水泥回转窑用碱性耐火材料显微结构的控制

根据显微结构特征分析研究了水泥回转窑用无铬碱性耐火材料的性能和发展。这些氧化镁基或白云石基材料,引入低膨胀性且抗侵蚀的加入物改善其显微结构。镁铝尖晶石砖是从直接加入粒状氧化铝、烧成过程中生成原生尖晶石,到直接加入预合成的尖晶石,发展至细粒晶型尖晶石再增强的含电熔尖晶石镁质砖;白云石砖以其良好的对水泥熟料的粘着性而被广泛用于水泥回转窑烧结带,加入氧化镁粉和氧化锆改善其基质增强了抗侵蚀性及抗热震稳定性;新发展的氧化镁-铁铝尖晶石和氧化镁-锰铝尖晶石耐火材料以其优越的柔性而被用于轮箍部位。     

水泥回转窑用含ZrO2耐火材料

含ZrO2耐火材料在水泥窑上的应用不断增加,水泥窑用含ZrO2耐火材料包括含锆白云石砖、含锆镁砖、含锆镁尖晶石砖、含锆高铝砖等.本文从材料的抗化学侵蚀性、热震稳定性、导热性和力学性能等方面讨论了ZrO2的引入对耐火材料使用性能的影响.     

Enhanced alkali vapor attack resistance of bauxite-SiC refractories for the working lining of cement rotary kilns via incorporation of andalusite

Bauxite-SiC refractories as the working lining of cement rotary kiln are subjected to severe alkali attack due to alternative fuel combustion. Herein, the present work aims to enhance their alkali attack resistance via incorporation of different types of andalusite (aggregates and powder). Results show that addition of andalusite reduces penetration of alkali vapor by decreasing their pore size. In particular, the presence of andalusite aggregate traps alkali vapor inside its pore network, retarding the corrosion of refractory matrix. By comparison, the presence of andalusite powder contributes to formation of liquid corrosion products to block the pores, which prevent alkali vapor from further penetration. Incorporation of andalusite into BSRs is straightforward and sought-after, providing an effective approach for high-performance refractory materials with excellent alkali attack resistance.     

活性石灰套筒窑煅烧带的材质选择

本文主要通过对几种耐火材料的热震稳定性、抗石灰侵蚀性和耐磨性能的实验和分析,以及对本钢活性石灰套筒窑煅烧带坍塌原因的分析,最终得出应该选择镁铝尖晶石材质的制品代替原来所用的纯镁质制品作为活性石灰套筒窑煅烧带的砌筑材料的结论。     

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。     

浅析红土镍矿回转窑整体窑炉技术的施工与应用

回转窑内衬可用耐火砖砌筑,也可选用其它的耐火材料做内衬,但是近几年,随着施工方法的改进及耐火材料研发的突破,回转窑内衬开始选用整体窑炉技术。将回转窑内衬的材料选用及施工工艺相结合,此方法可以提高回转窑产能,减少热损失,取得了高效节能降耗的显著效果。     

3300t/d回转窑稳态热分析及优化

应用数值模拟的方法,对中材建设有限公司在阿尔巴尼亚竣工的TITAN项目,建立了3300t/d、φ4.4m×65m新型干法水泥生产线回转窑系统窑皮、耐火砖、浇注料以及筒体等各部分的数学模型,并对它们相互间的热传递过程进行了模拟研究。结果表明,回转窑窑皮越厚,筒体表面温度越低,散失的热量越少;2号轮带两侧筒体表面温度比3号轮带的高,为防止轮带变形及更大的热膨胀,应适当增加该处冷却风机的风量;2号轮带附近靠向窑尾一侧的筒体表面温度较高,建议增加两台冷却风机;当正常连续生产中窑皮厚度相对稳定时,可以适当减少冷却风机的个数,降低电耗,若停开4台筒体冷却风机,可每天节省用电720kWh。     

Present Synthesizing Situation and Application Mechanism of Hercynite in Cement Kilns

The magnesia-hercynite bricks offer a new lining to rotary cement kiln. They are well adopted and widely used in the high temperature zone of cement kiln, and have obtained good performance at rigorous and severe working conditions. The synthesis of hercynite requires a suitable atmosphere with proper O2 partial pressures which makes sure FeO can stably exist at the synthesizing temperature. Current industrial production of hercynite mainly adopts fused method. The other method, sintering method, is not mat...     

有色金属火法冶炼用耐火材料及其发展动向

根据近些年来有色重金属与轻金属火法冶炼工艺技术的发展,从有色重金属与轻金属火法冶炼条件的特点分析与阐述了所用耐火材料发展的动向,着重介绍了有色金属冶炼炉如:闪速炉、澳斯麦特炉、艾萨炉、诺兰达炉、转炉、连续炼铜炉、氧气底吹熔池直接炼铅炉(QSL炉)、铅锌密闭鼓风炉(ISP炉)、粗锌精馏炉、锌浸出渣挥发回转窑、碱石灰法回转窑、焙烧炉、铝电解槽、铝熔化炉以及硅热还原法制原镁等窑炉关键部位所用的耐火材料。另外,为了给上述冶炼炉的关键部位选择合适的耐火材料,还对一些耐火材料组元的抗FeO-SiO2渣侵蚀,抗炉渣与锍的渗透以及在炉衬工作面形成保护层等方面进行了分析与论述。此外,化学热力学计算与现场试验结果表明,含碳耐火材料不适宜用在重有色金属冶炼炉。还介绍了不同品种的镁铬耐火材料与碳化硅质耐火材料以及Al2O3-Cr2O3-尖晶石材料,并对含Cr2O3耐火材料存在的问题与解决途径做了分析与建议。     

Effect of alkalis on alumina refractories in cement rotary kilns

Causes of failure of the refractory lining of a cement rotary kiln are investigated for specimens taken from the preliminary firing and decarbonizing zone. It is established that at temperatures above 1400°C sodium-aluminum silicates are formed on the hot surface of the refractories and an increased content of alkali leads to the formation of compounds of the feldspar group.Translated from Ogneupory, No. 6, pp. 21–25, June, 1995.     

