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.     

Iron Ore Sintering: Quality Indices

Sinter plants process a mixture of iron ore fines, recycled ironmaking products, slag-forming agents and solid fuel (coke) with the finality of obtaining a product with the suitable characteristics (thermal, mechanical, physical, and chemical) for being fed to the blast furnace. With this objective a series of parameters are defined, including the nature and composition of each component of the mixture, and the conditions of the sintering process. Sinter characterization includes chemical and granulometric analysis, determination of the mineral phases in its structure, apart from a series of quality indices that includes reducibility, low temperature degradation, reduction degradation and Tumbler. Operated sinter plants with the maximum productivity are also important with the purpose of obtaining a sinter with uniform composition and quality for facilitating the steady state operation of the blast furnace.     

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。     

氧化铝对铁矿石烧结质量和生产率的影响(英文)

烧结矿是现代高炉生产的主要含铁原料。合理控制入炉烧结矿的理化性能与冶金性能对高炉生产和稳定操作是很必要的。铁矿粉是烧结矿的主要原料,其化学成分和烧结料层内的热量条件在烧结过程中起着重要的作用。化学成分等参数也决定着烧结矿矿相结构和质量。由于含氧化铝原料的低反应性及其液相的高粘性,因此在人们的预料中高铝矿石对烧结矿结构组成的影响并不好。烧结混合料中的氧化铝在同化过程中需要消耗大量热量,延迟烧结过程。在确保高炉渣的流动性方面,氧化铝也需要消耗较大热量。不论是烧结还是高炉的生产实绩均表明,氧化铝是有害的。一般而言,高含铁量与低脉石的印度矿与其他矿石的不同特点就是氧化铝含量高。由于高品味铁矿石的消耗殆尽,使用可利用的烧结原料成为生产必需。因此,必须要掌握氧化铝的作用及其对烧结矿质量和生产过程的影响。实验室完成了不同氧化铝含量水平(2.00%～5.46%)的实验,可从中了解氧化铝在烧结矿矿物学、生产率、物理性能和冶金性能方面的影响。随着烧结矿中氧化铝含量的增加,残存赤铁矿、复合铁酸钙(SFCA)和孔隙率增加,而磁铁矿和硅酸盐比例下降。烧结生产率和烧结矿转鼓强度(TI)随着氧化铝含量上升而下降,反映烧结矿冶金性能的诸如低温还原粉化率(RDI)和还原率(RI)提高。     

碱度对钒钛烧结矿强度和烧结过程的影响

在新的配矿条件下，研究了碱度对承钢钒钛磁铁烧结矿的强度、矿物结构和烧结过程的影响。结果表明：在大量使用澳矿时，综合考虑烧结矿碱度对承钢烧结过程、高炉炉料结构和高炉冶炼过程的影响，烧结矿碱度控制在1．9左右比较适宜。     

改善混匀料性能 降低烧结生产波动

烧结混匀料的性能对烧结矿产质量起着非常重要的作用,并且直接关系高炉冶炼的稳定顺行。混匀料烧结性能如果波动较大,对烧结矿产质量水平的提高将带来负面影响。本文主要介绍一些降低烧结混匀料指标波动、提高烧结混匀料综合合格率、稳定烧结生产的方法,为高炉稳定顺行创造良好的原料条件。     

济钢400m^2烧结机向2、3号1750m^3高炉供料系统优化

济钢第二炼铁厂400烧结机投产后,主要向3200 m^3高炉提供烧结矿,富余的烧结矿供给2、3号1750 m^3高炉,由于400 m^2烧结机工程比3200 m^3高炉投产时间早,为采用最佳的高炉生产模式组织生产,需要对400 m^2烧结机向2、3号1750 m^3高炉的供料系统进行优化。     

烧结配加高炉除灰的工业试验

介绍了申钢对烧结配加高炉除尘进行的工业实践。通过实践证明高炉除尘灰配加在烧结生产中是可利用的。并重点阐述了烧结过程中配加高炉除尘灰的技术以及过程中的参数控制。针对过程中发生的问题制定了相应的工艺措施，为生产配加高炉除尘灰的烧结矿提供了有效的依据，并核算了对应的经济效益。     

360m^2烧结机提高澳矿配比的生产实践

介绍了烧结生产上随澳矿配比逐渐增加,烧结的转鼓强度与烧结操作都有不同程度的变化,摸索不同的澳矿配比对烧结及高炉生产所产生的影响,并相应采取措施进行改进。     

Effect of polydisperse sintering ore on the pelletizing of fine concentrates

An addition of the polydisperse Yakovlevo deposit sintering ore on the efficiency of pelletizing and, hence, the gas permeability of a sintering mixture containing fine concentrates is studied. This sintering ore is found to have unique properties, which make it possible to increase the iron content in a sinter and to improve the gas permeability of a sintering mixture significantly (by a factor of 2–4). As a result, the sintering machine capacity can be substantially increased, the strength of the sinter can be increased at a lower fuel flow rate and lower lime consumption, and the blast furnace capacity can be substantially improved at lower consumption of expensive coke. Therefore, this version of using the Yakovlevo deposit sintering ore has a high economic efficiency.     

