【作者】 钟莲云；

【导师】 吴伯麟； 张联盟；

【作者基本信息】 武汉理工大学 ， 材料科学与工程， 2006， 博士

【摘要】 生态环境材料是指同时具有满意的使用性能和优良的环境协调性或者能够改善环境的材料。耐火材料废料低的回收利用率给环境保护带来了极大的压力；我国对Al₂O₃瓷球的需求量巨大，但Al₂O₃原料涨价使高铝瓷球的生产利润很低，很多厂家被迫停产或倒闭，急需实现高铝瓷球低成本高档化，以满足市场需求。本论文主旨是探索研究用硅酸铝质耐火材料废料制备性能优良的工业陶瓷的可行性。以瓷球作为研究的切入点，以耐火材料废料为主要原料，天然矿物为助熔剂，通过合理设计晶界相的组成，成功地制备了一系列性能优异的、Al₂O₃含量从45％至85％的氧化铝基瓷球，并详细研究了各工序的物化过程及规律及其与制成产品的性能、结构及特征的关系。对制备工艺及助熔剂对陶瓷的烧成及性能影响的研究结果表明，在瓷球组分构成的CaO-MgO-Al₂O₃-SiO₂、MgO-Al₂O₃-SiO₂和CaO-Al₂O₃-SiO₂三个体系中，CaO-MgO-Al₂O₃-SiO₂系瓷球的烧成温度最低，烧成温度范围最宽；CaO-Al₂O₃-SiO₂系瓷球的耐磨性最好，CaO-MgO-Al₂O₃-SiO₂系陶瓷的耐磨性次之，而MgO-Al₂O₃-SiO₂系瓷球的耐磨性最差；在CaO-MgO-Al₂O₃-SiO₂和CaO-BaO-Al₂O₃-SiO₂两个体系制备瓷球的主晶相均为莫来石，次为刚玉和钙长石，但CaO-BaO-Al₂O₃-SiO₂系瓷球的烧成温度低、玻璃相的含量和密度高、结构较致密、耐磨性好；延长废料的球磨时间，废料的粒度减小，所制备瓷球的烧成温度降低、密度和耐磨性提高、晶粒尺寸和气孔率降低，瓷球在磨损过程中穿晶断裂的比例增加；延长干坯料的存放时间，坯料的性质趋于均匀化，所制备瓷球的耐磨性提高；增加坯体的成型压力可降低瓷球的烧成温度、拓宽烧成温度范围并提高耐磨性；研究了陶瓷的组成、结构与其性能的关系，首次发现Al₂O₃含量低于60％的陶瓷具有高的耐磨性且其耐磨性随着Al₂O₃含量的降低、堇青石含量的增加而增加的规律；陶瓷的主晶相与所用耐火材料废料的主晶相相同，且主晶相的含量随着Al₂O₃含量的增加而增加；获得用耐火材料废料制备陶瓷的烧结反应机理：大颗粒起到骨架作用，小颗粒在烧结过程中的熔解、结晶完成烧结；发现粗晶粒陶瓷可具有高的耐磨性；提出在瓷球磨损表面形成晶体破坏层，并从证实了瓷球的穿晶断裂磨损机理；当氧化铝含量大于60％时，陶瓷的密度和耐磨性均随着氧化铝含量的增加而提高；陶瓷的抗弯强度、断裂韧性和耐磨性随着晶粒粒径、气孔率和气孔直径的减小而增加；Fe₂O₃含量增加，陶瓷的烧成温度降低，密度和耐磨性提高，但陶瓷的颜色也随着Fe₂O₃含量的增加而加深；TiO₂、CaO、K₂O和Na₂O的含量增加也使陶瓷的颜色加深。揭示了瓷球的磨损率既正比于瓷球的作用压力又正比于瓷球间的接触点数的规律；通过理论推导和试验验证，建立了瓷球磨损率与其大小之间的关系模型：w=ar^-1／3／t+b，该模型较现有模型简明、合理，而且瓷球的性能越高，模型的预测结果越准确，证实了陶瓷的性能越高，其优异性能的重现性越好、可靠性越高。利用创新的自分散技术，探索了用半湿化学法制备陶瓷的可行性，并获得若干有价值的结果。采用半湿化学法制备，可降低瓷球的烧成温度，提高其耐磨性；随着纳米AlOOH粉加入量的增加（当加入量低于3.5％时），瓷球的烧成温度降低，密度和耐磨性提高；次晶相在晶界的均匀分布使晶界结合牢固，有利瓷球实现穿晶断裂。在相同条件下测试时，制备的含75％Al₂O₃瓷球的磨损率为0.0188％，含85％Al₂O₃瓷球的磨损率为0.0124％，而建材行业用国际最高水平95瓷球的磨损率为0.0523％／h。不仅如此，本研究获得的瓷球还有极优的性价比和原料的优势和广泛性。更多还原

