技术信息

由鞍钢钢研所提出的双球烧结工艺研究,历时5年,取得重大突破。1989年3月26日在鞍山通过了鉴定。双球烧结工艺是针对细赤铁精矿烧结存在的问题而提出的。该工艺将细精矿分别制成两种碱度的小球料进行烧结,显著改善了烧结料层的透气性;由于熔融特性的变化,形成以铁酸钙为主的粘结相,使烧结矿的冶金性能也显著改善。     

赤铁精粉配比对烧结矿强度的影响

 铁精粉具有铁品位高、脉石矿物含量及有害元素少、价格较低等优点，但由于其粒度过细，会对烧结生产产生不良影响，进而导致其使用受到限制。为了明确铁矿烧结过程中赤铁精粉配比对烧结矿强度的影响规律，采用微型烧结法研究了赤铁精粉配比对烧结液相流动性及其固结强度的影响规律，并在此基础上进一步探究了优化石灰石粒度对烧结矿强度的影响规律，最终为高效使用赤铁精粉提供理论基础。研究结果表明，随着赤铁精粉配比的增大，烧结体固结强度呈现先略微降低，而后在配比为15%时大幅下降（相对于配比10%铁精粉来说固结强度降低了16%），这是由于随着赤铁精粉配比的增大，黏附粉的偏析碱度降低，进而使得黏附粉的液相流动性减小，最终导致烧结矿强度降低。然而，减小石灰石粒度，可以有效改善烧结液相流动性，进而提高烧结矿强度。     

细粒MINAS RIO赤铁精矿烧结行为及其强化研究

针对MINAS RIO赤铁精矿粒度细、制粒性能差,在烧结料中配比不能太高的问题,开展了分流造球预成型强化制粒烧结工艺研究。结果表明,该工艺能显著改善混合料的透气性,降低焦粉配比,提高烧结料层氧位,生成更多的铁酸钙粘结相,形成大小适中的圆孔,从而改善烧结矿强度和还原性。     

烧结矿成矿特性研究

通过对某198 m~2烧结机料层温度以及烧结矿分区质量的测试研究了烧结矿的成矿特性。烧结料层温度测试结果表明:上层烧结矿燃烧带持续时间短、最高温度低,其燃烧带的热流强度(CTI)仅不足下层的10%,说明烧结料层下层热量充沛、液相充足,上层热量不足、不利于液相生成。烧结矿质量分区检测结果表明:烧结矿质量偏析主要集中在垂直方向上,表现为表层烧结矿强度低、抗摔性能和粒度组成差;下层烧结矿强度高、抗摔性能和粒度组成好;30%以上的烧结返矿集中在占总烧结矿料层厚度16.7%的表层烧结矿。基于此,增加表层矿热量、提高表层烧结矿质量是改善烧结矿质量的重要方向之一,热风烧结和厚料层烧结等技术是可行的技术手段。另外,进一步改善偏析布料效果仍需要深入研究。     

焦炉煤气强化烧结技术研究

在烧结料面喷入一定量的可燃气体,在烧结负压作用下,可燃气体被抽入烧结料层并在料层中的燃烧层上部高温段燃烧放热,从而拓宽了烧结燃烧层;同时,由于减少了固体燃料配比,使得烧结最高温度降低,有利于复合铁酸钙的生成,从而改善烧结矿质量。试验重点研究了喷加10 min和15 min条件下不同热量补偿比例对烧结指标的影响。结果表明:喷入焦炉煤气后,烧结矿质量和冶金性能得到改善,微观结构趋于合理。     

焦炉煤气强化烧结技术研究

在烧结料面喷入一定量的可燃气体,在烧结负压作用下,可燃气体被抽入烧结料层并在料层中的燃烧层上部高温段燃烧放热,从而拓宽了烧结燃烧层;同时,由于减少了固体燃料配比,使得烧结最高温度降低,有利于复合铁酸钙的生成,从而改善烧结矿质量。试验重点研究了喷加10 min和15 min条件下不同热量补偿比例对烧结指标的影响。结果表明,喷入焦炉煤气后,烧结矿质量和冶金性能得到改善,微观结构趋于合理。     

厚料层烧结实验研究

本文针对厚料层烧结的特点匹配相适宜的工艺参数,在烧结实验室通过烧结料层厚度调整、水分调整、焦粉配比调整等工艺参数的调整,来摸索与厚料层烧结相适宜的工艺参数。实验结果表明,适宜的混匀料水分为6.3%—6.6%;适宜的焦粉配比为3.8%～4.1%;同时提高烧结料层厚度,对于改善烧结矿质量及降低固体燃料消耗具有积极的促进作用。     

