Influences of ZrO_2-SiC Composite Powder and Commercial SiC on Properties of Al_2O_3-C Refractories

In order to improve oxidation resistance and thermal shock resistance of Al2O3-C refractories, two groups of specimens were prepared with phenolic resin as binder, adding 0, 2 wt%, 4 wt% and 6 wt% commercial SiC or ZrO2-SiC composite powder synthesized from zircon respectively to Al2O3-C refractories, pressing at 200 MPa, drying fully at 250 ℃, and then carbon embedded firing at 1 400 ℃ for 2 h. Oxidation resistance and thermal shock resistance were researched, phase composition was analyzed by XRD. The res...     

Effect of Nano Carbon Black and Graphite Flake on Properties of Low Carbon Al_2O_3-C Refractories

Low carbon Al_2O_3-C refractories specimens were prepared with tabular alumina( 3. 0- 1. 0,1. 0- 0. 5,0. 6- 0. 2,≤0. 3,≤0. 045 and ≤0. 02 mm),active alumina micropowder( ≤2 μm) and silicon( ≤0. 045mm) as main raw materials. Nano carbon black( N220) and natural graphite flake( ≤0. 074 mm)were adopted as the carbon sources. The specimens were treated at 800,1 000,1 200 and 1 400 ℃ under coke embedded atmosphere. The effects of additions of nano carbon black and graphite flake on mechanical properties and thermal shock resistance of the specimens were studied. Their mechanical properties were measured by threepoint bending test and thermal shock resistance was determined by water quenching method. The phase composition of the specimens was analyzed with X-ray diffraction and microstructures were observed through FESEM.The results reveal that:(1) the strengths of Al_2O_3-C refractories with these two carbon sources show no big differences when coked at lower than 1 000 ℃; when coked at over 1 200 ℃,the strengths of the specimens with graphite added are much higher than those of the specimens containing carbon black due to much more silicon carbide whiskers formed;( 2) since the nano carbon black has small particle size,they can be filled into interstice of Al_2O_3 particles to form the nano carbon network structure,absorbing and relieving the thermal stressgenerated from expansion and contraction and reducing the thermal expansion coefficient of the specimens,thus their thermal shock resistance is better than that of the specimens containing graphite;( 3) low carbon Al_2O_3-C refractories with good mechanical properties and excellent thermal shock resistance can be prepared with combination of nano carbon black and graphite flake.     

Recent Progress of Carbon Nanotubes Reinforced MgO-C and Al_2O_3-C Refractories

Carbon nanotubes （CNTs） have been extensively studied over the last two decades since they possess excellent properties.CNTs have been considered as new promising reinforcements for carbon containing refractories （CCRs）.Current research progress of the CNT-reinforced MgO-C and Al2O3-C refractories was summarized in this mini-review,and the CNT-reinforced CCRs possess remarkable mechanical properties and superior thermal shock resistance compared to CCRs without CNTs.     

硅粉对金属Al结合镁铝碳滑板材料性能的影响

金属Al结合镁铝碳质滑板抗侵蚀性优良,适用于浇铸钙处理钢.研究了加入硅粉对镁铝碳材料常规物理性能、抗氧化性、抗渣性的影响.结果表明,加入硅粉后,材料800℃ 和1000℃ 的烧后抗折强度(MOR)和高温抗折强度(HMOR)提高,但是加入过多硅粉会使材料1000～1600℃ 的烧后显气孔率升高,强度降低.加入适量的硅粉可以改善材料抗氧化性和抗侵蚀性.     

Effect of ZrO_2-nitrides Composite Powder Addition on Oxidation Resistance of Al_2O_3-C Refractories

Oxidation of carbon is the main problem of Al2O3-C refractories.ZrO2-nitrides composite powder was synthesized through carbothermal reduction and nitridation (CRN) of zircon.The effect of ZrO2-nitrides composite powder addition on oxidation resistance of the Al2O3-C refractories was investigated by measuring the thickness of oxidation layer.Phase compositions of the Al2O3-C refractories before and after oxidation were investigated by X-ray diffraction (XRD).Results show that the oxidation resistance of the ...     

强碱分离EDTA络合滴定法测定铝锆炭质耐火材料中三氧化二铝

试验证明，强碱分离ＥＤＴＡ络合滴定法测定铝锆炭质耐火材料中Ａｌ２Ｏ３时的分离碱度为５％（过加１０ｍｌＮａＯＨ溶液），在沸水浴中保温５～１０ｍｉｎ；ＥＤＴＡ络合条件为：煮沸３～５ｍｉｎ，在２０～７０℃下滴定，六次甲基四胺缓冲溶液（ｐＨ＝５．５）加入量为１５ｍｌ．分析结果准确可靠。     

铝炭制品防氧化涂料的作用机理

采用热分析等研究方法，分析了铝炭制品的氧化过程，研究了以阻断铝炭制品与氧气接触来实现防氧化的硼硅酸盐系涂料的高温特性和防氧化机理，以及不同结合剂对涂料与铝炭制品界面行为的影响。     

