高炉非金属冷却壁用Al_2O_3-SiC-C质浇注料的研制

为了提高高炉非金属冷却壁用Al2O3-SiC质浇注料的抗渣性,在其中引入人造石墨,研制了高炉非金属冷却壁用Al2O3-SiC-C质浇注料,着重研究了六偏磷酸钠(SHP)、聚丙烯酸钠(PAANa)、萘系减水剂(NTD)和SkipLiquid型减水剂(SL)4种分散剂及其加入量对这种含碳浇注料流动性、耐压强度、体积密度和显气孔率的影响以及碳(人造石墨)的添加量对浇注料试样的耐压强度、体积密度、显气孔率和抗渣性能的影响。结果表明:1)分散剂SL的效果最好,其最优外加量为0.2%;2)人造石墨添加量为5%时,浇注料试样的抗渣性能和烧后耐压强度达到最优,综合性能最佳。     

蜡石粒度组成对铁水包用ASC材料性能的影响

在铁水包用常规Al2O3-SiC-C砖的配料组成中引入不同粒度组成的蜡石,研究了蜡石粒度组成对Al2O3-SiC-C材料加热永久线变化率、显气孔率、体积密度、耐压强度、抗氧化性和抗渣性的影响。结果表明:随着处理温度的升高,各试样的显气孔率先增大后减小,体积密度减小;随着所添加蜡石粒度的减小,试样在1 000和1 400℃埋炭热处理后的永久线变化率减小,常温耐压强度增大,1 400℃时的抗氧化性增强,但1 500℃时的抗侵蚀性降低。     

Comparisons Between Vibration and Self-Flowing Ultra-Low Cement Castables Properties in Al2O3-SiC-C System

In this study, the properties of self-flowing ultra-low cement castables in Al2O3-SiC-C system have been investigated and compared to vibration castables. The major physical and mechanical properties, microstructure and corrosion behavior of these castables against slag have been evaluated. The results showed that the microstructure of Al2O3-SiC-C self-flowing castable is more uniform than the vibrated structure. Also self-flowing castable has smaller pore size and more uniform pore size distribution. Hence, density, strength, oxidation and slag resistance of the self-flowing castables is higher than that of vibration castables. Therefore, besides other benefits such as noise free, easy installation, fewer mold defects and reduced installation costs, Al2O3-SiC-C self flowing ultra low cement castables will have longer service life in comparison with vibration casables.     

Al_2O_3－SiC－C质浇注料抗热震性和抗渣铁侵蚀性的研究

对新研制的Ａｌ２Ｏ３－ＳｉＣ－Ｃ质浇注料和现用出铁沟料的抗热震性和抗渣铁侵蚀性进行了研究、结果表明，该材料具有较高的抗渣铁侵蚀能力和较好的抗热震稳定性。调节Ｓｉ与Ｃ的比例可生成高强度、耐渣蚀的纤维状ＳｉＣ。     

Effect of Al Addition on Properties of Al_2O_3-SiC-C Dry Ramming Mixes for BF Trough

Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition...     

Si3N4-Fe对Al2O3-SiC-C质铁沟浇注料性能的影响

利用Si3N4的优良性质及金属塑性相Fe的作用,将其添加到高炉出铁沟用Al2O3-SiC-C浇注料中,以改善材料的力学性能和抗氧化性能.对高温处理后试样强度、显气孔率测试以及对氧化层的SEM分析,结果表明,添加适量的Si3N4-Fe,材料的显气孔率降低,强度提高,抗氧化性增强.     

h-BN加入量对低水泥刚玉质浇注料性能的影响

为了提高低水泥刚玉质浇注料中温处理后的强度和抗热震性,在其配料中引入不同量的h-BN粉(其质量分数分别为0、0.5%、1%、1.5%和2%),经成型、养护、脱模、烘干、750℃热处理后,检测试样的体积密度、显气孔率、常温抗折强度、常温耐压强度、抗热震性,并进行XRD分析。结果表明:随着h-BN加入量的增加,750℃处理后试样的显气孔率有所减小,体积密度逐渐减小,常温耐压强度逐渐增大,常温抗折强度也呈增大趋势,抗热震性逐渐改善。可见,加入h-BN有助于提高低水泥刚玉质浇注料中温处理后强度和抗热震性。     

