硅砖成型用摩擦压砖机及烧成用天然气烧嘴的改造

为了节能降耗,降本控费,对硅砖成型生产中能源利用率低和存在跑风、漏风现象的摩擦压砖机的传动系统、阀门和输气管道进行了一系列的改造;同时对硅砖烧成隧道窑天然气烧嘴的喷枪及旋流片也进行了一系列改造,从而降低了硅砖生产成本及烧成费用。     

硅砖的回顾与展望

回顾了硅砖的发展进程，总结了硅砖生产的经验，指出了硅砖生产中现存的问题，并提出了整改措施及科研方向。     

磷酸—硅质捣打料在玻璃熔窑上的应用

不定型耐火材料成本低廉,使用方便,应用日益广泛。以磷胶结的硅质混凝土具有组织致密,在低、中、高温下耐压强度较高的优点。这种硅质混凝上不仅保持了硅砖的基本特征,而且其耐火度和荷重软化点比普通硅砖还高40一60CC。为了探索磷酸一硅质混凝土代替硅砖在玻璃窑上的使用效果,     

印度焦炉硅砖的蠕变特性

蠕变性能是检定耐火材料负荷能力的非常重要的指标。对于焦炉硅砖来说也是一样,其蠕变应尽可能低。试样在1450℃的恒定温度下,承受5kg/cm~2的压力,加热25小时后,其蠕变应不超过0.35％。耐火材料厂为了达到这样的低蠕变值,使用了不同的方法。在印度,已经能够生产蠕变低达0.05％的硅砖,这个数值比其他国家生产的硅砖低得多。发现鳊硅砖的残余石英小于1％时,也不会出现高的蠕变值。当残余石英小于0.2％时,蠕变只有0.12％。     

高致密硅质耐火材料的生产与性能研究

开滦精煤股份有限公司一期建有两座JN60—6型焦炉,其炭化室炉头普通硅砖因周期性温度波动导致硅砖产生裂纹、结构疏松、表面剥落。针对焦炉硅砖损坏情况及焦炉大型化的发展要求,开发高致密硅砖成为亟待解决的问题。     

用复合矿化剂试制优质硅砖

用复合矿化剂试制优质硅砖唐山马家沟耐火材料厂李树林采用石灰乳一铁质（ＣａＯ－ＦｅＯ）作矿化剂生产的硅砖，由于其真密度高、鳞石英含量低，特别是引入砖中的ＦｅＯ是硅砖使用时炭素沉积的催化剂，有促使硅砖砌体结构松散，降低使用寿命的缺陷。现代焦炉向大型化方向...     

晶相组成对硅质耐火材料抗碱侵蚀性能的影响

硅砖属于酸性耐火材料，具有高荷重软化温度和抗酸性渣侵蚀能力，但抗碱侵蚀能力很差，因此研究不同硅砖的抗碱侵蚀能力对硅质耐火材料的应用有重要意义。本文选用了四种硅砖(JG-95^#硅砖、BG-96A^#硅砖、ZES-99^#硅砖和DES-99^#硅砖),采用化学分析、显微结构分析、X射线粉末衍射分析和显气孔体密度分析等方法对比分析了四种不同硅砖晶相组成和晶相转变对抗碱侵蚀能力的影响，结果表明，ZES-99^#硅砖和DES-99^#硅砖的抗碱侵蚀能力明显优于JG-95^#硅砖和BG-96A^#硅砖，即二氧化硅含量较高的硅砖抗碱侵蚀能力更强，并且以方石英、鳞石英和熔融石英为主晶相的硅质耐火材料都具有良好的抗碱侵蚀能力。     

硅砖熔洞的成因

通过硅砖熔洞、铁斑在硅砖检验中的重要性的阐述,对生产过程中出现的一些硅砖熔洞进行原因排查,探讨了硅砖铁洞、钙洞的成因及应采取的预防措施。     

硅砖的研究进展及应用

综述了硅砖的研究进展及应用;其中,主要总结了硅砖所用原料的种类、矿化剂的选择以及添加物对硅砖性能的影响,并介绍了硅砖的应用及潜在的发展方向。     

热风炉高温区用硅砖中鳞石英的结构演变

研究了热风炉蓄热室中部(工作温度1 470℃)使用10a以上硅质格子砖的性状,对使用前后硅砖的相组成、微观结构和物理性能进行了表征和分析,检测了使用前和使用后的硅砖蠕变性能,结果表明:1 450℃使用前后硅砖的蠕变率分别为0.008%、-0.025%;1 550℃使用前后硅砖的蠕变率分别为-0.154%、-0.135%。用后硅砖只有鳞石英相存在,1 450℃用后硅砖蠕变相当于纯鳞石英陶瓷的蠕变特征。用后硅砖中鳞石英呈连续网络状分布,表现为优良的抗蠕变性能。1 550℃用后硅砖蠕变的特征为有部分鳞石英向方石英转变过程。硅砖微观结构从使用前的典型骨料-基质耐火材料结构演变为使用后的均质化鳞石英陶瓷材料结构。建立了硅砖微观结构演变的反应机理模型。     

Properties of New Mullite-SiC Bricks for CDQ Shafts

Currently the service life of CDQ shafts in China is mainly restricted by the properties of the inclined flue bricks.In this work,based on the systematic analysis of the damage mechanism of inclined flue refractories,high performance mullite-SiC bricks were developed.The bricks were produced by corundum,andalusite,SiC and other high purity raw materials.Metal silicon and alumina ultra micropowder were added to form dispersion multi-phase structure,fortifying the matrix and improving the microstructure.The products have excellent properties such as low porosity,high density,good wear resistance,high refractoriness under load,and good thermal shock resistance.The products can replace the ordinary mullite-SiC bricks and obtain a good service life.     