【Abstract】 Ecological Environmental Materials is the materials with excellent performance and enviromental compatibility or improvment. The low recycle ratio of refractory waste leads to the increase of enviroment protection difficulty. China is the largest ceramic production country and large quantity of alumina ceramic balls are used to mill ceramic raw materials annually. The high alumina ceramic ball extremely low profit because of the continuous increasing of alumina raw materials made many factories to stopping produce or bankruptcy. At present, it become urgent to produce high perforamance high alumina ceramic balls in low cost to meet the factory demand.In this paper, aluminosilicate refractory waste with 60%～90% Al₂O₃ was first recycled to prepare high performance industrial ceramic. Ceramic ball was prepared first as an example. The physical and chemical reaction during preparing and the relation between the preparation processes and the products performance, structure and character were studied. High performance alumia ceramic balls with 45%～85% Al₂O₃ were prepared in CaO-MgO-Al₂O₃-SiO₂ quaternary system by using aluminosilicate refractory waste as raw materials and natural mineral as fluent agents, designing the crystal boundary phase and sintering by low temperature and fast sintering technology in air. The relation between ceramic performance, structure and characteristics and process conditions were studied in detail.The ceramic were prepared in the three systems of CaO-MgO-Al₂O₃-SiO₂ （ceramic was name as CMAS）, MgO-Al₂O₃-SiO₂（ceramic was name as MAS）, CaO-Al₂O₃-SiO₂（ceramic was name as CAS）.The sintered temperature of CMAS was the lowest and the sintered temperature range was the widest. The wear resistance of CAS was the highest and MAS was the lowest. The crystal phase of CMAS and CBAS （the ceramic prepared in CaO-BaO-Al₂O₃-SiO₂ system）were the same as mullite, corundum and anorthite. Compared with CMAS, CBAS sintered temperature was lower, glass content was higher resulting in higher density, denser structure and higher wear resistance.Refractory waste particle size decreased with the increase of milling time, leading to lower sintered temperature, particle size and porosity and higher density and wear resistance and the ratio of transcrystal fracture of the as-prepared ceramic ball. The ceramic wear resistance increased with the storage time of the used ceramic blank increasing because of the uniform of the blank property. With the increase of ceramic body forming pressure, the prepared ceramic ball sintered temperature decreased, sinter temperature range and wear resistance increase.In the present dissertation, the high wear resistance of the ceramic with Al₂O₃ lower than 60% and the wear resistance increased with the increase of Al₂O₃ and cordierite were explored. Ceramic crystal phase were the same as the used refractory waste and increased with ceramic Al₂O₃ increasing. The sintered mechanism of the ceramic prepared by the refractory waste was that large particle acted as frame and small particle melt into melt then crystalized from the melt during sintering. The ceramic with corse crystal may have high wear resistance as prepared in suitable conditions. It was found on the ceramic ball milled surface a layer formed by the ceramic crystal with partial broken away indicating that high ratio of transcrystal fracture wear mechanism was occur during milling. The ceramic density and wear resistance increased with the increase of ceramic Al₂O₃ as Al₂O₃ higher than 60%. Ceramic fracture strength, fracture toughness and wear resistance increased with the decrease of crystal size, porosity and pore size. Ceramic sintered temperature decreased, density and wear resistance increased with the increase of the ceramic Fe₂O₃ content, however the ceramic color darkened with the increase of Fe₂O₃ too. The ceramic color also darkened with the increase of ceramic TiO₂, CaO, K₂O, Na₂O.The relations that ceramic wear rate directs proportion to the pressure acted on ceramic ball and the contact points between ceramic balls were explored. A concept simple model of ceramic wear rate and size: w=ar^-1/3/t+b was developed. Compared with the existed models, the developing model is simpler and more rational. The higher the ceramic performance, the accurater results the model report, proving that the higher the ceramic performance, the higher the ceramic reproduction and reliability.A self dispersion technology was developed. The possibility of preparing ceramic by half wet chemical method using self dispersion technology was studied and several results were obtained. First was that ceramic sintered temperature was lower and wear resistance was higher, second was that ceramic sintered temperature decreased and density and wear resistance incereased with the increase of nano AlOOH powder in ceramic body （as AlOOH lower than 3.5%）. The secondary crystal phase distributed uniformly in crystal boundary increased the binding strength of crystal boundary, leadding to the increase of transcrystal fracture.Tested in the same conditions, the wear rate of the preapred ceramic ball with 75% Al₂O₃ was 0.0188% and with 85% Al₂O₃, was 0.0124%, while the wear rate of the world best 95 ceramic ball was 0.0523%/h. Furthermore, the ceramic ball prepared in this dissertation exhibits higher ratio of performance to price, raw materials predominance and extensive.更多还原