强化耐火材料管理 优化耐火材料使用

水泥企业耐火材料的管理是保证烧成系统正常运行的关键之一,耐火材料损坏事故的发生直接会导致烧成系统停产。因此强化耐火材料管理工作,不仅仅是降低耐火材料的耗量,还关系到烧成系统的优质高产低耗和长期稳定运行,所以水泥企业要把耐火材料的管理工作作为技术管理的一个重要方面,要不断强化耐火材料管理,优化耐火材料使用。1健全供应管理,把好进货质量合格的供应商是保证耐火材料质量的关键,南     

超高温隧道窑用耐火材料的标准和使用

本文叙述了用于耐火材料制品烧成的高温隧道窑的设计特点，特别注意到窑内能承受１７００℃以上的高温的部位。窑墙、窑顶以及窑车耐火材料的选择受这种特殊窑的设计的影响。本文集中叙述了烧成温度〉１８００℃时烧成优质耐火材料和碱性耐火材料使用的一些标准。熔融浇注耐火材料使用在隧道窑的关键部位是合理的。高级耐火材料的正确选择以及合理砌筑，改善了隧道窑的操作，延长设备寿命，并可提高制品质量。     

铝锆碳质耐火材料的性能研究

为提高铝锆碳耐火材料的性能,研究了烧成温度对铝锆碳耐火材料气孔率、体积密度、常温耐压强度的影响,得出了适宜的烧成温度范围和最佳的锆莫来石加入量,并对此进行了理论分析。同时,还研究了烧成温度对材料抗氧化性的影响。     

提高熟料产量的措施

<正>水泥熟料产量是在保证熟料质量和系统稳定的条件下所具备的生产能力。任何以牺牲系统设备和耐火材料为代价来提高烧成系统瞬时产量的做法,都可能造成设备和工艺事故,甚至引发安全事故。因此,为提高水泥熟料烧成系统的产量,应从优化设计、优化操作、选用优质原燃料等方面做工作。     

陶瓷辊棒的研究应用与发展

1前言 辊道窑由于具有烧成温差小、烧成周期短、成品率高、能耗低和易于控制等特点,在建筑卫生陶瓷(尤其是墙地砖和卫生洁具)、日用瓷、特种陶瓷和铁氧体的生产,以及玻璃和金属退火等行业得到广泛应用.随着辊道窑应用范围的日益扩大,对辊道窑的制造技术和所使用的耐火材料的要求在不断提高.在辊道窑中,辊棒是最关键的耐火材料,在窑炉中起着承载和传送产品的作用,即辊棒的强度和高温力学性能决定了辊道窑的使用温度与装载量,进而决定辊道窑的使用范围,因此研究和提高辊棒的性能是辊道窑得以进一步推广应用的关键所在.     

SiC质耐火材料的碳化氮化制备及性能

以Si粉和SiC颗粒为原料,采用碳化-氮化反应在1 400℃和1 500℃制备了SiC质耐火材料.采用X射线衍射仪、扫描电子显微镜和能谱仪等对试样的物相组成、显微结构和微区成分进行了分析,研究了原料组成和烧成温度对材料烧结性能、力学性能和抗热震性能的影响,并对原料组成和烧成温度进行了优化.结果表明:所制备的SiC质耐火...     

堇青石轻质熟料耐火材料

一、前言陶瓷快速烧成技术和旧窑炉的改造,迫切需要高热稳定性轻质耐火材料。我们在高热稳定性轻质耐火材料的研究工作中,改善堇青石合成料的高温性能,并用这种合成料做成轻质熟料,再制成容重为0.8—1克/厘米~3。的制品。使用温度可重达1300℃、热稳定性为1300℃—鼓风急冷热交换30次不炸、导热率为0.5～0.55大卡/米.时.度、耐压强度78.2公斤/厘米~2。这种耐火材料除适用于快速烧成窑车材料外,还适用于一般隧     

水泥回转窑系统耐火材料的设计与使用

耐火材料是保证水泥回转窑正常运行的重要材料,其产品性能、设计水平和砌筑技术等均会影响其使用寿命,并影响窑的运转率和熟料产质量。分析了窑系统运行时耐火材料所承受的应力,详细介绍了水泥回转窑常用耐火材料的品种与性能,在此基础上,对水泥回转窑烧成系统各部分耐火衬材料衬里的设计作了详细分析介绍。     

纳米Fe2O3对镁铬耐火材料烧结及力学性能的影响

在镁铬耐火材料中添加纳米Fe2O3,研究了它对镁铬耐火材料烧结性能与常温力学性能的影响.结果发现,在相同的工艺条件下,加入1%(外加)的纳米Fe2O3即可使镁铬砖的烧成温度降低150℃左右,并在相同烧成温度下能使试样的常温抗折强度和耐压强度大幅度提高.分析认为,在镁铬耐火材料中添加少量纳米级Fe2O3,可促进MgO-FeO固溶体中Cr3+和Al3+含量的提高,增强镁铬砖的直接结合程度,从而提高其力学性能.     

