水泥回转窑烧成带用无铬砖的开发

介绍了水泥回转窑用镁铬砖的优点和缺点，指出了镁铬砖在使用中生成有害的六价铬盐对环境和人体的危害，并通过在日本旭玻璃公司和日本三菱材料公横濑厂等的水泥回转窑烧成带和窑箍部位使用无铬砖取得的成绩，提出了在水泥回转窑上实现全部无铬化的目标。同时还具体介绍了镁－尖晶石砖、镁－铁尖晶石砖等无铬砖的性能和实际使用效果。     

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。     

水泥回转窑烧成带用耐火砖的无铬化

1前言 近年来，要求减轻水泥回转窑内衬耐火材料对环境的负担。以前日本水泥窑烧成带基本使用镁铬砖，主要是通过应用镁尖晶石质无铬砖，在包括燃烧带的烧成带全部区域顺利地推进无铬化。本文介绍水泥回转窑燃烧带无铬砖的使用效果和应改善特性之一的低导热性的研究结果。     

水泥回转窑烧成带用无铬砖的使用效果

在水泥回转窑中，希望消除剩下的使用镁铬砖的区域，尽快实现全部无铬化。多数无铬砖是镁尖晶石砖(以下称尖晶石砖)的改进产品，镁铬砖的使用区域逐渐减少，剩下的区域主要是中心烧结区附近和窑箍部位。     

MgO-TiO2-Al2O3系原料在无铬耐火材料上的应用

水泥窑多数使用镁铬砖，镁尖晶石砖也作为无铬材质使用，但并未完全实现无铬化。从环境的角度出发，特别希望有铬的替代原料，所以此次对MgO-TiO2-Al2O3系原料(以下简称MTA)能否作铬的替代原料进行了研究。同时还研究了能否替代尖晶石原料，并由此研究了MTA原料能否应用于水泥窑耐火材料上。     

水泥窑用耐火材料及其选择匹配

水泥窑用耐火材料有粘土砖、高铝砖、磷酸盐结合高铝质窑衬砖、镁砖、镁铝尖晶石砖、普通镁铬砖、直接结合镁铬砖等等，根据它们不同性能分别匹配于窑系统的不同部位。     

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     

水泥回转窑用无铬砖的演变

介绍了日本国内外水泥回转窑用耐火材料的演变和最近无铬砖的开发使用情况。目前无铬砖有白云石砖、镁尖晶石系无铬砖、铁尖晶石系无铬砖、镁钙锆系无铬砖等，其中Mgo—CaO-ZrO2系无铬砖具有与镁铬砖同等以上的性能。今后，无铬砖将象镁铬砖一样，可在水泥回转窑烧成带任何部位上使用。     

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。     

水泥回转窑用碱性砖的无铬化

1 前言 从保护地球环境和构筑资源循环型社会的观点来看,水泥回转窑起着重要的作用,也要求窑衬耐火材料对环境必须是安全的。水泥回转窑用碱性砖的无铬化进展顺利,随之抗水化性等应改善的特性也显现出来。2 无铬碱性砖的种类和特性 ①镁钙锆质砖(种类1)的耐熔损性优于镁铬质砖(以下称镁铬砖),挂窑皮附着性和稳定性良好。 ②使用特殊砂、添加氧化锆的镁尖晶石质砖(种类2)由     

The State—of—art of Magnesia—chrome Refractories for P—S Converter in China‘s Non—ferrous Industry

The state-of-art of magnesia-chrome refractories from direct-bonded magnesia chroma brick to fused-grain rebounded magnesia chrome brick for P-S converter is discribed.The Cr2O3 conternt of the brick is continually increased with the reduction of the impurity content of brick ,the pre-synthetic raw material is applied and the operating condition of conerter is optimized so that the service life of converter is largely enhanced.     

水泥窑用优质镁铬砖的试制与生产

以烧结好的中档镁砂作骨料，普通电熔镁砂作细粉，同时控制普通铬矿的临界粒度为２ｍｍ可以生产出优质镁铬砖，其技术指标达到或接近直接结合镁铬砖，且生产工艺简单，成本低，便于生产     

Corrosion Resistance Mechanism of Magnesia Zirconia Brick to RH Furnace Slag

Magnesia zirconia brick containing 11 wt% zirconia was prepared with magnesia and monoclinic zirconia as starting materials in order to replace the chrome-containing materials for RH furnace.The corrosion resistance of magnesia zirconia brick and fused rebonded magnesia chrome brick (short for magnesia chrome brick) to high and low basicity slag of RH furnace was comparatively researched by rotary slag method and their slag resistance mechanisms were analyzed.The results show that:(1) because the reaction l...     

