不定形耐火材料中减水剂的研究及应用

针对不定形耐火材料中减水剂的重要作用,概述了减水剂的分类,减水剂与不定形耐火材料的作用机理,减水剂在不定形耐火材料中的研究及应用现状,并对其在浇注料中的发展前景进行了展望。     

使用不定形耐火材料应注意的问题

使用不定形耐火材料应注意的问题１材料选择衡阳钢管厂在环形加热炉、步进炉上均采用不定形耐火材料。其材料有粘土浇注料、高铝浇注料、高强度粘土浇注料、钢纤维增强浇注料、低水泥浇注料等。各种材料的性能和使用条件都不尽相同，要针对炉体各部位的实际情况选用合适的...     

分散剂在不定形耐火材料中的应用

概述了分散剂的发展历史,介绍了不定形耐火材料分散剂的作用机制和基质颗粒的作用能,探讨了不同分散剂对不定形耐火材料流变性的影响,并展望了不定形耐火材料分散剂的发展方向。     

水泥回转窑烧嘴用浇注料使用寿命的提高

在水泥回转窑中采用多种不定形耐火材料,大多数情况下采用高铝质不定形耐火材料.文中介绍了向高铝砖耐火浇注料中加入SiC料在回转窑烧嘴中试用情况.     

硅溶胶结合不定形耐火材料的研究及应用现状

总结了硅溶胶结合不定形耐火材料(包括浇注料、捣打料、喷射料和压入料)的性能研究和应用现状,并展望了硅溶胶结合耐火材料技术研究的方向和前景。     

低水泥/无水泥浇注料在钢包冶金中的应用前景

不定形耐火材料越来越多地替代耐火砖应用于钢包冶金中,尤其是低水泥/无水泥浇注料。介绍了不定形耐火材料在冶金行业中的演变过程,以及今后的发展方向。     

日本浇注料技术的最新进展

过去20年里,日本耐火材料的产量大幅下降。但由于在钢铁行业工业窑炉内衬上的应用,不定形耐火材料产量只有小幅下滑。不定形耐火材料的改进和用不定形材料进行中期修补技术的有效使用,延长了炉役,导致耐火砖的用量下降。介绍了不定形耐火材料的概况,并以日本目前浇注料技术的发展现状和未来面临的挑战为主题进行阐述。     

耐火可塑料

一、概论耐火材料按形状可分为定形的和不定形的。定形的为各种烧制砖;不定形的主要包括浇注料(即耐火混凝土),捣打料,可塑料和喷涂料,它们都是不烧的耐火材料。在耐火材料的发展上,烧制砖、不定形耐火材料和耐火纤维分别属于第一、二、三代产     

不定形耐火材料与定型耐火材料的对比

不定形耐火材料在世界耐火材料产品总量中所占的份额持续上升。这种趋势主要与新产品的性能改进和引入新的施工技术有关。本文简要叙述了先进耐火浇注料的研发,并且将不定形耐火材料的性能与类似的定型制品的性能进行了比较。讨论了在不同的高温工业应用中不定形耐火材料替代定型制品的使用。     

不定形耐火材料发展的新动态

介绍和评述了不定形耐火材料在结合系统、材质和新品种、施工方法、不定形耐火材料的定形化等方面的发展新动态。结合系统向着尽可能减少由结合物带入杂质成分的“纯净化”的方向发展和向着在受热过程中减少结合物的挥发和分解以减少对材料结构破坏的“稳定化”的方向发展。为满足更高的使用温度、抗渣性、洁净钢的冶炼和有温度急变的高温部位使用 ,导致了MgO基浇注料、含天然鳞片石墨的浇注料以及含阿隆 (AlON)、塞隆 (SiAlON)的浇注料等新材质和品种的出现以及这些方面研发工作的活跃。施工方法向着简便化、机械化和高效化的方向发展。从烘烤的角度看 ,更多的不定形耐火材料具有可以快速乃至免烘烤的特性。与施工方法和高效烘烤相适应 ,出现了自流浇注料、湿式喷射料、自流渗浆浇注料、干式振动 /捣打料、免烘烤捣打料和预制件应用增加的趋势。随着预制件的采用日益增多 ,“定形”和“不定形”的界限正在变得模糊。     

Abstracts from Naihuo Cailiao （ Refractories ） ——A Chinese-Language Bimonthly

Preparation and oxidation resistance of U4 C--partly graphitized carbon black compound powders;Slag resistance of MgO-Cr203 refractories in vacuum condition;Effect of TiN and Ai on properties of MgO-C brick;Effects of sintering aids CeO2 and MgO on sintering properties of bauxite based homogenized mullite grogs;Rheological property of self-flowing slurry-permeating corundum castables;     

超细粉在不定形耐火材料中的应用

超细粉在不定形耐火材料中的应用张战营，孙承绪，李再耕（华东理工大学无机材料系上海２００２３７）（洛阳耐火材料研究院洛阳４７１０３９）ＴｈｅＡｐｐｌｉｃａｔｉｏｎｏｆｔｈｅＵｌｔｒａＦｉｎｅＰｏｗｄｅｒｓｉｎｔｈｅＭｏｎｏｌｉｔｈｉｃＲｅｆｒａｃｔｏｒ...     

