Pelletization Using Humic Substance-based Binder

Humic substances exist widely in lignite coal as high molecular weight organic molecules. They can be used as binders in iron ore pelletization mostly in the form of salt, such as sodium humate and amine humate via extraction from lignite coal. It is worth determining if lignite can be used as a binder without extraction. As a composite binder of organic and inorganics, due to the combustion of humic substance, the strength of fired pellets made with humic substance-based binder decreases slightly. To compensate for this defect and make stronger pellets, cheap calcium bentonite was added into humic substance binder. In this study, a fluxed hematite concentrate was pelletized with various types of binders: lignite plus sodium hydroxide, calcium bentonite activated with modified humic acid (MHA), and MHA binder. Good quality pellets were obtained at optimal parameters. The results show that without extraction procedure, lignite plus sodium hydroxide can be directly used as a binder in pelletization of fluxed hematite; that calcium bentonite improves pellet strength when added to MHA; and that humic substance can partly replace calcium bentonite, reducing the dose of calcium bentonite.     

微波预热新型有机粘结剂球团

 针对有机粘结剂铁矿球团预热球强度低的问题,进行了微波预热球团的试验研究,并与常规管炉预热球团进行了比较,通过光学显微镜和SEM等测试手段,分析了微波预热铁矿球团的成矿机理。试验结果表明,当预热温度为750 ℃时,微波预热球抗压强度为448 N/个,而常规管炉预热球的强度仅为129 N/个。测试分析表明,微波预热球团内部磁铁矿大部分已氧化成赤铁矿,赤铁矿连接成片,并产生了赤铁矿晶粒相互连接,球团矿预热强度得以提高。     

Study on Direct Reduction Characteristics of Iron Ore Coal Mixed Pellets

Ｉｒｏｎｏｒｅｃｏａｌｍｉｘｅｄｐｅｌｌｅｔｓａｒｅｃａｐａｂｌｅｏｆｑｕｉｃｋｌｙｓｅｌｆ ｒｅｄｕｃｔｉｏｎ .Ｉｎｔｈｅｙｅａｒｓｏｆｓｉｘｔｉｅｓ ,ｔｈｅＩｎｍｅｔｃｏｐｒｏｃｅｓｓａｎｄＭｉｄｒｅｘＦａｓｔｍｅｔｐｒｏｃｅｓｓｆｏｒｍａｋｉｎｇｃｏａｌｍｉｘｅｄｐｅｌｌｅｔｓｔｏｄｅａｌｗｉｔｈｔｈｅｓｅｃｏｎｄａｒｙｄｕｓｔｉｎｉｒｏｎａｎｄｓｔｅｅｌｐｌａｎｔｏｒｔｏｐｒｏｄｕｃｅＤＲＩ[1- 3] ｗｅｒｅｄｅｖｅｌ ｏｐｅｄ .Ｒｅｃｅｎｔｌｙ ,ａｌｏｔｏｆｂａｓｉｃｒｅｓｅａｒｃｈｅｓｏ…     

煤种对含煤球团还原速度的影响

研究了在１２２３￣１４７３Ｋ的氮气氛中３种不同挥发分煤粉的粒度、铁精矿粉粒度、温度及碳－氧摩尔比对含煤球团还原速度的影响。发现降低煤粉或铁精矿粉粒度，提高温度或碳－氧摩尔比可提高含煤球团的还原速度，且这４种因素对还原速度的影响程度随煤种挥发分的降低而增大。分别采用以碳气化反应、气相内扩散、界面反应为控制环节而得出的表达含煤球团反应过程的速度方程处理本研究数据，发现３种速度方程（４种表达形式）均能较     

Effects of Binder on the Properties of Iron Ore-Coal Composite Pellets

Large amounts of fines and superfines are generated in Indian iron ore and coal mines due to mechanized mining and mineral dressing operations. Utilization of these fines for extracting metal is of vital concern for resource utilization and pollution control. For agglomeration of these fines, a suitable binder is required. Iron ore-coal composite pellets were prepared by cold bonding. Various binders such as lime, Ca(OH)₂, slaked lime, dextrose, molasses, and sodium polyacrylate (SPA), alone or in combination, were employed for making composite briquettes. The slaked lime–dextrose combination produced the highest strength among the various binders employed for producing composite briquettes and was therefore selected for producing composite pellets for the smelting reduction. In cold bonding, the composite pellets attain the requisite properties due to physico-chemical changes of the binder in ambient conditions. It was possible to obtain a dry strength of more than 300 N per pellet in some cases and more than 200 N per pellet in many trials. Drop strength and shatter index values of composite pellets were also measured. In the present paper an attempt has been made to evaluate the mechanical properties of cold-bonded composite pellets so as to throw some light on the capacity of these pellets to withstand stresses during handling and transportation.     

