合理选择和使用耐火砖消除铬对环境的危害

水泥窑用镁铬砖的残砖中铬含量较高，对环境危害大。为降低铬盐对环境的危害，牡丹江新材料科技股份有限公司在水泥窑上进行了使用低铬砖和无铬砖的试验。试验表明，加锆改性尖晶石砖的使用情况较直接结合镁铬砖差，而加铬方镁石复合尖晶石砖(LYC砖)的使用效果好于直接结合镁铬砖。LYC砖不仅铬含量低，对环境的危害小，且其使用寿命是普通镁铬砖的5倍，是直接结合镁铬砖的1．72倍。使用LYC砖对提高窑运转率，降低生产成本有利。     

特种直接结合镁铬砖和高档尖晶石砖的研发和应用

<正>直接结合镁铬砖和尖晶石砖作为水泥回转窑烧成带、过渡带窑衬材料已有悠久历史。现在国内外直接结合镁铬砖和尖晶石砖已发展成系列化,有多种产品可供     

白云石砖在水泥窑的使用

0 前言 目前,在水泥窑烧成带使用的碱性砖主要是镁铬砖、镁尖晶石砖和白云石砖。由于镁铬砖存在公害问题,故有被镁尖晶石砖和白云石砖所取代的趋势,水泥窑用碱性砖将实现无铬化。这里仅就白云石砖在水泥窑的使用问题略述如下,供参考。     

水泥窑用低铬优质镁铬砖的研制

本文介绍了结合我国国情采用增铝、增铁的技术路线研制的低铬优质镁铬砖以代替普通镁铬砖，当Ｃｒ２Ｏ３＜４％时仍具有优良的热震稳定性和粘挂窑皮性。该砖已经在牡丹江水泥厂１＃窑烧成带使用了两个窑次，具良好有使用性能     

白云石砖在窑外分解窑上的试用

白云石砖在窑外分解窑上的试用梁忠博辽宁省本溪水泥厂（１１７０１９）我厂３号窑为１２００ｔ／ｄΦ３．７ｍ×５３ｍ的窑外分解窑，窑内烧成带衬料长期使用普通烧结镁铬砖。由于镁铬砖在水泥窑内使用中砖内Ｃｒ２Ｏ３组分与窑气、窑料中的碱、硫等相结合，形成有毒的Ｃ...     

几种新型耐火材料在蓄热室中的试用情况

为了延长蓄热室格子砖的使用寿命,避免由于热修频繁给生产带来的影响,我厂在本窑期同北京建材研究院、西安冶金建筑学院、蚌埠玻璃工业设计院、洛阳耐火材料厂、冷水江耐火材料厂等六单位共同组成了协作组,拟定在我厂二号窑蓄热室中,进行国产六种新型耐火材料的综合性试验.这六种耐火材料主要包括:北京建材研究院研制的熔铸十字形锆刚玉砖;洛阳耐火材料厂生产的电熔再结合镁铬砖;全合成镁铬砖、预反应镁铬砖、普通镁铬     

新型干法水泥窑高温带用无铬砖的研制及应用

<正>镁铬砖在水泥窑高温带使用后会产生致癌物质六价铬盐化合物,西方发达国家已限制或禁止镁铬砖在水泥窑上使用,国内由于没有合适的无铬砖替代镁铬砖,所以镁铬砖仍在国内水泥窑高温带大量使用     

水泥旋窑常用耐火材料的品种及消耗

水泥旋窑可分为传统窑和新型干法窑。传统窑包括湿法窑、干法窑和立波尔窑。这类窑虽然生产工艺不尽相同,但对耐火材料的要求基本一致。新型干法窑是指预热器(SP)窑和预分解(PC)窑。这类窑,尤其是日产2000吨以上的大型窑,对耐火材料的要求很高。目前我国传统的耐火材料多数由冶金系统和地方的耐火材料厂供应,而大型新型干法窑的耐火材料,则主要依赖进口。 1 水泥旋窑常用的耐火材料 水泥旋窑主要用铝质和镁质两类耐火材料。镁质材料也称碱性材料。常用的铝质材料有粘土砖、高铝砖和磷酸盐结合铝质砖;镁质材料有普通镁铬砖、直接结合镁铬砖和尖晶石砖。此外,常用的还有耐碱粘土砖。现     

方镁石复合尖晶石砖在短窑上的应用

我公司回转窑规格为φ3.962m×42.672m2000t/d预分解窑,1995年投产以来,烧成带大部分时间使用直接结合镁铬砖,投产初期和2002年出现红窑事故时烧成带也曾用过普通磷酸盐砖,其寿命周期只有20d左右。而烧成带使用直接结合镁铬砖,其寿命周期从开始的60d左右经过8年的时间到2002年上半年,也只有128d。由于窑型短,烧成带火力相对集中,使用直接结合镁铬砖,2002年前窑衬耐火砖一直不能提高使用寿命,常常一年多次更换耐火砖,严重制约了生产。自2002年7月使用方镁石复合尖晶石砖后大大提高了回转窑耐火砖的使用寿命,为我     

水泥窑用低儿优质镁铬砖的研制

本文介绍了结合我国国情彩 增铝，增铁的技术路线研制的低铬优质镁铬砖色代替普通镁铬砖，当Ｃｒ２ｏＣ〈４％时仍具有优良的热震稳定性和粘挂窑皮性。该砖已经在徨丹江水泌厂１＾＃窑烧成带使用了两个窑交俱有良好有使用性能。     

Slag Resistance of Refractories for Direct Reduction of Laterite Nickel Ores in Rotary Kilns

Aiming at prolonging the service life of refractories for direct reduction of laterite nickel ores in rotary kilns, the slag resistance of ten materials(corundum bricks, chrome corundum bricks, silicon nitride bonded silicon carbide bricks, high alumina silicon carbide bricks, high alumina bricks, magnesia chrome bricks, magnesium aluminate spinel bricks, spinel chrome corundum bricks, chrome corundum castables and magnesia alumina chrome composite spinel bricks) was evaluated by rotary slag tests, which simulate the service conditions in rotary kilns. The corroded residual bricks were analyzed by SEM and EDS. The results show that the magnesia alumina chrome composite spinel brick possesses the advantages of magnesium aluminate spinel bricks and chrome corundum bricks; MgO-rich spinel can absorb the penetrated ferric oxide, and forms a dense zeylanite layer, which prevents the penetration of the molten laterite nickel ores; therefore, it is an ideal lining of rotary kilns for direct reduction of laterite nickel ores.     