Corrosion of Disposing Urban Domestic Wastes on Refractories for Cement Rotary Kilns

Corrosion of burning urban domestic wastes to alkali-resistant bricks and spalling-resistant high alumina bricks was researched by static crucible method and SEM in order to choose refractories for cement rotary kilns for collaboratively disposing wastes. The result indicates that the main corrosion mechanism is slag permeation and corrosion; the emitted high temperature gases containing alkali,sulfur and chlorine during burning the wastes react with refractories forming low melting point sulfate,chloride and compound salts,which metamorphose the refractories,and the loose metamorphic layer is easy to spall under thermal stress. So,corrosion resistance and spalling resistance shall be taken into account when choosing refractories for cement rotary kilns for collaboratively disposing wastes. It is suggested that decomposition furnaces should adopt spalling resistant high alumina bricks and anti-coating Si C castables,and preheating equipment should adopt high strength alkali-resistant bricks and castables.     

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。     

耐火材料及二级窑壳在降低水泥窑表面热损失方面的应用情况

水泥生产过程中主要热量损耗在于窑尾预热器出口废气带走热、窑系统表面向环境通过辐射及对流方式传导热量、窑头熟料冷却机余风带走热和出冷却机熟料带走热损失等.研究水泥窑尾预热器表面耗散热和回转窑筒体热回收技术,是提高水泥厂能量利用率的重要措施.为了在预分解窑更高效的使用能源审计分析.本文从能量平衡的角度分析了预分解窑系统的能源利用及损失情况,研究了耐火材料降低预热器筒热损失及利用二级窑壳回收回转窑表面余热的情况,提高水泥窑系统的能源利用率.     

Lightweight design of bauxite-SiC composite refractories as the lining of rotary cement kiln using alternative fuels

To meet the demand of energy-saving and adapt to the change from coal to the alternative fuel in the rotary cement kiln, bauxite-SiC refractories were fabricated by the incorporation of silica sol coated lightweight mullite aggregates in order to achieve low thermal conductivity and superior alkali vapor attack resistance simultaneously. Furthermore, the mechanism of resistance to alkali vapor attach was investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that the thermal conductivity of bauxite-SiC specimens decreased gradually with increasing amounts of silica sol coated lightweight mullite aggregates while changes in the alkali vapor attach were not detectable. The shell-covered structure with a silica sol coating on the surface of lightweight aggregates hindered alkali vapor diffusion into the aggregates at high temperature. Bauxite-SiC refractories possessed lower thermal conductivity, superior alkali attack resistance and higher mechanical properties compared with the specimens which contained pristine lightweight aggregates.     

Composition and microstructure of a periclase–composite spinel brick used in the burning zone of a cement rotary kiln

The composition and microstructure of a periclase–composite spinel brick used in the burning zone of a cement rotary kiln were investigated and compared to the original brick. The results indicate that cement clinker and alkali salts are two important agents that cause corrosion especially of the bonding phase of refractories in cement rotary kilns. When the molar ratio of alkalis to anions ((Na+K)/(Cl+2S)) is more than one, alkali salts accumulated in the pores, cracks and grain boundaries of the refractory but the severe corrosion of the bonding phase of the refractory did not occur in zones with lower temperatures. The interaction between the cement clinker and the refractory formed a liquid, which, together with alkali salts, improved sintering. The reaction between the cement clinker and the refractory formed a dense reaction layer. Cracks formed in the dense layer and extended through the boundary between the reaction and non-reaction (penetrated) layers by mechanical and thermal stress, which caused the spalling of the reaction and coating layer from the refractory. The recurrence of this process during service leads to degradation of the refractory.     

ZrO2—Containing Refractories for Cement Rotary Kilns

ZrO2-Containing Refractories have been increasingly used for cement rotary kilns,This paper discusses how the properties and performance of ZrO2-Containing Refractories are improved in terms of chemical attack resistance,thermal shock resistance,thermal conductivity and mechanical stress.     

大型干法水泥回转窑过渡带用镁铝尖晶石砖的损毁机理

对5000t.d-1的大型干法水泥回转窑过渡带用后镁铝尖晶石砖(LMLJ-80)分别进行了外观观察及物理性能、XRD、SEM和EDAX等分析,探讨了其损毁机理。研究结果表明:水泥熟料对镁铝尖晶石砖的侵蚀不是其损毁的主要原因,而碱盐的沉积和热震综合作用下的结构剥落和热剥落是过渡带用镁铝尖晶石砖损毁的主要形式。因此,提高镁铝尖晶石砖的韧性和抗剥落性是提高炉衬寿命的重要措施之一。     

煅烧石油焦回转窑内衬技术分析及改进措施

通过测试和实际使用研究,对原有的煅烧焦回转窑内衬进行分析,并进行了一系列的改进,使得煅烧回转窑内衬的使用寿命得到显著提高,改造后的煅烧回转窑,连续生产稳定性大大提高,耐火内衬寿命显著延长,大大降低了频繁停窑检修的成本。     

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。     

活性石灰回转窑内衬复合砖的研制与应用

针对活性石灰回转窑在运行中存在内衬砖使用寿命短、隔热效果不好导致炉壳过热的问题,开展了回转窑内衬耐火材料的研究。通过破损调查和配方试验,研制了耐高温工作层与保温层一体成型的复合结构预制砖,使回转窑内衬的使用寿命提高到2年以上,降低炉壳表面温度50℃以上。