水泥窑用高性能镁铬砖的研制及应用

分析了普通镁铬砖在水泥窑上使用存在的不足之处。在原来普通镁铬砖工艺基础上引入特制的合成料,使制品的性能得到改善。高性能镁格砖在水泥窑上使用,寿命远远超过普通镁铬砖。     

TiO_2对镁铬砖抗渣蚀性的影响

利用XRD分析和光学显微镜等测试手段 ,研究了添加TiO2 对镁铬砖抗渣蚀性的影响。结果表明 :炉渣中的CaO能分解镁铬砖中的二次尖晶石而使镁铬砖损毁 ,但加入TiO2 后 ,TiO2 能优先于尖晶石中的Cr2 O3与渣中CaO反应 ,生成高熔点的CaTiO3,从而抑制CaO对砖中镁铬尖晶石的分解 ,提高了镁铬砖的抗高钙渣渣蚀能力     

回转窑烧成带用镁铁铝尖晶石砖的研制与应用

以新理论、新工艺合成出了结晶完好、质地均匀的铁铝尖晶石,并以合成的铁铝尖晶石为原料制备了镁铁铝尖晶石砖。大量应用结果表明,研制的镁铁铝尖晶石砖具有窑皮形成迅速、稳定、导热率小及使用寿命长等优点,总体性能超过了镁铬砖,满足了大型回转窑烧成带的无铬化要求。     

Characteristics of Hercynite and Its Application in Refractories

The characteristics of hercynite including crystal structure,chemical compositions and physical properties, R D background of hercynite,synthesis problems of hercynite,and roles of hercynite in refractories were reviewed. The application of hercynite in refractories was introduced with emphasis. The practical applications in cement rotary kiln showed the prepared magnesia hercynite brick had better performance than the original magnesia chrome brick obviously.     

镁铁铝尖晶石耐火砖安全运行两年使用经验

镁铁尖晶石耐火砖替代直接结合镁铬耐火砖,降低Cr6+对环境的影响,但其导热系数大,挂窑皮性能差等缺点,造成使用周期短,筒体温度高和红窑等问题。采用镁铁铝尖晶石耐火砖,兼顾镁铁尖晶石和镁铝尖晶石的优点,优化砖的实物质量和窑内配砖是基础,窑皮维护是关键。日常生产中要关注结皮值,做到窑皮平整,避免结圈结蛋等工艺事故。同时关注升温、降温过程,及浇注料和煤管运行状态,均可提高窑内烧成带的耐火砖的使用周期。     

高基质普通烧镁砖的研制及应用

在普通烧镁砖中,提高基质相原料纯度,可使精炼铬铁炉炉衬寿命明显提高。     

Three bond modes of basic refractories used for Ruhrstahl Heraeus degassing process

Magnesia–spinel brick and unburnt periclase–spinel–Al brick are being employed as a substitution of traditional magnesia–chrome brick in the chromium-free campaign of lining materials in Ruhrstahl Heraeus (RH) degasser. These three materials are investigated, in terms of physical properties, corrosion resistance and flexibility by wedge splitting test. Tracking their physical alterations and chemical reactions through burning or heating, three bond modes are discovered. Magnesia–chrome brick is subject to a series of phase transformation with rising temperature to yield a liquid envelop around chromite-ore particles, to further form porous rim while liquid is gradually absorbed by surrounding magnesia and eventually to precipitate secondary chromite spinel lied between magnesia particles by thoroughly dissociating chrome ore. The precipitated chromite spinel functions as the featured bond that enhances hot strength and corrosion resistance to slag, and additionally liquid coexistence improves the flexibility. The direct bond mode of magnesia particles in magnesia–spinel brick endures slag penetration by immanent character of MgO. Spinel incorporation in magnesia effectively improves thermal shock resistance. Due to minor negative value of permanent linear change after reheating, further sintering (densifying) in using at high temperature would bring a risk of loosening and open joints of magnesia–spinel lining. While used in RH degasser, unburnt periclase–spinel–Al bricks undergo a miraculous process of metallic Al melting, gaseous AlN and AlON formation, MgAlON whiskers germination combined with gaseous Mg reduced, and micron-size whisker network bond domination in their matrix. Such a whisker-network bond renders the material a successful eco-friendly alternative to magnesia–chrome refractory.