原位生成非氧化物对刚玉基浇注料性能的影响

为了进一步提高刚玉基浇注料的高温使用性能,在超低水泥刚玉浇注料中加入质量分数分别为0、4%、6%、8%、10%的硅粉,经振动浇注成型、养护、烘干后,在氮气气氛中于1 450℃氮化处理40 h,测定试样的加热永久线变化及烧后试样的显气孔率、体积密度、常温抗折强度和不同温度(分别为1 000、1 200、1 300和1 400℃)下的热态抗折强度,并对部分氮化后试样进行XRD和SEM分析。结果表明:1)随着硅粉加入量的增加,试样在氮化处理过程中从发生微收缩到发生微膨胀,显气孔率略有增大,体积密度和常温抗折强度下降,热态抗折强度显著提高;2)氮化处理后,试样中原位生成了非氧化物β-SiAlON、O’-SiAlON和α-Si3N4等。     

碳的种类对铝锆碳滑板性能的影响

分别对单独加入4%(质量分数)鳞片石墨、炭黑、沥青碳3种碳材料和加入不同碳材料(总质量分数4%)复合的铝锆碳滑板进行了树脂加入量、耐压强度、高温抗折强度、显气孔率、体积密度等物理性能以及抗氧化、抗热震性能比较。试验结果表明添加石墨可以实现低的树脂加入量,试样的显气孔率低,抗氧化性好;添加炭黑可以提高试样的强度;添加沥青碳,则可提高试样的抗热震性,但抗氧化变差;复合添加这3种碳材料,可以得到强度高、抗热震好的铝锆碳滑板试样。     

硅线石对矾土基浇注料性能的影响

以矾土为主要原料,加入硅线石粉、SiO2微粉、活性A l2O3微粉、水泥等制备矾土基浇注料,研究了硅线石加入量(质量分数分别为0、4%、8%和12%)对浇注料常温性能和抗渣侵蚀性能的影响。结果表明:随着硅线石加入量的增加,浇注料的常温强度和体积密度下降,显气孔率增大;在浇注料中加入硅线石有助于提高试样的抗渣侵蚀性能,但加入质量分数大于8%时,试样抗渣侵蚀性能下降,渣渗透深度和侵蚀深度增加;硅线石加入质量分数为4%~8%时,浇注料的综合性能较好。     

Substitution of antioxidant Si by andalusite fine powder in Al2O3-SiC-C castables

Our previous research showed that the addition of andalusite aggregates can enhance the oxidation resistance of Al₂O₃-SiC-C castables; this is attributed to the transformation of andalusite into a silica-rich glass phase that blocks pores. Theoretically, andalusite with a smaller particle size would achieve a higher extent of conversion and generate more silica-rich glass, which would be more conducive to blocking pores. Therefore, this study evaluates the influence of andalusite fine powder on the oxidation resistance of Al₂O₃-SiC-C castables containing a reduced amount of Si antioxidant. The results show that introducing a small amount of andalusite fine powder endows the Al₂O₃-SiC-C castables with significant oxidation resistance so that the traditional addition of Si metal as an antioxidant can be substantially reduced or even completely eliminated. Meanwhile, the thermal shock stability and strength of the castables were also enhanced.     

复合抗氧化剂对Al2O3-SiC-C砖性能的影响

以均化矾土、板状刚玉、碳化硅、石墨为主要原料,利用酚醛树脂作为结合剂,研究了复合抗氧化剂(硅粉、铝粉、碳化硼)的引入形式及加入量对Al2O3-SiC-C砖的性能影响.结果表明:添加复合抗氧化剂可提高Al2O3-SiC-C砖的高温抗折强度,随铝含量的增加,对提高高温抗折强度的提高越明显;抗氧化效果从强到弱依次为:添加碳化硼的复合抗氧化剂>复合铝硅抗氧化剂>金属铝>金属硅;在复合抗氧化剂中引入碳化硼能够有效的提高Al2O3-SiC-C砖的抗渣侵蚀性能及热震稳定性.     