粘稠物系三相流态化结晶过程的流变学特性

采用DV—Ⅰ型旋转式粘度计测定了高粘度蔗糖三相系统的流变学特性,以探讨蔗糖三相流态化结晶过程的流交流动行为。结果表明,三相高粘系统的流体仍为牛顿流体;体系的表观粘度随固含率的增加而增加,随气含率的增加而下降。进而分析了蔗糖三相流态化冷却结晶的可行性。     

减水剂对超低水泥Al_2O_3－Cr_2O_3ZrO_2质浇注料流变性能的影响

对添加三种有机高分子减水剂和两种聚磷酸盐碱水剂的Ａｌ２Ｏ３－Ｃｒ２Ｏ３－ＺｒＯ２质浇注料桨体与泥料流变参数进行对比。研究表明，在加有Ａｌ２Ｏ３、ＣｒＯ３超细粉，以纯铝酸钙水泥为结合剂的浇注料中，有机减水剂的作用效果更为显著。对减水剂的作用机理和作用规律以及ξ电位，流变参数和流动值的关系作了探讨。     

Build-up formation and corrosion of monolithic refractories in cement kiln preheaters

Nowadays, the cost of energy and the environmental standards have encouraged cement manufacturers to replace conventional fuels by alternative fuels (industrial wastes and agricultural and forest residues). Therefore, the increasing uses of these alternative fuels in cement plants have severely increased build-up formation and attack of the monolithic refractories used. All this strongly affects the durability of the refractory castables. In order to investigate this issue a number of samples, taken from five cement kiln preheaters, were studied. The results obtained confirm that the build-up constitution varies broadly and they consist of alternate layers of slightly different compositions as a consequence of changes in operating conditions of the furnaces. Their growth and compactness are due to a vitreous phase formation. On the other hand, the main compounds causing the attack of the monolithic refractories are: K₂O, SO₃, CaO and Cl^?. These give place, in the matrix of the refractory material, to a liquid phase together with minor amounts of different crystalline phases. The depth of the attack depends on the SiC content in the refractory castable, as the proportion of SiC in the matrix increases the depth of attack decreases. The liquid phase brings about the adherence of the ring to the refractory castables. Therefore, when build-up is removed, part of the refractory material adhered to them is also removed. The thickness of the peeled off material depends on the depth of the attack.     

Low-cement castables of corundum and aluminum compositions

The effect of the mineral and grain composition of charges and the manufacturing technology and characteristics of vibroshaping of low-cement thixotropic castables having an alumosilicate and a corundum composition on the physicochemical properties of the obtained material are considered. Experimental refractories fabricated of low-cement castables have been tested in intermediate ladles of a continuous casting machine. The developed low-cement thixotropic castables possess high physicomechanical and operational properties and can be used in various metallurgical equipment.     

Evaluation of the requirements for the rheological characteristics of the polymer solution for production of high-strength polyaramid fibres

Rheological studies of samples of spinning solutions on a Rheotest 2 viscometer showed that for the same viscosity values determined with the falling ball method, the rheological characteristics such as the flow index, initial Newtonian viscosity, and apparent viscosity, differ. The highest strength of aramid fibres is attained in spinning from a spinning solution with the following rheological characteristics: apparent viscosity of 59.3 Pa⋅sec, initial Newtonian viscosity of 73.2 Pa⋅sec, and flow index of 0.808.     

钢包粘渣与包衬耐火材料

阐明了钢包粘渣与包衬耐火材料存在一定的关系 ,抗渣渗透性差、容易出现开裂的包衬耐火材料容易粘渣。为防止钢包粘渣 ,适于采用抗侵蚀性和抗渣渗透性优良的尖晶石砖、铝尖晶石 (或铝镁 )浇注料、低密度浇注料以及抗剥落性好的刚玉 -锆英石浇注料作包衬耐火材料     

Temperature and common-ion effect on magnesium oxide (MgO) hydration

MgO based refractory castables draw wide technological interest because they have the versatility and installation advantages of monolithic refractories with intrinsic MgO properties, such as high refractoriness and resistance to basic slag corrosion. Nevertheless, MgO easily reacts with water to produce Mg(OH)₂, which is followed by a large volumetric expansion, limiting its application in refractory castables. In order to develop solutions to minimize this effect, a better understanding of the main variables involved in this reaction is required. In this work, the influence of temperature, as well as the impact of the chemical equilibrium shifting (known as the common-ion effect), on MgO hydration was evaluated. Ionic conductivity measurements at different temperatures showed that the MgO hydration reaction is accelerated with increasing temperature. Additionally, different compounds were added to evaluate their influence on the reaction rate. Among them, CaCl₂ delayed the reaction, whereas KOH showed an opposite behavior. MgCl₂ and MgSO₄ presented similar results and two other distinct effects, reaction delay and acceleration, which depended on their concentration in the suspensions. The results were evaluated by considering the kinetics and the thermodynamics of the reaction, and the mechanical damages in the samples that was caused by the hydration reaction.