows:binary basicity is 1.9 - 1.95,lime ratio and water addition is 5%and 7.0% respectively;sintering bed should increase to 800 mm gradually.At last,Jingtang sintering plant was put into production successfully and yields stably,with the bed depth of 800 mm and advanced sintering indexes.     

高炉炼铁合理配矿研究

2003年中国的生铁产量超过2亿t,作为炼铁原料的国产铁精矿和进口铁矿几乎各占一半;国产铁精矿是细粒度的磁选精矿,进口铁矿则以粉状赤铁矿为主.如何合理配矿,成为当前必须认真研究的课题.回顾了我国炼铁工作者贯彻"精料"方针取得的成就,并就国内外铁矿资源的状况、特点及合理配矿进行探讨.     

莱钢高炉解剖软熔带含铁炉料特性分析

基于莱钢2007年120 m3生产高炉科学解剖研究内容,系统分析了含铁炉料在软熔带位置物化属性。结果表明,高炉软熔带呈不规则倒V形分布,软熔层矿石还原度由低温侧向高温侧逐渐增加,其中烧结矿的还原度由40%~70%增加至80%~95%,球团矿的还原度由40%~50%增加至70%。软熔层低温侧烧结矿金属化率为20%~45%,球团矿的金属化率为10%~20%,在高温侧烧结矿的金属化率为70%~95%,球团矿的金属化率约为50%~70%。含铁炉料在软熔带区域发生了剧烈的还原反应,其中烧结矿金属化率增加的幅度大于球团矿的主要原因为烧结矿的还原性好于球团矿的还原性。矿相分析表明软熔带中球团矿已没有Fe₂O₃、Fe₃O₄存在,铁主要以FeO和金属铁存在,在软熔带区域存在被还原生成中空的铁壳球团矿。     

Iron Ore Sintering: Process

Sintering is a thermal agglomeration process that is applied to a mixture of iron ore fines, recycled ironmaking products, fluxes, slag-forming agents, and solid fuel (coke). The purpose of the sintering process is manufacturing a product with the suitable characteristics (thermal, mechanical, physical and chemical) to be fed to the blast furnace. The process has been widely studied and researched in the iron and steelmaking industry to know the best parameters that allow one to obtain the best sinter quality. The present article reviews the sintering process that the mixture follows, once granulated, when it is loaded onto the sinter strand. There, the sinter mixture is partially melted at a temperature between 1300-1480°C and undergoes a series of reactions that forms the sinter cake to be loaded into the blast furnace to produce pig iron.