有机复合粘结剂特性表征及对球团矿性能的影响

摘要：添加有机粘结剂代替部分膨润土是减少成品球团矿的脉石含量的有效途径之一。通过残烧实验和XRD研究了膨润土与有机粘结剂间的相互作用,结果表明有机复合粘结剂比原始膨润土的晶层间距增加了008 nm。造球和焙烧实验结果表明,添加有机粘结剂替代膨润土可以提高生球落下和抗压强度。气基还原实验结果表明,添加有机粘结剂替代05%（质量分数）膨润土可以提高球团矿还原性,还原粘接指数也同时升高。SEM显微结果表明,添加有机复合粘结剂可以提高球团矿的孔隙率,有利于还原气体进入球团矿内部,从而改善球团矿的还原性。为制备有机复合粘结剂球团矿提供了参考,有助于扩大有机复合粘结剂在炼铁中的应用。     

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。     

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.     

铁矿球团添加一种新型有机粘结剂的试验研究

通过添加膨润土、新型有机粘结剂及两者一定的配比进行球团矿试验,研究对球团矿指标的影响,分析该型有机粘结剂作为球团粘结剂的可行性。试验结果表明:该新型有机粘结剂有利于提高球团矿的爆裂性能,但成球性较差,不宜单独使用;添加0.1%的该新型有机粘结剂,膨润土配比可从2.5%降到2%,球团矿的抗爆裂性能、成球性能得到提高。其成品球的铁品位升高了0.2个百分点,其抗压强度、高温冶金性能指标与不添加新型粘结剂的球团基本相当。     

鞍钢球团生产配加有机粘结剂的研究

通过实验室试验和工业试验,探索了有机粘结剂替代膨润土进行带式焙烧机球团生产的可行性。实验室研究表明:提高有机粘结剂的使用比例,生球落下和抗压强度、成球率、成品球抗压强度等指标都有不同程度改善,全铁品位明显提高;工业试验表明:单一使用0.8%有机粘结剂时,成品球团矿抗压强度提高,高温膨胀率显著降低,粉化指标有所变差,转鼓强度较为接近,全铁品位提高了0.2个百分点,试验前后球团矿的矿物组成都比较合理。只要能够满足经济成本的要求,鞍钢球团生产中配加有机粘结剂,在技术上完全可行。     

济钢球团配加碱性复合粘结剂试验

济钢在球团膨润土中配加碱性物料,采用雷蒙磨细磨,试验成功了低SiO2含量、造球粘结性能良好的碱性复合球用用粘结剂,取代以SiO2含量为主的膨润土类粘结剂。工业试验结果表明,配加该碱性复合粘结剂,提高了球团矿品位,改善了球团矿冶金性能,经济效益显著。     

新型有机粘结剂在球团生产中的应用

针对球团生产使用传统有机粘结剂存在的问题,开发了一种新型无土有机粘结剂及其造球专用立式混匀设备,并申请了专利.该技术在宣钢20万t/a回转窑球团生产线上应用后,结果表明:新型粘结剂完全可以取代膨润土,有效提高球团矿铁品位;同时预热球强度满足回转窑生产要求,球团矿冶金性能也能满足一般高炉要求.     

论提高球团矿品位与经济效益

本文分析了当前影响我国球团矿品位提高的因素。列举了用有机粘结剂取代膨润土来提高球团矿品位的试生产实例。通过计算论述了球团矿品位提高后带来的综合经济效益，以促进我国球团厂提高球团矿品位的工作进展。     

链篦机—回转窑工艺配加含铁有机粘结剂试验

介绍了宣钢炼铁厂链箅机—回转窑球团矿生产线配加含铁有机粘结剂代替膨润土生产球团矿的试验方案。基准试验方案为膨润土配比1.8%;部分代替方案为膨润土0.5%+粘结剂0.6%、膨润土0.8%+粘结剂0.6%;全部代替方案为粘结剂配加0.9%~1.2%。综合球团矿的各项技术指标,认为膨润土0.5%+粘结剂0.6%的配料方案效果最好。     

球团矿粘结剂的最佳选择

为了降低球团膨润土用量 ,进行了几种膨润土、有机粘结剂及有机 /无机复合粘结剂的造球试验 ,试验结果表明 :在本钢现有条件下 ,选择合适比例的钠基膨润土和有机粘结剂生产的球团矿能满足高炉冶炼要求 ,但复合粘结剂效果最好     

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。     

铁矿球团膨润土粘结剂提质改性研究进展

膨润土作为铁矿球团生产广泛使用的粘结剂,具有成球性能好、廉价易得的特点,但中国膨润土普遍质量差,直接使用时配加量常达到3％(质量分数)甚至更高,带来铁品位降低的问题.为降低膨润土用量,提高球团铁品位,国内外对膨润土的提质改性开展了广泛的研究,已达到能将膨润土用量降至1％甚至更低的技术水平.综述了膨润土分选提纯、钠化改性...     