原位生成SiAlON增强Al2O3-SiC-C铁沟浇注料的力学性能

根据热力学计算,在还原气氛下,通过引入Si3N4和提高Si的加入量等途径原位合成制备出SiAlON增强Al2O3-SiC-C浇注料是完全可行的.实验研究了Si3N4的加入量和Si的加入量对Al2O3SiC-C铁沟浇注料力学性能的影响.结果发现随着Si3N4加入量的提高,材料的力学性能先增大,后减小,加入量为6%时材料力学性能最佳;Si的加入量对材料性能的影响较为显著,材料的力学性能随着其加入量的增多而逐渐提高,其最佳加入量为5%.XRD及SEM分析结果表明,SiAlON增强Al2O3-SiC-C铁沟浇注料性能优良的根本原因是由于Si3N4、Si与Al2O3原位反应生成的SiAlON改变了材料基质结合形式,提高了基质的固-固直接结合率.     

Effect of SiC–graphite–Al-metal addition on low- and ultra-low cement bauxite castables

Eight batches of low- and ultra-low cement castables were prepared from calcined Chinese bauxite and high alumina cement (HAC). The effect of alumina-cement replacement by SiC, graphite and aluminum metal on the sinterability and properties of these castables was investigated. Physical properties such as bulk density and apparent porosity of hydrated and sintered castables were studied. The sintered castables were also characterized for their solid phase compositions and microstructure using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. In the castables containing SiC, new phases such as mullite (3Al₂O₃·2SiO₂), SiC, and quartz (SiO₂) were formed at the expense of calcium aluminate phases (i.e. CA and CA₂; the main cement phases). Generally, the bulk density of the control castable sample was the highest among all prepared samples, while the batches containing graphite showed the lowest bulk density. The presence of Al-metal reduced the oxidation of SiC and consequently increased the densification of the castables compared with castables containing graphite only. Cold crushing strength (CCS) of the hydrated specimens i.e. green castables, decreased as the additives contents increased at the expense of HAC which is responsible for the bonding at room temperature. The highest CCS value of the sintered castable was obtained for the sample containing 6 wt.% SiC, 3 wt.% CA and 0.5 wt.% Al-metal.     

Effect of Ti （C,N） on Properties of Low-carbon MgO- C Bricks

The effect of Ti （ C, N） on properties of low-carbon MgO - C bricks was investigated. The phase composition and the microstructure of the matrix of low-carbon MgO - C brick containing Ti （ C, N） were studied by XRD and SEM analysis together with EDS. The results showed that Ti （ C, N） distributed in the matrix of lowcarbon MgO - C brick uniformly after being treated at 1 600 ~C for 3 h in coke powder bed, and Ti （C, N） and MgO formed a solid solution. After the treatment at 1 600 ℃ for 3 h in coke powder bed, the bulk density and cold crushing strength of low-carbon MgO - C brick with Ti （ C, N） decreased, and the apparent porosity and linear change rate of specimens increased. The oxidation resistance of low-carbon MgO - C brick with Ti（ C, N） was superior to that of low-carbon MgO - C brick with no additives, but inferior to that of low-car- bon MgO - C brick with Al powder. The slag resistance of the specimen with Ti （ C, N） was excellent as well.     

骨料浸渍硅溶胶对矾土基耐火材料性能的影响

为了改善矾土基耐火材料的力学性能和抗热震性能,分别以SiO2含量(w)为15%和30%的硅溶胶对3~1 mm的矾土熟料粗颗粒进行浸渍处理,再与≤1 mm的矾土熟料颗粒、≤0.074 mm的矾土熟料细粉、α-Al2O3微粉、≤0.074 mm的红柱石细粉、≤0.074 mm的广西白泥、纸浆废液等经配料、成型、干燥、烧成(1400、1450和1500℃保温3 h),制得矾土基耐火材料,同时制备了使用未浸渍3~1 mm矾土熟料的空白试样。结果表明:1)随着烧成温度的升高,试样的常温抗折强度和常温耐压强度呈先升高后降低的变化趋势,其最佳烧成温度为1450℃。2)随着浸渍用硅溶胶浓度的提高,试样的烧后线变化增大,体积密度、常温抗折强度和常温耐压强度降低,高温抗折强度、荷重软化温度和抗热震性能提高,这是由骨料表面硅溶胶层中的SiO2与骨料及周围基质中的Al2O3反应生成了莫来石所致。3)当浸渍用硅溶胶中SiO2含量(w)为15%时,材料的综合性能最优。     