库粉在烧结生产中的应用

库粉具有含铁品位高、含SiO2和Al2O3低、价格低等特点，为了充分利用库粉，针对其粘性差、含结晶水影响烧结料层透气性的问题，进行了优化配料结构和烧结工艺参数的生产试验。结果表明，在保证烧结矿产量、质量的基础上，可以配加12％库粉，既满足了高炉的需要，又可降低原料成本。     

Design and optimisation of charging ingredients and structure in an ironmaking system (Part II)

In order to maximise the reduction of pig iron cost in an ironmaking process, and at the same time ensure the output and quality of the pig iron, a design and optimisation system for the charging ingredients and structure in an ironmaking system was established using metallurgical theory. The system includes six modules, namely, sinter metallurgical performance testing and analysis, sintering burdening design, sinter component and property prediction, blast furnace burdening design, blast furnace batching calculation and ironmaking system burden optimisation. Based on actual production, testing and material balance theory, the system integrated these modules on VB and MATLAB using a series of intelligent algorithms, such as the BP neural network, multiple objective linear programming, genetic algorithms and so on. As a result, the optimum burden composition and structure of the sinter and blast furnace that satisfied all the constraint conditions could be obtained. Standing as a pinnacle of the global ironmaking production, the system can design and optimise not only the sintering burden, but also the blast furnace burden. Compared with the traditional production testing and hand calculation in the ironmaking system, the project can greatly reduce the production risk and greatly increase the calculation accuracy. Industrial application shows that the system is especially beneficial to reduce the ironmaking cost and at the same time ensure the output and quality.     

承德钒钛磁铁矿低碱度烧结试验研究

通过烧结杯试验研究了承德钒钛磁铁矿的低碱度烧结过程和烧结矿质量,探讨了低碱度钒钛烧结矿替代球团的可行性。结果表明：与高碱度钒钛烧结矿相比,低碱度钒钛烧结矿的成品率高、强度好、低温还原粉化性能好,可以满足高炉冶炼要求。但其垂直烧结速度慢,w（FeO）高。碱度控制在0.8,配碳量控制在3.4%～3.6%,配加20%的澳矿粉可以取得较好效果。     

w(MgO)对含钒、钛烧结矿强度和烧结过程的影响

研究了w(MgO)对承钢含钒、钛烧结矿的矿物组成、矿物结构、烧结矿强度和烧结过程的影响,发现提高烧结矿中的w(MgO)对于提高承钢高碱度烧结矿的产量和改善烧结矿的质量都是十分不利的.考虑到高炉冶炼的需要,承钢烧结矿中的w(MgO)应控制在2.0 %左右.     

山东省铁矿石来（进）料加工回顾与展望

介绍了山东省铁矿石来料加工的历史,指出进口铁矿石的引入为山东省高炉冶炼实现“酸性球团矿(或块矿) 高碱度高品位烧结矿”的合理炉料结构奠定了基础,从而提高了高炉综合经济技术指标;并探讨了未来山东省进口铁矿石的发展方向。     

莱钢降低烧结矿返矿率实践与创新

莱芜分公司炼铁厂4#265 m2烧结机投产于2005年,烧结矿占高炉炉料结构70%⁸0%,近几年高炉产能不断提升,为了满足高炉生产需求,4#265 m2烧结机通过一系列的设备改造、工艺改进,使烧结矿返矿率由24%降低到21%,烧结矿产量由单班2 550 t提高到2 650 t,满足了高炉生产需求。     

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.     

烧结矿低温还原粉化影响因素研究进展

烧结矿入炉后,会在高炉上部发生低温还原粉化现象,严重时会影响高炉料柱透气性,破坏高炉顺行.为了改善烧结矿的这一性能,揭示烧结矿粉化机制,归纳了化学成分、添加物、微观结构、外部还原气氛和烧结工艺等对烧结矿低温还原粉化的影响,分析了改善烧结矿低温还原粉化性能的方法,为粉化机制研究、烧结配矿提供参考.     

Influence of magnesia on sintering characteristics of iron ore

Abstract

The MgO in blast furnace slag provides an optimum condition in terms of both good flowability and desulphurisation. The mode of its addition to the blast furnace changed from, initially, as raw flux in the form of dolomite, to via sinter, with the argument that raw flux demands energy for its decomposition inside the blast furnace. Thus, the decomposition reaction was diverted from the blast furnace to the sintering bed, and the energy source for decomposition was changed from costly blast furnace coke to a relatively cheap coke breeze. Now olivine/dunite/serpentine is being used as a source of MgO, where energy for decomposition is not required; this also provides a source of SiO₂, which eliminates need for the addition of quartzite. The effect of MgO on blast furnace slag is fairly well established, but its effect on sintering and sinter quality is unclear. Operating results of the sinter plants show that, with an increase of MgO, the sintering rate, the fuel rate, and sinter strength and reducibility deteriorate; however, high temperature properties such as the reduction degradation index and the softening-melting characteristics of the sinter improve. The present work attempts to establish this influence on the sintermaking process and sinter quality with the help of operating plant data.     

高炉配加高钛型球团矿的工业试验及应用

通过高炉配加10%～40%高钛型球团矿替代混合球团矿工业试验,探索出了高钛型球团矿对烧结和高炉生产的影响。工业试验表明,高炉配加高钛型球团矿后,由于烧结配料中钒钛磁铁矿用量减少,烧结矿转鼓提高1.18%,返矿率降低1.33%,高炉煤气流分布更加合理,高炉利用系数提高0.11t/（m3.d）,煤比增加22kg/t,焦比降低18kg/t。推广应用期间,高炉稳定顺行,炉缸活跃,利用系数提高0.141t/（m3.d）,高炉各项指标得到明显优化。