Plate Water Absorption as an Assessment Tool for Organic Binders

Plate water absorption has been traditionally used to assess the binding ability of bentonite clay binders for iron ore concentrate pelletization. Until 1997, there was an accepted test by ASTM, but due to inconstant data this method was withdrawn. This value, however, is still used by some pelletization operations to gauge the efficacy of their bentonite. This test procedure has only been investigated on inorganic binders and never organic binders. This paper seeks to confidently prove that PWA can be used to accurately determine the efficacy of starch binders both alone and in conjunction with bentonite. The role of bentonite as a binder for iron ore concentrate is not only to hold agglomerates together during high temperature operations. But during pelletization it can also mitigate many times its own weight in water. This water absorption capacity aids in retarding the growth rate of pellets, as faster growing pellets tend to be weaker. The value of this water absorption, known as plate water absorption (PWA), is used as a metric to determine the strength and quality of the resulting pellets by industrial pelletizing facilities. As new low silica binders seek to replace bentonite, they too must take on the role of moisture mitigation. This study has shown that starches with lower water absorption capacities tend to have lower compressive strengths. As the water absorption capacity increases so too does the compressive strength. When using only starch, higher absorption capacities lead to lower compressive strengths of pellets exposed to elevated temperatures. When bentonite is used in conjunction with starch, higher water absorption mixtures do exhibit an increase in strength when heated.     

Study of Organic and Inorganic Binders on Strength of Iron Oxide Pellets

Bentonite is a predominant binder used in iron ore pelletization. However, the presence of a high content of silica and alumina in bentonite is considered undesirable for ironmaking operations. The objective of this study was to identify the alternatives of bentonite for iron ore pelletization. To achieve this goal, different types of organic and inorganic binders were utilized to produce iron oxide pellets. The quality of these iron oxide pellets was compared with pellets made using bentonite. All pellets were tested for physical strength at different stages of pelletization to determine their ability to survive during shipping and handling. The results show that organic binders such as lactose monohydrate, hemicellulose, and sodium lignosulfonate can provide sufficient strength to indurated pellets.     

钼精矿焙砂成型粘结剂的开发及作用机理

通过对多种具有粘结潜力的物质进行试验，选定了两种对钼焙砂成型具有明显效果的粘结剂ＬＢ和ＹＢ，并分别就其用量和成型水分对团块性能的影响进行了系统的研究。     

The Effect of Calcined Colemanite Addition on the Mechanical Strength of Magnetite Pellets Produced with Organic Binders

Iron ore pellets must have sufficient mechanical strengths against degradation in all stages of pellet production. Low strength is also a problem for product pellets since they abrade during transportation to the reduction furnaces. The use of a binder is necessary to provide sufficient strength to the pellets and for better operation and handling of pellets. Bentonite is the standard binder in the industry; however, it is considered an impurity due to its acid oxide contents. Organic binders have been tested for many years as alternative binder to bentonite. They have been found to give sufficient wet pellet properties. However, they failed to provide sufficient strength to the preheated and fired pellets due to lack of slag bonding. It has been assumed that one possible effective method to improve the preheated and fired pellet strengths is addition of a slag-bonding constituent. In this study, calcined colemanite was added to the pellet feed to overcome the lower strength problem encountered with organic binder use. The strength of pellets produced with organic binders and calcined colemanite alone and in combination was comparatively studied against the strength of pellets made with standard bentonite binder in magnetite concentrate pelletizing. The results showed that addition of calcined colemanite into the pellet mixture improved the preheated and fired pellet strengths of pellets produced with organic binders.     

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。     

Influence of tin on the structure and hardness of metallic binders of diamond tools fabricated by composition brazing

The influence of the tin content on the structure and hardness of Sn–Cu–Co and Sn–Cu–Co–W alloys, which are applied as binders of diamond abrasive tools, is investigated. The binders are prepared by compositional brazing: powdered components are mixed with an organic binder and deposited on a steel base. Sintering is performed at 820–1100°C. The structure of metallic binders is investigated by X-ray diffractometry and electron probe microanalysis. In addition, the microhardness of structural components and macrohardness of binders are measured. It is established that the hardness of metallic binders linearly increases with an increase in the tin content due to an increase in the amount of solid intermetallic phases in their structure. The optimal tin content, which provides high hardness (96–98 HRB) and the absence of lowmelting high-tin intermetallic compounds in their structure, is determined for Sn–Cu–Co–W binders.     

硬质合金新型粘结金属

介绍了硬质合金粘结金属研究领域中的新进展,论述了各种新型粘结金属的性能及用这些新型粘结金属制取的硬质合金的使用效果。表明这些新型粘结金属具有广阔的工程应用前景。