氧化铝微粉加入量对低碳镁碳砖性能的影响

以电熔镁砂、石墨、金属Al和氧化铝微粉为主要原料,热塑性酚醛树脂为结合剂,制备了w(C)5%的低碳镁碳砖试样,研究了氧化铝微粉加入量(其质量分数分别为0、3%、5%、7%、9%)对低碳镁碳砖的常温物理性能、抗热震性和抗氧化性的影响。结果表明:(1)随着氧化铝微粉加入量的增加,低碳镁碳砖试样的体积密度、常温强度和高温强度均先升高后降低,显气孔率则先降低后升高;抗热震性和抗氧化性随微粉加入量的增加呈先改善后变差的趋势;其中,微粉加入量为5%的低碳镁碳试样综合性能最好。(2)低碳镁碳砖试样性能的改善主要是由于加入的氧化铝微粉和MgO在高温下原位反应生成连续分布的尖晶石,增强了基质的陶瓷结合;但氧化铝微粉加入量过大时,由于大量原位反应引起材料产生过大的体积膨胀,会导致基质结构疏松,从而恶化镁碳砖的性能。     

Si粉氮化法合成Si3N4-SiC材料

以SiC、Si粉和Al2O3微粉为主要原料,羧甲基纤维素(CMC)为临时结合剂,采用氮化反应烧结法合成了Si3N4-SiC材料,主要研究了Si粉的粒度(≤0.074、≤0.044 mm)和加入量(质量分数分别为15%、17%、19%、21%)、烧成温度(分别为1 380、1 400、1 420、1 430、1 440、1 460和1 480℃)、Al2O3微粉添加量(质量分数分别为0、1%、2%、3%、4%,取代相应量的SiC粉)对Si3N4-SiC材料的显气孔率、体积密度、常温耐压强度、常温抗折强度、高温抗折强度及Si3N4含量的影响。结果表明:1)采用粒度较细Si粉的试样具有较高的致密度、常温强度、高温抗折强度和Si3N4含量;随着Si粉加入量的增加,试样的致密度略有增大但变化不大,常温强度和Si3N4含量逐渐增大,而高温抗折强度先增大后减小;2)适当提高烧成温度会明显改善Si3N4-SiC材料的高温抗折强度,但当温度超过1 440℃反而略有下降;3)添加Al2O3微粉对烧后试样的致密度、常温强度和高温抗折强度有益。综合来看,Si粉的适宜添加量(质量分数)为17%,较适宜的烧成温度为1 420～1 440℃,Al2O3微粉的适宜添加质量分数为2%。     

酚醛树脂加入量对钢包渣线再生镁碳砖性能的影响

利用钢包渣线用后镁碳砖再生料制备了钢包渣线再生镁碳砖,在再生料加入质量分数为80%的基础上,研究了酚醛树脂5323加入量(质量分数分别为3.25%、3.5%、3.75%、4.0%、4.25%)对再生镁碳砖致密度、强度和抗氧化性的影响。结果表明:1)随着酚醛树脂加入量的增加,200℃热处理后再生镁碳砖的致密度、常温耐压强度、常温抗折强度及高温抗折强度均增大,抗氧化性增强;2)随着酚醛树脂加入量的增加,900℃埋炭处理后试样的致密度增大,但当酚醛树脂加入量(w)达到4%后其致密度变化不大;3)再生镁碳砖中酚醛树脂加入量(w)以3.5%～4%为宜。     

AlN对Al2O3-C材料性能的影响

采用碳热还原法制备的AlN复合粉(主成分是AlN和Al2O3)部分取代Al2O3-C材料中的Al2O3微粉,研究了AlN复合粉加入量(分别为0、15%和25%)对Al2O3-C材料性能的影响。结果表明:(1)试样的显气孔率随AlN复合粉取代量的增加而增大,体积密度、常温抗折强度随AlN复合粉取代量的增加而减小;(2)AlN复合粉的引入能显著提高Al2O3-C材料的高温抗折强度;(3)添加AlN复合粉的试样经熔钢侵蚀后,在材料表面形成较连续的致密层,有利于提高材料的抗熔钢侵蚀性和冲刷性。