用Bayer法赤泥制备的多孔陶瓷滤料的结构与性能

实验以Bayer法赤泥为主要原料制备多孔陶瓷滤料,研究了赤泥添加量、烧成温度等对样品的烧成温度范围、显气孔率、压碎强度、耐酸耐碱性和显微结构等的影响.理化性能和显微结构测试表明:赤泥添加量和烧成温度是影响样品结构和性能的土要因素.赤泥添加质量达60%时,样品烧成温度为1 100℃,样品的显气孔率为31.78%,吸水率为15.34%,体积密度为2.07kg/m3,压碎强度为26.74MPa,耐酸性为93.54%,耐碱性为99.27%.样品的晶相组成为γ-Fe2O3、α-鳞石英、钠长石及斜辉石等,是一种气孔率高且强度高的优质滤料.     

Effect of mixing on the properties of nanocarbon containing Al2O3-C continuous casting refractories

The functional refractories used in steel casting operations are usually made up of alumina-carbon compositions having graphite as the major source of carbon. In recent times, to reduce the carbon content and to enhance the performance by designing microstructure at nano-sized level, several nano carbon sources and organic binders are introduced to traditional carbon-based refractories. The homogenous distribution of nano carbon sources within the refractory composition is important to get the advantages of its use. In the present work, nanocarbon black is used along with graphite in the alumina-carbon system. Three different mixing procedures are followed and how mixing effects the physical and mechanical properties is evaluated. The mixing order with proper nanocarbon distribution throughout the batch composition provided significant improvement in the properties. The microstructural analysis and in situ phase developments in the samples at different temperatures are also studied.     

含碳耐火材料用结合剂的现状及改进意见

介绍了含碳耐火材料用结合剂的生产现状、工艺过程、产品优缺点及其对成品砖质量的影响情况,并提出了提高各类结合剂质量的改进措施。     

Nanotechnology in castable refractory

In recent times nanotechnology has drawn significant attention in the field of refractory research. Different nano-powders and colloidal suspensions have been utilized to improve the properties of refractory castables. Various studies have been carried out worldwide with nano scaled binders; such as, hydratable alumina (HA), colloidal alumina (CA), colloidal silica (CS), micro silica, etc.; to improve the thermo mechanical properties of refractory materials. Nano scaled additives are also being applied to reduce the energy consumption and to improve the densification process at lower temperatures. In this paper, the contributions of nanotechnology in selection of raw materials, the binders and choice of additives to improve the quality of refractory materials, and the future of nanotechnology in refractory research are reviewed.     

Raw materials,microstructure, and properties of MgO–C refractories: Directions for refractory recipe development

A range of steel making vessels and continuous casting components use graphite containing MgO-C refractories that work from ambient to 1600 °C or higher. In the current study, a detailed review on the key importance behind the rightful selection of raw material quality in the development of MgO-C refractories with improved high-temperature microstructure stability is provided. Special cases of carbon\ceramic reinforcements (SiC, nanocarbon, EG, CNT’s, Zircon, Titania) are also included in this review study with the combination of regular raw materials used in refractory formulation such as magnesia, graphite, resin binder, antioxidant additives, and alloys thereof. Additionally, the material design concept based on strength factor (f_s) has been applied to implicate the raw material quality analysis in the development of carbon containing refractory recipe exhibiting satisfactory hot-strength performance with the recyclable MgO-C grog over the commercially available carbon\ceramic reinforcements is discussed.     