Adherence Characteristics of Cement Clinker on Basic Bricks

Based on the sandwich test,adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodoluminescence technique.Doloma based bricks offer sufficient lime to react with clinker,forming C3S rich layer and initializing superior adherence.However,clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks,which reduces adherence strength.On magnesia spinel bricks,fine crystalline spinel easily reacts with lime containing phases from clinker to form lowmelting phases and belite zone,which shows high adherence performance.Lack of fine spinel in magnesia spinel bricks results in poor adherence.     

优质硅砖生产中原料除铁工艺及添加剂自动添加系统的研发

为提高硅砖的成品率和性能指标,进一步降低产品能耗,研究了硅砖生产过程中容易影响制品性能和成品率的关键环节和设备,并参考国内外先进技术,研发出原料除铁工艺及添加剂、矿化剂自动添加系统,确定了优质硅砖生产线相应环节的最佳技术方案,最大限度地提高了成品质量并降低能耗。     

Reactions of Secondary Phases with Carbon in Magnesia‐Carbon Bricks

Despite the excellent thermochemical properties of magnesia carbon bricks, these exhibit one weak characteristic during their use: their carbothermally induced wear. Carbon has a high affinity to oxygen, which leads to a reaction between magnesia and carbon, forming gaseous products at very low oxygen partial pressures in the surrounding atmosphere. When magnesia carbon material is furthermore applied at negative pressures, the precited carbothermic reduction processes effect an internal decomposition or even degradation of the bricks. Mostly, high‐purity magnesia varieties (MgO ≥ 96 wt%) are used for the production of magnesia carbon bricks because the low‐melting calcium silicate secondary phases in magnesia impair the high‐temperature resistance of these bricks. The fundamental question if and to which extent secondary phases react with carbon and which impact they have on the carbothermally induced wear of bricks has been unsolved so far. The following paper presents which influence the mineral secondary phases, monticellite, merwinite, and belite that are most commonly occurring in magnesia, have on the carbothermally induced wear. The respective studies were conducted by means of thermogravimetric and microstructural analyses. The results of these studies show that monticellite in the MgO–C microstructure brings about an increase in weight loss on account of carbothermic reduction processes. On the contrary, belite and merwinite in the MgO–C structure do not exhibit any negative impact on the thermal stability of the microstructure.     

Investigation on Production and Markets of Silica Bricks in China

The annual output of China‘s silica brick amounts up to over 300 thousand tons, which accounts for more than 70% of the total oupout of silica bricks in the world. Besides satisfying domestic markets, China‘s silica bricks have been exported to many countries and retions such as Japan, USA etc. In this paper, the situation of silica bricks production, technology, sales and exporting have been described. Also suggestions on improvement of silica bricks quality and exporting, corporation with foreign partners have been put forward in order to win larger market share both aat home and abroad.     

m-ZrO2和ZrSiO4对MgO-CaO砖性能的影响

以镁钙砂、中档镁砂、高纯镁砂粉、单斜氧化锆(m-ZrO2)、锆英石等为原料,研究了ZrO2的加入形式与加入量对MgO-CaO砖性能的影响。结果表明:当ZrO2以m-ZrO2的形式加入到MgO-CaO砖中时,可以提高试样的常温性能、抗水化性、抗热震性等,m-ZrO2加入量(质量分数,下同)为2%~7%时,试样具有良好的常温性能,加入量为5%时抗水化效果较好,加入量为10%~15%时抗热震效果较好;当ZrO2以锆英石细粉的形式加入时,会明显提高试样的抗水化性及抗热震性,锆英石加入量为5%时,试样的抗水化性及抗热震性优越,但随着锆英石加入量的增加,试样的体积密度、强度明显下降,加入量大于10%以后,制品大多疏松开裂。     

硅石—碳化硅窑具砖

针对硅砖使用过程中易断裂的弊病,在其生产工艺的基础上,以碳化硅代替部分硅石克服之。碳化硅的加入量为15％。初见成效,30％效果明显,1100℃的水冷次数高达13次。硅石—碳化硅砖集硅砖和碳化硅砖之优点而兼具荷重变形温度高,热震稳定好的特点。作为耐火材料烧成用的高温窑具,使用寿命比硅砖提高五倍以上。     

Comparative assessment of Australian fly ash and conventional concrete bricks

A comparative study of the chemical composition, mineralogy, morphology and crushing strengths of fly ash bricks, conventional concrete bricks and fly ash samples has been undertaken. The main chemicals present in the products were silica and alumina while their main minerals were quartz, mullite, illite, vaterite, and calcite. Elemental analysis by XPS showed that the major elements in the samples were oxygen, silicon, carbon, calcium and aluminium; and scanning electron microscopy revealed that the fly ash samples consist of spherically‐shaped particles with surface attachment containing needle‐like particles. Compared with conventional concrete bricks, fly ash bricks generally have higher atomic silicon and crushing strengths but lower crystalline silica. The implication of the results on the suitability of fly ash bricks as replacements for conventional concrete bricks in the building industry is discussed from the point of view of human health and occupational safety. Copyright © 2004 Society of Chemical Industry