含锌粉尘有机粘结剂团块干燥行为及热态失稳机制

针对含锌粉尘压团工艺粘结剂耗量大、成本高，团块热稳定性差等问题，基于现场物料及配矿方案，通过动态干燥试验，研究了干燥参数对含锌粉尘干团块强度和干燥粉末量影响规律，并对含锌粉尘有机粘结剂团块热态失稳机制进行了探讨。试验结果表明，对以淀粉为粘结剂制备的含锌粉尘生团块，提高干燥风温和风速、延长干燥时间和增加料层高度均会降低干团块强度、增加干燥粉末量。主要原因是：有机粘结剂热稳定性差，高温易热解；含锌粉尘粒度细而分布窄，不利于团块内形成较合理的毛细管半径，也限制了颗粒间相互咬合和粘结力发展；部分高钙型含锌粉尘游离氧化钙含量高，易水化引起团块体积膨胀。生产中可通过开发和使用高热稳定性、低成本复合粘结剂，将含锌粉尘与粒度较粗、粒级较宽的原料优化配矿及对高钙型含锌粉尘进行提前消解等措施，以改善含锌粉尘团块性能。     

利用钢渣制备造渣剂的成型实验研究

在添加有机粘结剂的条件下采用冷压团成型工艺进行了钢渣制备造渣剂的成型实验研究,考察了粘结剂用量,配水量和成型压力对压团力学性能的影响,当粘结剂用量为0.25%～0.30%,配水量为12%,成型压力为50 kN时,制得的压团干、湿落下强度都超过10次/球,抗压强度在1 kN/球以上,能够满足工业生产对造渣剂强度的要求.制备的造渣剂同时具有熔点低、化渣快、脱除钢中有害物质能力强的特点,在冶金性能上满足炼钢用造渣剂的要求.     

合理利用矿山资源的设想

介绍了如下的一些设想:用含银粗铅研制低锡焊料,用炼钢生铁冶炼耐磨高砷钢,用富锰碴生产锰铁合金,用粉锰矿加粘结剂压团造块工艺,古代冶炼遗弃炉渣的再利用,二次利用尾矿回收和逐步开发有色矿。     

铬粉矿冷压球团的研究

针对铁合金行业在铬粉矿冷压球团生产中存在的问题,进行了探索性研究.在实验室条件下,研究了新型含镁粘结剂对铬粉矿冷压球团常温、高温抗压强度影响,并采用电镜扫描分析了铬粉矿使用新型含镁粘结剂的固结机理.研究结果表明,含镁粘结剂的加入量为5%时,冷压球团的高温强度最高可达到425 N,可满足矿热炉正常冶炼需要;低熔点的钙化合...     

石灰在团矿中的作用机理研究

本文分析了石灰在团矿中的作用机遇，比较了石灰同其他粘结剂在制团中的应用效果，从而指出有使用石灰存在的问题和改进措施以及开发多功能有机粘结剂的新趋势。     

碱度对白云鄂博铁精矿压团矿抗压强度的影响

发展熔剂球团矿是当前炼铁原料工艺技术发展的方向和热点之一,球团矿的碱度不同,其理化性质及冶金性能也不同。通过分析不同碱度的白云鄂博铁精矿压团矿矿相结构的变化规律,探究碱度对白云鄂博铁精矿压团矿抗压强度的影响规律。结果表明,随着碱度的升高,压团矿的抗压强度先增加后降低,液相量的增加使得孔隙率降低,压团强度升高,但过多的液相会破坏赤铁矿的整体性结构,渣相强度低于赤铁矿强度,压团的强度逐渐降低。     

锰矿高炉除尘灰的利用

对用湘潭锰矿锰铁高炉的除尘灰，生产冷固结团块作为锰铁高炉的原料进行了试验，研究出固结压团优化工艺条件，结果表明：选用高分子表面活性剂作粘结剂，生产出的冷固结团块具有良好的机械强度，其耐湿性和热稳定性好；同时，添加尾泥能提高团块锰品位。     

提高有机粘结剂氧化球团矿强度的措施

针对有机粘结剂在我国氧化球团生产应用中存在的预热焙烧球强度低、无法满足我国生产要求的问题,进行了提高有机粘结剂氧化球团矿强度的研究.试验结果表明,润磨、加入添加剂能有效提高球团强度.有机粘结剂球团预热和焙烧强度分别为175 N/个和1 494 N/个,润磨能使其提高到571 N/个和 534 N/个,加入添加剂能使其提高到448 N/个和2 406 N/个.通过应用强化措施,在较低的有机粘结剂添加量下,球团即可达到膨润土球团的强度,且提高效益0.1元/t,实现了有机粘结剂替代膨润土、提高球团矿铁品位、提高经济效益的目的.     