超厚料层均质烧结技术的研究与应用

提高料层厚度能够充分利用烧结料层的自动蓄热作用,从而降低烧结工序的固体燃料消耗,因此厚料层烧结一直是烧结生产的主要发展方向之一。通过对烧结料层透气性进行理论分析,开展改善混匀料堆积效果、优化烧结布料时混合料粒度分布的横向偏析和纵向偏析等技术研究;同时通过优化操作参数、治理漏风和提高料温等措施,将首钢京唐公司550 m~2烧结机的料层厚度提高到910 mm以上。结果表明:烧结矿中铁酸钙质量分数提高了3.67%、返矿率降低了2.36%、固体燃料消耗降低了1.93 kg/t-s,达到改善烧结矿产、质量和节能减排的目的。     

超厚料层烧结过程固体燃料的分布规律

铁矿烧结以固体燃料作为主要热量来源,其热量高效利用对于烧结节能减排具有重要意义。本文聚焦超厚料层烧结条件下固体燃料在料层中的分布特性,系统解析其在泥辊宽度方向以及料层高度方向的分布规律。结果表明：沿泥辊宽度方向,整体混合料粒度中间偏细、两侧略粗,而含碳量则为中间偏高、两侧略低;布料之后,台车宽度方向混合料粒度组成和含碳量与泥辊对应位置处的混合料规律一致;在料层高度方向上,自上而下混合料粒度整体呈增大趋势,含碳量则逐渐减小,由于泥辊与九辊布料的偏析程度有限,在部分高度处粒度与含碳量会出现波动;利用台车高度方向混合料的粒度组成和泥辊下料处各粒级的含碳量计算出沿料层高度方向的燃料分布,与实际规律基本一致。研究结果可为超厚料层烧结过程固体燃料的优化分布提供指导。     

改善厚料层烧结热态透气性的研究

针对厚料层烧结过程中,因料层自动蓄热导致下部燃烧带过宽,热态透气性下降,影响垂直烧结速度,进而影响烧结矿产量的问题,通过实验研究分析了烧结过程中高温带宽度、温度分布特征及规律、以及燃料迁移、不同粒度燃料燃烧效率等对热态透气性的影响;提出了优化燃料粒度、改善燃料燃烧性、采用燃料分加结合熔剂分加等改善烧结过程热态透气性的技...     

配加南非粉对首钢烧结矿产质量影响的研究

为了拓宽首钢烧结用料,达到优化烧结原料结构和降低能耗的目的,根据南非矿粉的物相和理化特性,按不同比例配加南非矿粉进行了烧结杯试验和工业试验,得出了适宜的工艺参数和生产指标,为首钢烧结厂进一步优化配料,改善烧结矿质量,降低烧结能耗提供了依据.     

流化状态下附碳赤铁矿粉物质形态的研究

对流化状态下赤锋铁矿粉附碳后的物相组合,显微结构,化学组成及矿粉被还原程度进行研究。通过矿相分析、电子显微镜分析、Ｘ射线衍射洋学分析,发现流化状态下的赤铁矿粉随附碳时间地的延,颗粒结构的变疏松多孔,还原程度加深,颗粒表面形成的钓饵笏很少,有利于防止粘结。     

Innovative Development on Agglomeration of Iron Ore Fines and Iron Oxide Wastes

In steel industry and in mines, a significant amount of ultra-fines waste iron oxides and iron ore fines is generated. Utilizations of these fines are required to reduce the environmental hazards and conserve the natural resources. Some of these fines are normally used in sintering practice. However, sintering has a limitation of accepting ultra-fines materials. Pelletizing can use ultra-fine iron oxides. However, suitable technology is required for preparation of good quality pellets. Some of the fines, viz. blast furnace (BF) flue dust, Linz Donawitz (LD) converter sludge etc., are not suitable due to their high alkali and Zn content. Some other material like slime is not considered to be suitable in normal pelletizing practice, because of its high alumina and silica content and excessively fine size. On the other hand mill scale and blue dust have poor green bonding property. Therefore, suitable technologies are required to be developed for their utilization/recycling. This paper discusses the various technologies developed such as (i) developing flux for basic oxygen steelmaking process, (ii) improved pelletizing practice for better reducibility, lower reduction degradation and replacing bentonite binder, and (iii) special quality sinters for improving micro-fines utilization. These technologies may have very good application potential.     

近年来济钢炼铁系统的技术进步

面对钢铁行业严峻的市场形势,济钢以铁前系统结构优化、降低生铁成本为核心,围绕经济料生产模式开发出了低品质矿烧结及高炉综合冶炼技术.同时,通过优化烧结燃料结构,降低固体燃耗;优化烧结熔剂结构,减少高炉辅料用量;以及生产酸性烧结矿等措施,大大降低了生铁成本,获得了较好的经济效益.     