Nanocarbon containing low carbon Al2O3–C refractories: Comparison between N220 and N990 nanocarbons

Continuous casting process is the majorly used solidification process in steel fabrication. The refractories used in this process are most commonly made up of alumina-carbon-based compositions. Generally, these functional refractories consist of about 30% residual carbon after coking. Improvements in steel industries, such as attaining clean steel and ultralow-carbon steel, require alumina-carbon refractories with low carbon content. In the present work, low carbon-containing Al₂O₃–C refractories are studied by using two different grade nanocarbons, namely, N220 and N990 with varying amounts, along with fixed 3-wt% graphite in the batch composition. The physical, mechanical, and thermomechanical properties along with the oxidation resistance are evaluated and compared. Phase analysis and microstructural developments at different temperatures were also characterized. Optimized compositions of both the nanocarbons are further studied for hot strength and oxidation resistance measurement. Based on all the obtained results, one batch composition is finalized for the thermal shock and corrosion testing. All the results are compared against a reference batch composition containing 25% graphite as a carbon source. The formation of in situ ceramic phases like aluminum carbide in nanocarbon-containing compositions provides a dense compact microstructure that improves strength, helps to inhibit oxidation, and contributes to corrosion resistance.     

耐火材料与洁净钢的关系

从化学热力学分析讨论了耐火氧化物及复合氧化物与钢液中平衡氧含量的关系 ,钢液中氧含量与氧势的关系 ,耐火氧化物与钢中硫含量 ,耐火氧化物及结合剂与钢中磷含量 ,耐火材料中残余水分及有机结合剂与钢中氢含量的关系 ,以及炼超低碳钢时的碳污染等问题。     

MgAlON对碳结合制品性能的影响

采用合成MgAlON部分或全部取代铝碳砖和铝镁碳砖中的基质部分 ,并测试其对材料密度、强度、抗氧化性和抗渣性能的影响。结果表明 :在铝碳和铝镁碳耐火制品中加入MgAlON后 ,体积密度上升 ,耐压强度提高 ,抗氧化性能改善 ,抗渣性能略有降低但仍保持较好水平     

Unfired periclase-carbon refractories with a thermoreactive polymer binder

Elevated environmental requirements necessitate the development of new binders with a high carbon residue, heat treatment of which does not result in emission of toxic or carcinogenic substances. Such binders should have adequate technological properties. It is shown that it is possible to use a thermoreactive polymer binder based on a resorcinol oligomer for production of periclase-carbon refractories. The binder is soluble in water and organic solvents and possesses a high carbon residue (> 60%). Specimens of periclase-carbon refractories with the suggested binder and 5–12% graphite exhibit good ceramic and mechanical properties. Translated from Ogneupory i Tekhnicheskaya Keramika, Nos. 1–2, pp. 19–24, January–February, 1999.     

New refractory concretes and binding systems: Basic trends of development, production, and use of refractories in the XXIst century. Part I. Trends of development, binding systems

General trends in the development, production, and service of refractories are considered. The share of refractories used in ferrous metallurgy amounts to 60–70%, which means that the predominant trend is determined by the requirements imposed on the refractories used in the steel industry. The proportion of unshaped refractories in the total production will inevitably grow. The basic problem in this field is the improvement of their matrix (disperse) phase, i.e., the binding system. The main types of refractory binders, of which highly concentrated ceramic binding suspensions (HCBS) are the most interesting, are considered. In contrast to natural ceramic binders (clays) HCBS are artificial systems that can be obtained on the basis of many refractory materials. The priority aspect in the creation of new refractory concretes (castables) and binders is described. The first artificial ceramic binders and cement-free refractory concretes based on them were created and installed by the author at the end of the 60s, and in the 70s he suggested many types of ceramic castables, including superlow-cement ones. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 2, pp. 4–13, February, 1998.     

Novel drying additives and their evaluation for self-flowing refractory castables

The drying step of dense refractory castables containing hydraulic binders is a critical process, which usually requires using slow heating rates due to the high explosion trend of such materials during their first thermal treatment. Thus, this work investigated the performance of alternative additives to induce faster and safer drying of self-flowing high-alumina refractory castables bonded with calcium aluminate cement (CAC) or hydratable alumina (HA). The following materials were analyzed for this purpose: polymeric fibers, a permeability enhancing compound (RefPac MIPORE 20) and an organic additive (aluminum salt of 2-hydroxypropanoic acid). The drying behavior and explosion resistance of the cured samples were evaluated when subjecting the prepared castables to heating rates of 2, 5 or 20 °C/min and the obtained data were then correlated to the potential of the drying agents to improve the permeability and mechanical strength level of the refractories at different temperatures. The collected results attested that the selected additives were more efficient in optimizing the drying behavior of the CAC-bonded compositions, whereas the HA-containing castables performed better when the aluminum-based salt was blended with a small amount of CAC (0.5 wt%), which changed the binders hydration reaction sequence and optimized the permeability level of the resulting microstructure. Consequently, some of the designed compositions evaluated in this work showed improved drying behavior and no explosion was observed even during the tests carried out under a high heating rate (20 °C/min).