复合粘结剂对球团高温固结的影响及机理

膨润土是球团矿生产过程中的主要粘结剂,能显著改善原料成球性、提升球团质量,但较高的SiO₂和Al₂O₃含量会造成炼铁生产渣量增加.添加少量有机粘结剂替代部分膨润土已成为改善球团性能的必要手段.本文考察了有机粘结剂P替代部分膨润土对球团高温强度的影响,结合激光闪射法和热重法(TG)研究了有机粘结剂对磁铁矿球团内部结构及传热、传质的影响.结果表明,复合粘结剂可以替代部分膨润土,适量有机组分的增加有利于预热球、焙烧球强度的提升和球团的氧化.主要原因是有机粘结剂P经过高温后热解,并在球团内部形成适量孔隙,球团热传导系数降低,内部升温梯度减缓,避免了球团表层因过快氧化结晶而形成致密的氧化层.同时,细小的孔隙有利于氧气进入球团内部,促进Fe₃O₄氧化成Fe₂O₃,氧化分数f_TGA随着有机粘结剂P的添加而逐渐升高,由90.80%提至92.17%.     

润式棒磨机的生产实践

竖罐蒸留法炼锌的一个很重要环节就是制团。团矿的制备是将焙砂、还原用煤粉、蒸留过程的返料(主要是蓝粉和焦结粉)按一定比例混合,再加上粘结剂(纸浆废液)经混合、磨细碾压最后制成重约500克的团矿。在团矿制备过程中不仅起到了物料混合均匀的作用,同时也使物料粒度变细,扩大相互间的接触面积。我厂以前制团采用的流程是:球磨机→碾磨机→压密机→制团机(以下称为流程I,图l),该流程在我厂已沿用了四十余年。     

ABSTRACTS--From the Journal of Iron and Steel Research (in Chinese)1999,11(4)-1999,11(6)

EffectofUPConthePropertiesofHighTitanium-BearingSlagofBlastFurnaceZHUZi-zong,ZhangBing-huai,QiuGui-bao(ChongqingUniversity)Abstract:ExperimentswerecarriedouttoclarifytheeffectofUPContheforminganddroppingofhightitanium-bearingslagduringsmeltingsefstromiteinblastfurnacebysimulatingdroppingzoneofblastfurnaceinahightemperatureoven.Followingresultswereobtained:1TiCandTiNformedbyreducingTiO2withUPCeasilyadherecokesurface,whichchangestheinterfacepropertiesofslag-cokeandisfavorabletothedr…     

Application of Modified Humic Acid (MHA) Binder in the Pelletizing Of Fluxed Hematite Concentrate

Modified humic acid (MHA) binder consists of high molecular weight organic molecules and inorganic part. It is extracted from lignite coal with sodium hydroxide and used in pelletization of iron ore concentrates. Our previous study shows that MHA binder is also a potential binder instead of bentonite for pelletizing of fluxed hematite. For evaluating the use of MHA binder in pelletization of fluxed hematite, pelletizing tests were conducted to optimize parameters, such as dose, firing temperature and time. The results show that the qualities of green/dried balls with 0.6 wt% MHA binder are equal to or even better than that of 0.66 wt% bentonite pellets, and that both are much higher than the minimum requirements of the pellets’ strengths. The compression strength of fired pellets also suggested that MHA binder is promising to completely replace bentonite in pelletizing of fluxed hematite concentrate. However, the abrasion rate of the fired pellets with MHA binder is slightly higher than that of bentonite pellets.     

新型黏结剂强化冷固结球团的作用机理

 黏结剂在冷固结球团中必不可少,目前广泛使用的冷固结球团有机、无机黏结剂如CMC、膨润土和水泥等均会在高温下失效,导致球团高温强度严重下降,因此,寻找一种高温强度良好的黏结剂是目前需要解决的问题。采用新型黏结剂制备冷固结球团,通过XRD和SEM-EDS等对新型黏结剂球团制备原料及球团性能特征进行分析,同时探讨黏结剂对球团冷态抗压强度及高温强度的影响及其作用机理。试验结果表明,黏结剂以流动状态存在于冷固结球团中,可有效吸附或包裹铁矿粉颗粒,增加黏结剂配比可同时提高球团的冷态抗压强度及高温抗压强度;在高温还原性气氛下焙烧冷固结球团,由于发生还原反应,球团金属化率提高,铁矿粉颗粒间空隙增大,导致球团强度下降,焙烧时间为30～90 min时,球团金属化率及抗压强度变化趋势最明显;焙烧初期,球团抗压强度不会发生快速下降,且焙烧结束后球团强度仍可保持为100 N/个左右。     

提高有机粘结剂球团强度的试验研究

Ｓ型粘结剂是一种粘性很大的有机物，具有极强的吸湿性，保水性和阳离子交换性，高温下全部燃烧挥发，但单独使用，焙烧温度在１２００－１２２０℃范围内，成品球团矿的强度很难满足大高炉冶炼的要求。为此进行了试验研究，研究结果：加入一定量的Ｘ型添加剂，可大大提高原有粘结剂球团的强度，满足生产要求。     