铁矿球团生球的固结机理及强化途径

通过生球强度破坏机理分析,得出通过对造球原料进行润磨可以有效的增大晶粒间的范德华力,增加生球的机械强度,添加能够通过范德华力、静电力、氢键、化学键、配位键等与铁矿颗粒表面发生作用的粘结剂也可以有效地提高生球的机械强度;提高球团的爆裂温度的有效方法是均衡球团表面气化和内部扩散作用,均衡球团表面气化和内部扩散作用的主要措施是降低球团表面气化的速度,使表面扩散速度减小,添加具有亲水基的有机粘结剂和膨润土可以降低自由水或毛细水的扩散速度,提高球团的爆裂温度;通过对造球原料的改性对生球的强度的提高是有限的,添加有机粘结剂或复合粘结剂强化生球强度仍然是今后发展的一个重要方向。     

鞍钢自产铁精矿合理使用研究

对鞍钢常用4种铁精矿的烧结基础特性进行了试验研究,在此基础上,采用最优试验设计方法,建立了烧结合理配矿的统计模型,给出了烧结获得最佳和最差烧结指标值时的各种矿的定量搭配关系,提出了鞍钢烧结合理配矿方案.优化配矿工业试验结果表明:烧结技术经济指标有不同程度改善,尤其是烧结矿的粒度组成改善、固体燃耗降低;提出并确定了球团配加铁精矿A的优越性,配加铁精矿A后,皂土配比降低8.69%,转鼓强度提高0.35个百分点.     

煤中氢对含碳球团还原的影响

针对含碳球团还原过程中的煤种选择问题,研究了烟煤和无烟煤挥发分中氢对含碳球团还原的作用以及温度、加热速度对氢还原过程的影响。结果表明,含碳球团中煤热解产生的氢对铁氧化物有还原作用。由于煤中挥发分的热解析出温度与氢还原铁氧化物的还原温度不一致,氢在还原初期迅速放出,导致氢的还原作用率低;提高温度和加热速度可提高煤中氢的还原作用率和挥发分的利用率。综合考虑,含碳球团实际生产选择煤种时,应选择反应性好的无烟煤。     

以科技进步为基础、创新求发展——近几年铁矿粉造块技术发展综述

高炉炼铁技术的发展和进步,不仅仅依赖于装备和操作水平的提高,“精料技术”是高炉炼铁发展的基础。本文针对近几年来国内外铁矿粉造块的烧结、球团理论和工艺技术进步及发展进行了系统的总结分析。针对铁矿粉造块工艺所面临的资源、节能减排形势,提出了以科技进步为基础、创新求发展,促进我国铁矿粉造块技术的进步,为高炉炼铁“优质、高产、低耗、环保” 奠定良好的“精料水平”基础技术路线。     

Temperature Distribution of Iron Ore Pellet Bed in Grate

 The temperature distribution of iron ore pellet bed in grate has a significant effect on pellet production and quality control, but the related work is scarce. A well-designed test was successfully carried out by means of tracking measurement and the temperature distribution and variation in pellet layers were obtained. The effects of blast temperature, blast velocity and oxidation reaction on the pellet layer temperature were studied. According to the analysis, the inlet air temperature in the up-draught drying zone (UDD) and blast temperature in the Preheating I (PH I) zone should be raised, and the length of the down-draught drying zone (DDD) should be properly increased.     

Utilization of High Sulfur Raw Materials in Iron Ore Pellets

Pyrite cinder and high sulfur magnetite were used as raw materials to produce iron ore pellets. Good qualities of green balls and fired pellets were obtained from the feed comprising 50% pyrite cinder and 50% high sulfur magnetite concentrate at a small scale. Small-scale tests were proven by pilot-scale tests. The high grade fired pellets, assaying 63.22% Fe, were analyzed, and the compressive strength of fired pellets was over 2500 N/pellet. The fired pellets possessed excellent metallurgical performances, such as reducibility index higher than 67%, reduction swelling index lower than 15% and low temperature reduction degradation index (+ 3.15 mm) higher than 1%, which can be used as the burden for blast furnace.     

链篦机-回转窑铁矿氧化球团焙烧过程的分析

为了降低链-回-环系统球团矿焙烧过程的能耗,对某工业装置进行了平衡测试和分析,得到了流图。分析表明,传热不可逆损和燃烧不可逆损是系统损的主要部分。建立了气体质流量、床层空隙率、床高、球团直径、烟气中氧含量等运行参数与损的关系。结果表明,适当减小气体质流量、床高和球团直径,增大床层空隙率,可以减小损。在其它条件不变的情况下,当烟气中二氧化碳浓度为1.0%～9.0%,将空气消耗系数控制在1.6～2.0,可使损最小。     

酒钢桦树沟铁矿石预选工艺探索

本文就酒钢桦树沟矿矿石预选工艺及国内预选工艺进行对比分析,探索适合酒钢桦树沟矿矿石性质的预选工艺.     

