【作者】 杨林；

【导师】 廖立兵；

【作者基本信息】 中国地质大学（北京） ， 岩石矿物材料学， 2011， 博士

【摘要】 本文针对目前炼铁高炉出铁沟对高性能、低成本、长寿命耐火材料的需求,采用易得的叶蜡石、金红石、焦炭为主要原料,通过碳热还原以及碳热还原氮化工艺合成Al2O3-SiC-TiNC和Sialon-TiNC复相粉体材料。利用热力学分析、XRD、SEM、EDS等手段系统研究相关工艺因素对还原产物物相的影响,探讨Al2O3-SiC-TiNC和Sialon-TiNC复相粉体材料的抗渣侵蚀性,制备了含Sialon-TiNC的高性能Al2O3-SiC-C质新型铁沟浇注料。对不同气氛(埋炭条件；流动氮气条件)、不同配碳量(理论量、过量10%、过量50%、过量100%)、不同还原温度(1300～1600℃；1400～1550℃)和不同金红石配比量对产物物相及微观形貌的影响进行了研究。结果表明：埋炭和焦炭过量100%在1600℃保温4h条件下金红石配比量为10%的产物中主物相为刚玉、β-SiC、TiN0.3C0.7;流动氮气气氛下,焦炭过量50%在1500℃保温4h时金红石配比量为10%的产物中主物相为β-Sialon、TiN0.7C0.3。较高的反应温度和配碳量的增加能促进产物中β-SiC和β-Sialon发育完全；适量金红石配比量(10%)有利于β-SiC和β-Sialon生成,生成的TiNC (TiN0.3C0.7或TiN0.7C0.3)有助于提高试样的抗渣侵蚀能力。进行了Al2O3-SiC-TiNC和Sialon-TiNC复相粉体材料的抗渣侵蚀性能的研究,结果表明：不同Ti含量的Al2O3-SiC-TiNC和Sialon-TiNC材料均表现出了较好的抗渣侵蚀能力,生成的TiNC (TiN0.3C0.7或TiN0.7C0.3)对试样的抗渣性能具有增强作用。金红石添加量10%的试样具有较优的抗渣侵蚀性能和抗氧化性能。研究了Sialon-TiNC添加量(0、3%、6%、9%、12%)对Al2O3-SiC-C质铁沟料常温物理性能、抗氧化性能及抗渣侵蚀性能等的影响。实验结果表明：添加Sialon-TiNC的Al2O3-SiC-C质铁沟浇注料抗氧化性能和抗渣侵蚀性能均有不同程度提高,Sialon-TiNC添加量为6%的试样具有较优的抗氧化性能,1450℃热处理后氧化层厚度为2.77mm,而未添加Sialon-TiNC试样的氧化层厚度为5.16mm；Sialon-TiNC能阻止高炉渣对浇注料的渗透侵蚀；同时Sialon-TiNC添加量为6%时,试样低温(110℃×24h)和高温抗折强度分别达最高值7.75MPa和7.35MPa,耐压强度达29.53MPa和31.83MPa；1450℃热处理后线变化率仅为0.01%,气孔率13.86%,体积密度2.84g/cm3。在本实验研究条件下,Sialon-TiNC的添加量为6%时Al2O3-SiC-C质浇注料具有最优的综合性能。对优化Sialon-TiNC添加量的Al2O3-SiC-C质浇注料进行实际工况应用评价。工业试验结果表明：采用叶蜡石、金红石和焦炭合成的Sialon-TiNC复相粉体原料可以替代传统Al2O3-SiC-C质浇注料中30%的高成本刚玉、碳化硅以及氧化铝等微粉,达到了良好的使用效果。本研究工作为研发高性能出铁沟浇注料提供理论依据和新的技术路线,可以用改性廉价矿物原料替代高能耗的碳化硅和刚玉原料,降低铁沟料的成本,对缓解我国铝土矿等资源枯竭和节约能源具有重要的意义。更多还原

【Abstract】 In this work, aiming to meet the requirement for high-performance, low cost and the long-life refractory of blast furnace iron runner, Sialon-TiNC and Al2O3-SiC-TiNC composite powder were synthesized by using pyrophyllite, rutile and coke as raw materials during the carbothermal reduction and the carbothermal reduction and nitridation process. The influence of relevant technological conditions on phase was studied by thermodynamic analysis, XRD, SEM and EDS; the property of erosion resistance of Sialon-TiNC and Al2O3-SiC-TiNC composite materials was investigated and the high performance Al2O3-SiC-C iron runner castable adding Sialon-TiNC was prepared.The influence of different atmosphere (buried carbon conditions and flowing nitrogen atmosphere), different carbon content (the theoretical carbon content, exceeding 10%, exceeding 50% and exceeding 100%), different temperature range (1300～1600℃and 1400～1550℃) and the proportions of rutile on the phase composition and microstructure of the products was investigated. The results show that during the buried carbon condition the main phases in product with 10% rutile addition are corundum,β-SiC and TiN0.3C0.7 under 1600℃for 4 hours, whereas in flowing nitrogen atmosphere the main phases in product with 10% rutile addition areβ-Sialon and TiNi.7C0.3. The increasing in temperature and carbon content is beneficial for the forming ofβ-SiC andβ-Sialon. Besides, the existence of TiNC (TiN0.3C0.7 and TiN0.7C0.3) is contribute to improve the erosion resistance property of samples.The property of slag resistance of Al2O3-SiC-TiNC and Sialon-TiNC composite materials was studied. The results show that samples with different Ti content possessed high resistance to slag erosion due to the TiNC (TiN0.3C0.7 and TiN0.7C0.3) can enhance the resistance to slag erosion in samples. Particularly, samples with 10% rutile addition have the optimum performance of slag erosion resistance and oxidation resistance. The influence of Sialon-TiNC addition (0、3%,6%,9%,12%) on the physical properties at room temperature, oxidation resistance and resistance to slag erosion of Al2O3-SiC-C iron runner castable was investigated. The result shows that, the oxidation resistance and resistance to slag erosion of Al2O3-SiC-C iron runner castable containing different Sialon-TiNC addition are improved to some degrees. More specifically, the specimen with 6% Sialon-TiNC addition having optimum oxidation resistance, the thickness of oxide layer in samples treated under 1450℃is 2.77mm, while the thickness of oxide layer in sample without adding Sialon-TiNC is 5.16mm. Besides, Sialon-TiNC could prevent slag erosion and penetration to the iron runner castable. And the specimen with 6% Sialon-TiNC addition have optimum low temperature (110℃×24h) and high temperature modulous of rupture which are 7.75MPa and 7.35MPa, and cold crushing strength which are 29.53MPa and 31.83MPa, respectively. The permanent linear change of specimen treated under 1450℃is just 0.01%, and the apparent porosity is 13.86%, bulk density is 2.84g/cm3. Under the condition of experiment, Al2O3-SiC-C castable with 6% Sialon-TiNC addition possesses optimum comprehensive performance.Industrial application of Al2O3-SiC-C castable added Sialon-TiNC with optimize amount was evaluated. The result shows that Sialon-TiNC composite powder materials, obtained from easily available pyrophyllite, rutile and coke, can substitute 30wt% micropowder of the high-cost corundum, SiC and alumina in traditional Al2O3-SiC-C castable, which achieving good application effect. Because the high energy consumption corundum and SiC can be replaced by the modified cheap mineral materials, the cost for producing castable could be reduced, which means this work can provide scientific basis and a technical route for the research and development of high performance iron runner castable, and play a pivotal role in relief the bauxite resources shortage and energy conservation.更多还原