铝矾土和锆英石合成ZrN-SiAlON及其在含碳耐火材料中的应用研究

发布时间：2018-04-05 05:03

本文选题：铝矾土　切入点：锆英石　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：针对开发利用中低品位铝矾土等耐火资源和新型低碳非氧化物复相耐火材料的性能优化等问题,本文利用中低品位铝矾土和锆英石制备ZrN-SiAlON等复相耐火粉体,并以蔗糖为结合剂,结合SiC粉体,制备含碳耐火材料,研究其力学性能、抗氧化性能和抗渣侵性能,取得一些重要研究成果。分析中低品位铝矾土和锆英石通过碳热/铝热还原氮化法合成ZrN-SiAlON耐火原料的物相行为,获得优化的工艺参数。采用焦炭作为还原剂时,中低品位铝矾土和锆英石在1600°C合成较纯的ZrN-SiAlON物相。以ZrN-SiAlON耐火粉体为基质,以蔗糖溶液为结合剂,结合SiC粉体制备ZrN-SiAlON-SiC-C复相非氧化物耐火材料。经1500°C热处理后,ZrN-SiAlON耐火粉体受到蔗糖热分解的影响,物相变化生成ZrO2、刚玉和石英,导致体积发生膨胀,显气孔率变大,体积密度减少,当ZrN-SiAlON耐火粉体添加量为40wt.%时,其显气孔率达到最大,体积密度达到最低,常温抗折强度达到最大,分别为53.23%,1.36g/cm3,4.39MPa,但ZrO2、刚玉和石英的含量升高,有助于提高ZrN-SiAlON-SiC-C复相耐火材料的抗折强度。通过研究ZrN-SiAlON-SiC-C复相耐火材料的氧化行为变化,结果表明该材料在氧化过程中质量变化主要受到不定形碳和SiC粉体的氧化。另外,当氧化温度为1200°C时ZrO2和方石英反应生成锆英石,当氧化温度为1400°C时,刚玉和方石英生成莫来石。通过研究气氛环境对ZrN-SiAlON-SiC-C复相耐火材料抗渣侵性能的影响,结果表明,在氧气氛围,该耐火材料氧化严重,造成孔隙变大,渣侵蚀严重。在氩气氛围,高炉渣渗透到耐火材料中,并溶解耐火材料,然后不断渗透,填充耐火材料孔隙,形成致密层。在还原氛围,高炉渣对耐火材料的润湿角变大,没有发生侵蚀现象。
[Abstract]:Aiming at the problems of developing and utilizing refractory resources such as medium and low grade bauxite and new low carbon non-oxide composite refractories, this paper prepared ZrN-SiAlON and other multiphase refractory powders with sucrose as binder, using medium and low grade bauxite and zircon as binder.Carbon-containing refractories were prepared with SiC powder, and their mechanical properties, oxidation resistance and slag erosion resistance were studied, and some important research results were obtained.The phase behavior of medium-low grade bauxite and zircon in the synthesis of ZrN-SiAlON refractory by carbothermal / aluminothermic reduction nitridation was analyzed and the optimized process parameters were obtained.When coke is used as reducing agent, relatively pure ZrN-SiAlON phase is synthesized from bauxite and zircon at 1600 掳C.Using ZrN-SiAlON refractory powder as matrix, sucrose solution as binder and SiC powder as binder, ZrN-SiAlON-SiC-C multiphase non-oxide refractories were prepared.After heat treatment of 1500 掳C, ZrN-SiAlON refractory powder was affected by the decomposition of sucrose, resulting in the formation of ZrO _ 2, corundum and quartz, resulting in volume expansion, increasing apparent porosity and decreasing volume density. When the amount of ZrN-SiAlON refractory powder was 40 wt.wt%,The apparent porosity, bulk density and flexural strength of ZrN-SiAlON-SiC-C multiphase refractories were 53.23, 1.36 g / cm ~ 3 and 4.39 MPa, respectively, but the contents of ZrO _ 2, corundum and quartz were increased, which was helpful to improve the flexural strength of ZrN-SiAlON-SiC-C multiphase refractories.The oxidation behavior of ZrN-SiAlON-SiC-C multiphase refractories is studied. The results show that the mass changes of ZrN-SiAlON-SiC-C composites are mainly oxidized by amorphous carbon and SiC powders during the oxidation process.In addition, when the oxidation temperature is 1200 掳C, ZrO2 reacts with cristobalite to form zircon, and when the oxidation temperature is 1400 掳C, corundum and cristobalite form mullite.The effect of atmosphere on slag erosion resistance of ZrN-SiAlON-SiC-C multiphase refractories was studied. The results showed that in oxygen atmosphere, the refractory was oxidized seriously, resulting in larger porosity and serious slag erosion.In argon atmosphere, blast furnace slag infiltrates into refractories, dissolves them, and then penetrates continuously, filling the pores of refractories to form dense layers.In reducing atmosphere, the wetting angle of blast furnace slag to refractory becomes larger, and no erosion occurs.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ175.1

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