【作者】 赵军；

【导师】 王宏联； 薛群虎；

【作者基本信息】 西安建筑科技大学 ， 材料学， 2007， 硕士

【摘要】 二十世纪七十年代以来，随着世界范围内环保意识的加强和发展绿色工业的要求，国外水泥窑用碱性耐火材料已发生了近乎根本性的转变。引发这种转变的主要原因是消除“铬公害”来保护人类的生存环境。作为水泥窑用关键材料—镁铬砖，使用过程中在碱和硫的作用下，生成水溶性的且能毒害人畜并致癌的六价铬盐化合物R₂Cr（Ⅵ）O₄和R₂[SCr（Ⅵ）]O₄等有害化合物，通过水泥窑的废气和粉尘排放，尤其是用后残砖在存放过程中受水淋溶出而外渗污染环境，特别是污染水源，导致适合水泥窑用的镁铬砖开始在发达国家逐步逐出历史舞台。镁铬砖最早出现的替代品是镁白云石砖。镁白云石砖对水泥熟料具有亲和性且化学稳定性好，从而具有良好的挂窑皮性，但其存在着易水化和抗热震性差的缺点。取代镁铬砖的尖晶石砖具有优良的抗热震稳定性，但其在使用时不能形成稳定的窑皮，而且热导率高，导致这两种砖都不能够完全替代镁铬材料在水泥回转窑上的使用。本研究课题采用95烧结镁砂，96电熔镁砂，单斜氧化锆，锆英砂（ZrO₂·SiO₂），Zr（OH）₄凝胶等作为原料，进行了水泥窑用镁锆质耐火材料的研究。实验结果表明：以96电熔镁砂为细粉配以95电熔镁砂作为颗粒制作的试样性能优于以95烧结镁砂细粉配以95电熔镁砂作为颗粒的试样。而在ZrO₂的三种引入方式中，引入单斜氧化锆的试样抗水泥熟料侵蚀性最好，而挂窑皮性最差；引入锆英砂的试样虽然其挂窑皮性很好，但抗侵蚀性是最差的。综合考虑：引入Zr（OH）₄凝胶的试样性能最好，其抗压和抗折强度也是最高的。此研究成果对我国水泥窑用耐火材料无铬化具有一定的理论指导作用和生产使用价值。更多还原

【Abstract】 From the end of 1970s, because of the improvement of environmental protection and the need of development green industry, there are great changes have happened to the basic bricks used in cement rotary kiln. The cause of the change is elimination of chrome — pollution and protection of human living environment. As the key refractory in the burning zone of the cement rotary kiln, the Magnesia — chrome bricks form the water — soluble compound R₂Cr（VI）O₄ or R₂[SCr（VI）]O₄ which are harmful for human being and animals under the action of alkali and sulfur . The poisoned compound could be compelled through the wasteful gas and dust. The bricks that had been used suffer the rain and the poisoned compound could pollute environment, specially the water. The Magnesia — chrome bricks are gradually limited in developed countries, and would be instead.The first material instead of the magnesia — chrome bricks is Magnesia — dolomite bricks. The Magnesia — dolomite brick has the appetency and good stability of chemistry, which result in the superior coating adherence and corrosion resistance to cement raw materials. It also has the disadvantages of hydration and bad thermal — shock resistance. Spinal brick has the good thermal — shock resistance, however it has the disadvantages such as the bad coating adherence and high heat — conducting rate. All these disadvantages cause they could not completely instead of the Magnesia — chrome bricks which is used in the sinter-zone of the cement rotary kiln.We use 95 sintered magnesia, 96 fused magnesia, c-ZrO₂, Zircon （ZrO₂·SiO₂）, Zr（OH）₄gel as the raw material for the research of MgO-ZrO₂ series refractoriness in sinter zone of cement kiln. The experimental result is: the specimens that is made up of 96 fused magnesia fine power and 95 fused magnesia grain is better than the specimens which is made up of 95 sintered magnesia fine power and 95 fused magnesia grain. In the three additive ways of ZrO₂ the cement corrosion resistance of the specimen which is addicted with C-ZrO₂ is the best, and the cement adherence is the worst;however the specimen which has the best cement adherence, its cement corrosion resistance ability is the worst. Thus according to the experimental phenomenon, we can gain the conclusion: the performance of the specimen that is addicted with Zr（OH）₄ gel is better, its compressive strength and the fold strength are high. What we had researched makes a useful attempt in the procession of free chrome for cement refractoriness in china. And it also have guideing function for theory and value in use for production in the procession of free chrome for cement refractory in china.更多还原