我国陶瓷工业用耐火材料现状与发展

介绍了隧道窑、梭式窑和辊道窑用耐火材料的选用,重点概括了堇青石-莫来石制品、碳化硅制品、陶瓷纤维、氧化铝辊棒和轻质耐火砖5类陶瓷工业用耐火材料,并提出了我国陶瓷工业用耐火材料发展应注意的问题。     

A Short Communication on Refractories as Kiln Lining along Various Thermal Zones in Pre-calcining Cement Rotary Kiln

Modern cement rotary kiln is often large in size while rotating in high speed. Thermal condition within a rotary kiln is rather complex,exerting severe thermal and chemical attack on refractory of its kiln lining. In the present paper,the cause that leads to refractory failure was analyzed; requirements for refractory to overcome such failure was discussed. Composites and properties of different refractories most often used as kiln lining were assessed,including magnesia-chrome bricks,magnesia spinel bricks, dolomite bricks, silicon carbide mullite bricks and castables etc. Recommendation was made for refractories with suitable composites and properties to be used as kiln lining in each specific zone to best counteract the severe thermal conditions. A cost-effective configuration was presented to assemble kiln lining for rotary kiln's different zones in line with the regulation at JC/T 2196-2013 "Specifications of refractory for cement rotary kiln". Chromite-free refractories with property of high endurance to thermal attack and corrosion are required to be used in modern Pre-calcining cement rotary kilns.     

Mössbauer studies of the corrosion reactions in arc-furnace refractories — Part II

Mössbauer spectroscopy has been used, together with conventional techniques, in the study of corrosion reactions taking place in service in co-clinkered chrome-magnesite bricks from the hot spots of an electric-arc furnace. Co-clinkered bricks present a better distribution of spinel phases than conventional bricks of similar composition. The Mössbauer data show that iron uptake took place in service, being incorporated only into the spinel structure. This structure accepts considerable substitutional ions, admitting in this case impurities from the slag. Experimental results confirm the relative stability of that phase in the presence of migrating components of the slag.     

水泥回转窑烧成带用耐火材料的最新研究

对水泥回转窑烧成带用耐火材料的使用条件和要求进行了分析,并对近年来水泥窑用镁铬砖、镁尖晶石砖、镁钙锆砖的应用进行了探讨,指出所存在的缺点及改进措施。认为其发展方向为镁钙锆砖及尖晶石砖,并对其应用前景进行了展望,希望实现水泥回转窑的无铬化。     

生产热风炉用硅质格子砖装车方法的改进

生产热风炉用硅质格子砖时,改变以往格子砖与其它砖型混装的装车方法,将其集中装于所选隧道窑窑车的二步炕部位,并对放砖方法进行了改进,不仅提高了格子砖的成品合格率,而且确保了其它砖型的成品率不受影响。     

大型回转窑筒体力学状态综合分析

利用有限元法计算回转窑筒体应力的分布状况。以中铝集团河南氧化铝厂3号窑为例,将筒体、衬砖及窑皮作为一个系统来研究,将筒体和衬砖分层分段建模,综合考虑了筒体、衬砖轴向的材质、厚度变化等因素,最终数值模拟了该窑筒体的应力分布状态。     

回转窑烧成带镁铬砖的使用与窑衬寿命的关系

根据回转窑烧成带镁铬砖的损坏机理，找出提高窑衬周期的具体措施，阐明水泥生产过程中回转窑烧成带镁铬砖的使用与窑衬寿命的关系。     

Method of determining strength of green refractories

Conclusions We designed and built an attachment for apparatus of the level type for determining the strength of the edges of unfired ceramic specimens under compression and shear.As a result of the studies made on the modernized apparatus we established that the green freshly shaped specimens made from currently used and modified materials, using strengthening agents, molded under a pressure of up to 150 MPa, do not possess compressive strengths or crimping edge strengths required for the formation of multicourse setting of goods on kiln cars, as with the use of chrome-magnesite and chamotte goods.Since, during the drying and firing of chamotte and chrome-magnesite refractories, certain articles are subject to damage, especially in the lower courses, then to make it possible to change over to loading of freshly molded dinas green brick onto kiln cars, the compressive and crimping strengths should be not less than 6 and 0.6 MPa.Translated from Ogneupory, No. 4, pp. 39–41, April, 1983.     

Refractories made from magnesite powder manufactured by the slurry process

Conclusions It was found under plant conditions that when magnesite slurry powder is used to make bricks, there is no longer any need to age them first, or any need for other methods of hydrating the free calcium oxide in the powder or charge.Magnesite slurry powder containing 86% MgO, 5% SiO₂ and 4.5% CaO can be used as a basis for making magnesite-chrome and chrome-magnesite bricks which come up to the required standards, provided the chromite ore contains a considerable proportion finer than 0.09 mm or a fine-ground mixture of chromite ore and magnesite powder.