含碳球团的还原熔分行为

通过高温电阻炉对含碳球团还原熔分的行为进行热态模拟研究,考察温度、配碳比、化学成分等因素对球团还原熔分的影响程度.结果表明,温度、配碳比和球团传热方向上的尺寸是控制球团还原熔分的关键;化学成分对还原速率影响不明显,但是通过改变渣的组成可对渣铁熔分起促进或抑制作用.     

Phase and Microstructural Characterization of Iron Ore Pellet and their Relation with Cold Crushing Strength Test

In the production of the pellets, phase identification for specific sintering condition is of prime importance in understanding the basis for the production and the required properties. The application of a methodology involving optical and scanning electron microscope equipped with an EBSD opened a broad possibility to establish a base for the relationship between heat-treated pellet microstructural features and cold crushing strength. The first results from the conjoined application of these techniques show that the cold crushing strength of the pellet increase with the decrease of porosity, the appearance of the fayalite, as well as the presence of magnetite-unoxidized.     

Effect of CaO and CaCO3 on Reduction Rate of Iron Ore Pellets Containing Carbon

Ｔｈｅｃａｒｂｏｎｇａｓｉｆｉｃａｔｉｏｎｈａｓａｇｒｅａｔｅｆｆｅｃｔｏｎｒｅ ｄｕｃｔｉｏｎｂｅｈａｖｉｏｒｏｆｉｒｏｎｏｒｅｐｅｌｌｅｔｓｃｏｎｔａｉｎｉｎｇｃａｒｂｏｎ ,ｅｓｐｅｃｉａｌｌｙｉｎｎｅｕｔｒａｌａｔｍｏｓｐｈｅｒｅ .Ｇｅｎｅｒａｌｓｐｅａｋｉｎｇ ,ａｄｄｉｎｇａｎｙａｄｄｉｔｉｖｅｓ ,ｗｈｉｃｈｃａｎｐｒｏｍｏｔｅｃａｒｂｏｎｇａｓｉ ｆｉｃａｔｉｏｎｒｅａｃｔｉｏｎ ,ｃａｎｅｎｈａｎｃｅｔｈｅｒｅｄｕｃｔｉｏｎｒａｔｅｏｆｉｒｏｎｏｒｅｐｅｌｌｅｔｓｃｏｎｔａｉｎｉｎｇｃａ…     

因民小铁稀铁矿床地质特征及找矿探讨

小铁、稀铁矿床属“稀矿山式”铁铜矿床,走向长1 200-1 500m。向下延深近千米,由海相火山多次喷发形成多旋迴沉积而成,主要容矿岩石为铁质岩、钠质岩。矿床受后期岩浆热液改造,构造影响,使矿源物质再次富集,形成独立矿体;矿体品质与火成岩、凝灰岩、铁质岩有密切关系。矿体形态各异,厚薄变化较大,品质高低不等,受构造控制,具有独立性。本文结合含矿岩性及现有工程,浅谈对残留空白地段进一步探矿的必要性。     

铁矿石高价位背景下的生铁成本控制分析

论述了铁矿石高价位背景下的生铁成本控制,认为生铁的成本控制是一个系统工程,科学采购是直接手 段,生产可控是基础,而科学配矿是桥梁,三者相互联系的同时也相互制约,并提出生铁成本控制的新观点:配矿结 构的确定要根据企业自身的地域特点来制定;利用不同矿种的优势和劣势进行互补搭配,并提高冶炼的技术水平, 减少原料变化对生产和炉况稳定性的影响,实现效益的最大化。     

用X射线荧光光谱仪测定铁矿石及烧结矿成分

提出了用X射线荧光光谱仪快速测定铁矿石及烧结矿主次成分的方法。采用1 2份Li2B4O7与22份LiBO2的混合熔剂、样品与熔剂的稀释比为1∶10的熔融制样方法,精心选择标样,制作分析曲线且分析试样。实验结果表明,此分析方法具有速度快、精度高等优点。     

铁矿石资源产业的未来发展

针对金融危机后全球经济放缓给铁矿石产业前景带来的困境,在介绍情景分析法的基础上,利用情景分析法对国内外铁矿石产业现状及未来发展进行了探讨,对铁矿石产业末来可能出现的4种发展情景即成长缓慢型发展、技术滞涨型发展、竞争充分的发展、寡头垄断发展及对策进行了分析。