降低自循环返矿率

分析了影响烧结自循环返矿率的因素.采取了稳定原料结构、强化制粒造球、提高料层厚度、实现低碳、低水烧结、提高职工综合素质、加强工艺操作水平、适量配加外矿的措施,使烧结返矿率从2012年的25.47％降到了2013年7月份的18.22％,从而降低了生产成本,满足了炼铁生产需要,提高了企业的经济效益.     

鞍钢鲅鱼圈烧结配矿试验研究与工业应用

为保证鞍钢鲅鱼圈高炉顺利开工,根据鲅鱼圈的现有运输条件和铁粉矿资源,进行了高比例赤铁粉矿烧结的配矿研究。通过对各种配矿方案(包括全部采用赤铁粉矿)进行烧结杯试验,并对烧结矿的高温冶金性能、矿物组成和微观结构等进行检测、比对和分析,认为方案1能够满足鲅鱼圈分公司烧结开工的配矿要求。经生产验证,烧结矿合格率、品位、碱度及转鼓强度、利用系数、<5 mm粉末含量等指标维持在3σ~4σ的水平,可以满足大高炉生产需求,保证高炉的稳定顺行。鲅鱼圈烧结和高炉的开工标志着鞍山钢铁集团大比例粉矿烧结时代的开启。     

Structural and morphological changes during reduction of hematite to magnetite and wustite in hydrogen rich reduction gases under fluidised bed conditions

Abstract

During the reduction of iron ore fines structural changes in particles have a significant influence on the rate of reduction. Investigations regarding porosity, specific surface area and mean pore diameters in the reduction of hematite with hydrogen rich reducing gases were performed by mercury porosimetry. Morphological changes were examined by metallographic analyses of polished sections in reflected light. In the magnetite equilibrium phase, significant influence of temperature on structural parameters and sintering effects were found.

For wustite phases, the influence of temperature was less pronounced. For the reduction of hematite to magnetite and magnetite to wustite topochemical phase growth and microporous product layers were observed. In the single step, reduction of hematite to wustite progressive conversion and significant increase in the mean pore diameter were found. The results presented in this work are of high importance for understanding the reaction kinetics of iron ore fines and essential for modelling heterogeneous reactions.     

Influence of Coating Granulation Process on Iron Ore Sinter Quality and Productivity

For better blast furnace performance, there has always been a need for better quality raw materials like sinter, lump ore, and pellets. Among these raw materials the usage of sinter in blast furnace is at higher side compared to other iron bearing materials. As the quality of sinter product improves, its usage in blast furnaces also increases. Iron ore fines are the main source for sinter making. To improve the sinter properties it is necessary to provide good quality of iron ore fines. Due to depletion of high grade iron ore resources, goethite and limonitic ore content in iron ore fines is expected to increase gradually. Usually limonitic and goethite ore are associated with higher alumina and LOI. The conventional sintering process is one of the well established processes for high quality hematite ore. It does not fully respond to the low grade iron ore associated with goethite and limonite. This has led to deterioration in sinter properties and productivity. In recent years the improvement in the quasi‐particle structure with the granulation process is an effective method for improving sinter quality and productivity. To improve the sinter quality and productivity for low grade iron ore fines, different granulation processes like the conventional one, and other two advanced granulation processes like coke breeze, and flux & coke breeze coating granulation were studied in detail by conducting laboratory pot grate sintering experiments. From the test results it was found that sinter productivity, physical and metallurgical properties of the sinter improved with flux & coke breeze coating granulation process compared to conventional and coke breeze coating granulation process. Proper selection of the granulation time is very important to achieve the desired sinter properties. In the present work detailed laboratory experiments have been carried out by varying the coating time from 30s to 110s to study the influence of flux & coke breeze coating granulation time on mineralogy, productivity, physical, and metallurgical properties of sinter. With a coating granulation time of 50s, higher productivity, higher yield, and stronger sinter (higher T.I) with lower RDI and ‐5mm size sinter were achieved.     

基于青钢铁矿粉烧结基础特性的配矿原则探讨

为了给烧结生产优化配矿技术提供基础依据,更好地指导烧结生产,对青钢烧结常用的6种铁矿粉的同化性能、液相生成特性以及烧损和结晶水分解特性等高温基础性能和微观结构进行了研究,且运用评价模型对各铁矿粉进行了评分。结果表明,各铁矿粉的同化温度均未超过1 250℃,可以满足低温烧结的条件,同化性能最好的为铁矿粉E;1 240℃时6种铁矿粉的流动性指数较适宜低温烧结,1 280℃时流动性指数和液相生成量均较高;6种铁矿粉中铁矿粉E的烧损值和结晶水值均处于较高水平,其中铁矿粉F的结晶水含量是6种矿粉中最高的;6种铁矿粉的微观形貌差异较大,铁矿粉C和D表面较光滑,吸水能力差,从制粒的角度上来看,不利于改善制粒效果,而铁矿粉A和B的表面较粗糙,适宜制粒;基于评分的高低将铁矿粉划分为4个等级。