【作者】 李慈颖；

【导师】 李亚伟； 高运明；

【作者基本信息】 武汉科技大学 ， 材料学， 2007， 硕士

【摘要】 本文在全面总结回顾国内外含钛高炉渣,特别是攀钢含钛高炉渣的综合利用现状的基础上,提出综合利用攀钢含钛高炉渣的一种方案,即将含钛高炉渣进行碳氮化处理以提取Ti（C,N）作耐火材料,而残渣用于生产水泥或直接铺路等,或将含钛高炉渣直接应用在耐火材料中,以达到全量和高附加值利用的目的。具体研究内容包括:一热力学分析表明,渣中钛的氧化物碳氮化比碳化更容易,在1200℃左右就可以与C、N2反应生成TiN,而在1300℃左右才可碳化生成TiC。本论文碳（氮）化实验研究温度范围为1300～1500℃。二在热力学分析的基础上,首先以TiO₂-CaO-SiO₂-Al₂O₃-MgO五元合成渣为主要原料,分别在氩气或氮气气氛下进行了碳化或碳氮化还原实验,并采用X-射线衍射仪和扫描电镜研究了产物的相组成和显微结构,结果表明在氩气气氛下,产物主要为TiC;在氮气气氛下,产物主要是以TiN为主的Ti（C,N）;氩气气氛下TiC的粒度比同一实验条件氮气气氛下Ti（C,N）的粒度要小1～4μm。三以攀钢含钛高炉渣为原料,在氮气气氛下进行碳氮化实验,考察碳氮化处理温度、保温时间及配碳量对Ti（C,N）的形成及其晶粒大小的影响。结果是较理想的碳氮化工艺条件为:碳氮化处理温度1450℃、保温时间2h、配碳比为1。此时,碳氮化比较完全,Ti（C,N）的平均粒径可达2μm以上。在此基础上,讨论了添加剂（如K₂CO₃、CaF₂和Fe₂O₃）的作用,结果表明,渣中加入适量的添加剂对Ti（C,N）的生成量影响不大,但可有效地促进其晶粒的生长及团聚,其中最大Ti（C,N）团聚体尺寸可达23μm左右,加入Fe₂O₃的试样中Ti（C,N）晶粒及团聚体最大,不加任何添加剂的试样中Ti（C,N）晶粒最小,且没有聚集长大的趋势。四初步研究了攀钢含钛高炉渣或经（1300℃,3h）碳氮化处理后的攀钢含钛高炉渣对铁沟捣打料性能的影响,并探讨了其在1450℃下保温3h后的抗渣性能。结果表明攀钢含钛高炉渣或经处理后的攀钢含钛高炉渣均能有效地改善铁沟捣打料的各项常规物理性能及抗渣性。更多还原

【Abstract】 The situation for utilizing of titanium-bearing blast furnace slag comprehensively in Panzhihua Iron and Steel Company is systematically reviewed, then the carbonitridation of titanium-bearing slag is brought up to produce Ti(C, N) for refractories. Moreover, the residual slag can be used for cement, pavement, etc. after Ti(C, N) is separated from carbonitrized slags. So it may be an innovative approach for the comprehensive utilization of titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company. The research work is summarized as follows: First, the thermodynamic analysis shows that reaction between titanates in slag, C and N2 occurs to produce TiN at 1200℃and TiC at 1300℃. The temperature range of 1300～1500℃is selected to treat the slag.Second, based on thermodynamic analysis, carbothermal reduction process was carried out in argon and nitrogen atmosphere for the pre-molten slag of TiO2-CaO-SiO2-Al2O3-MgO system according to titanium-bearing blast furnace slags in Panzhihua Iron and Steel Company. The phase evolution and microstructure of the products were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the final products mainly consist of TiC in argon atmosphere and Ti(C, N) (mainly TiN) in nitrogen atmosphere. The grain size of TiC in argon atmosphere are less about 1～4μm than that of Ti(C, N) in nitrogen atmosphere in the same of experiment condition.Third, carbothermal reduction experiment was carried out for titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company in nitrogen atmosphere at high temperature. The effects of nitriding temperature, isothermal treatment time and carbon content on formation and grain size of Ti(C, N) were studied by XRD, SEM and electron probe micro-analysis (EPMA). The results showed the better technical conditions are that nitriding temperature is 1450℃, isothermal treatment time is 2 hours, and carbon ratio is 1. The average grain size of Ti(C, N) is about 2μm in this experiment condition. Based on the above, the effect of additives such as K2CO3, CaF2 and Fe2O3 on the formation and grain growth of Ti(C, N) was studied. The results show that all the additives could modify the liquid slag properties and promote effectively the grain growth of Ti(C, N). Among them, Fe2O3 is the most effective additive and the agglomerate of Ti(C, N) grain grew up as its amount increased. Its maximum size reached up to 23μm. Meanwhile, the minimum grain size was found in the samples where no additive was added.Fourth, the effects of titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company on the physical properties of ramming refractory and its slag resistance at 1450℃for 3 hours were investigated in blast furnace trough. The results showed titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company could improve the physical properties of ramming refractories in blast furnace trough and slag resistance effectively.更多还原