新型复合粘结剂提高生球质量的作用机理及构效关系

降低膨润土用量是提高球团品位、实现节能减排的有效途径之一。基于新型高效复合粘结剂,通过生球制备、线性拟合分析、生球力学特征分析等手段研究了复合粘结剂对生球质量的影响规律及与重要指标的构效关系,阐明了复合粘结剂提高生球质量的作用机理。结果表明:配比（质量分数）为1.2%膨润土+0.028%有机粘结剂的复合粘结剂球团,落下强度（0.5 m高度落下次数）达到6.2、平均抗压强度达到14.5 N、爆裂温度达到542 ℃,与2.0%膨润土球团相比,生球质量相近,但膨润土消耗减少40%;基于构效关系分析,有机粘结剂对生球落下强度、爆裂温度作用显著,膨润土对干球强度影响更大;有机粘结剂通过增强颗粒的亲水性、毛细力和黏性力强化了生球落下强度,干燥时在表层形成少量孔隙,有利于球团内水分的排出,提高了生球爆裂温度,干燥后以固态连接桥的形式强化干球强度,但是孔隙的位点和尺寸可能会降低干球强度,因此,对干球强度起决定性作用的是膨润土,有机粘结剂对干球强度的影响呈现多面性。      

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.     

Certain features of warm isothermal compression of iron powder

Processes of warm compression of mixtures of iron powder with organic binder (animal fat, zinc stearate) are investigated. Comparative experiments on the compressibility of SC-100.26 and PZhRV-200.28 iron with different binders are conducted. An increment in the density in warm compression of iron powder is achieved only where the iron powder is of high ductility, high purity, and the lubricants present in the mixture are of sufficient viscosity at the temperature and pressure of warm compression.     

铁矿球团用有机黏结剂研究进展

 随着钢铁行业绿色低碳转型,使用有机黏结剂替代膨润土已经是铁矿球团工序提质降耗的必然趋势。然而,有机黏结剂彻底替代膨润土的技术壁垒仍未突破,严重限制了其在工业生产中的广泛应用。有机黏结剂的黏结效用也是控制球团强度的关键因素,研究其在球团生产中的作用机理对提高球团强度以及开发具有国内知识产权的新型有机黏结剂意义重大。通过总结有机黏结剂在铁矿球团中的研究进展,旨在为其在中国钢铁行业的广泛应用以及新型有机黏结剂的研发工作提供理论指导与试验依据。在介绍理想有机黏结剂分子结构模型的基础上,揭示了4种常见有机黏结剂的结构及特性。重点讨论了黏度和吸水性对有机黏结剂黏结效用的作用机理,有机黏结剂的高黏度特性能够调节球团颗粒间液桥黏滞力大小,从而显著提高生球强度;吸水性是有机黏结剂调控生球自由水含量的重要特性,只有在最佳吸水率下,才能获得强度较高、粒径均匀的生球。总结了有机黏结剂的常见优缺点,其主要优点是微量高效、烧失量大、基本不影响球团铁品位,缺点是生产球团矿缺乏渣相固结而强度不足。分析了优化原料粒度组成、添加含硼化合物及分散剂等强化有机黏结剂球团生产的调控手段,并展望了有机黏结剂未来的发展方向。     

Preparation and characterization of sodium silicate/epoxy resin composite bonded Nd-Fe-B magnets with high performance

As an organic binder for bonded Nd-Fe-B magnets, epoxy resin(EP) has poor heat resistance but good moisture resistance, while sodium silicate(SS) has poor moisture absorption but better heat resistance and corrosion resistance. In order to improve high temperature stability and decrease moisture absorption of bonded Nd-Fe-B magnets, EP/SS composites were applied as the binder to prepare bonded Nd-Fe-B magnets. The magnetic properties, moisture absorption, corrosion resistance, compressive strength and microstructure of composite bonded magnets were investigated. The results show that EP/SS bonded magnets can obtain excellent magnetic properties at room temperature, and even useable magnetic properties a thigh temperature environments at 200°C. EP/SS composite binder effectively improves heat resistance and corrosion resistance of bonded Nd-Fe-B magnets, and reduces the hygroscopic properties. The molecule of sodium silicateis rigid and keeps it original shape at high temperature environments. In addition, SS in composite binder improves the mobility of the magnetic powders during the pre-pressing process, which makes the magnetic powders attain a more regular structure. These two factors will increase the mechanical properties. Moreover, sodium silicate in the composite binder can also cover the surfaces protecting the magnetic powders from oxidation and corrosion. EP in composite binder can cover SS surface to reduce the water absorption of SS as epoxy is a hydrophobic material. The EDX analysis shows that the composite binder has accumulated in the gaps of the magnet powders, which not only improves heat resistance and corrosion resistance, but also increases the mechanical properties. Therefore, EP/SS composite binder endows bonded Nd-Fe-B magnets excellent comprehensive properties.     

铁矿球团复合粘结剂技术经济评价

基于国内外球团矿复合粘结剂研究情况,介绍了球团矿粘结剂的理想模型及复合作用机理,详细论述了复合粘结剂种类、化学成分、基本物性,重点阐述了复合粘结剂对生球质量、成品球团质量、显微组织及其经济性的影响。目前,生产中广泛应用的是由膨润土和有机粘结剂制备的复合粘结剂,而添加镁质复合粘结剂、SF碱性粘结剂和含铁复合粘结剂是改善球团矿品质的重要途径,但其在生产中推广应用还有待进一步研究。