高炉用Al_2O_3－C砖的研制

本工作研究了高炉用Ａｌ２Ｏ３－Ｃ砖的化学组成、烧成温度对试样性能的影响，并借助光学显微镜和扫描电镜对减侵蚀后的Ａｌ２Ｏ３－Ｃ和高铝试样进行了分析，讨论了Ａｌ２Ｏ３－Ｃ砖抗碱性优于高铝砖的原因。     

金属结合不烧铝碳滑板的中温力学性能研究

模拟不烧铝碳滑板配方,以板状刚玉、金属铝粉、鳞片石墨为主要原料,热固性酚醛树脂为结合剂,经混练、成型、烘干、切割、磨制成规格为25 mm×25 mm×130 mm的试样,检测了200 ℃×24 h烘干、500～1100 ℃×3 h埋碳热处理后试样的高温抗折强度和应力-应变关系.借助XRD、SEM和EDS对试样进行物相组成和显微结构分析,以期对高性能滑板的开发、研制和改进提供理论依据和参考.实验结果表明: 金属铝粉的熔化(熔点660 ℃)导致金属铝结合不烧铝碳滑板的高温抗折强度和弹性模量在700 ℃左右出现最低值;之后随温度的升高,金属铝发生反应生成六方状氧化铝和纤维状碳化铝,滑板的显微结构和物相组成发生明显变化,高温抗折强度和弹性模量急剧增大,1100 ℃时达到所测试温度范围内的最大值,并有继续增大的趋势.     

铝炭－锆炭复合浸入式水口的生产和使用

对Ａｌ２Ｏ３－Ｃ／ＺｒＯ２－Ｃ复合式注入水口原料选择、添加剂及结合剂作用与选择、ＺｒＯ２的稳定剂和加入量的确定、生产过程的工艺特点和使用要求进行了研究。     

含钒渣对铝碳材料的侵蚀

为了探讨含矾渣对铝碳材料的侵蚀机制,用动态感应抗渣法研究了w(V2O5)=10%、碱度2.8,w(V2O5)=6%、碱度2.8,w(V2O5)=6%、碱度1.44的3种含钒渣对铝碳材料的侵蚀。结果表明:随着V2O5含量(w)由6%增加到10%,铝碳材料的熔损指数增加;随着碱度的增加,铝碳材料的熔损指数也增加;添加电熔镁砂有助于提高铝碳材料的抗侵蚀性能。显微分析表明:V、Ti元素渗透能力强,渗透深,而尖晶石可固溶少量V2O5、MnO及FeO。     

高温抗氧化涂料的研究

介绍了一种新型耐火材料抗氧化涂料。此涂料由复合氧化物、氧化硅、氧化铝及施工性能调节剂充分反应制成。结果表明,在1 500℃内,涂料对Al2O3-ZrO2-C耐火材料具有良好的保护效果。     

添加剂TiO2和Cr2O3对复合陶瓷Mullite／ZrO2／Al2O3的影响

利用添加剂改善结构陶瓷材料的性能是一种较佳的方法,复合陶瓷mullite/ZrO_2/Al_2O_3具有较高的力学性能。试验证明:加入不同的添加剂对复合陶瓷有不同的影响,TiO_2会使材料的力学性能大幅度降低;Cr_2O_3会使材料的硬度显著提高。     

镁铝炭砖和铝镁炭砖在连铸包衬上的应用

用镁铝炭砖和铝镁炭砖综合砌筑连铸包衬，使用寿命由５３次（高铝砖衬）提高到１０１次，耐火材料单耗由４．３８ｋｇ／ｔ钢降低到２．３ｋｇ／ｔ钢。     

Influence of Nano-Al_2O_3 on Properties of Magnesia Chrome Refractories

Magnesia chrome bricks were prepared with fused MgO-Cr2O3 synthesized material,fused magnesite and chrome ore as main starting materials. Nano-Al2O3 was added into refractories ( 2% ,4% and 6% in mass) substituting for Al2O3 micropowder. After mixing and shaping,the bricks were fired at 1 550 ℃ ,1 600 ℃ , 1 650 ℃ and 1 750 ℃ ,respectively. The microstruc-ture,sintering property,mechanical properties,thermal shock resistance and slag resistance of the specimens with the addition of nano-Al2O3 were investigated. The re-sults indicate that the performance of brick with 4 mass% of nano-Al2O3 is greatly improved after firing at 1 650 ℃ .     

通过改善材质提高滑板寿命

日本住友金属工业公司鹿岛厂第一炼钢车间在对连铸机改造的同时，对钢包用滑板进行了改进。滑板采用小孔径，3块板改为2块板，并改进材质，同传统材料相比，滑板寿命提高了33％，成本降低了61％。     

Al2O3–TiC基复相陶瓷的制备和性能

Al2O3-TiC基复相陶瓷具有高强度、高硬度和较好的高温稳定性, 常用于刀具、发热体和电子器件. 本文综述了Al2O3-TiC基复相陶瓷的各种制备方法及其优缺点、常温和高温性能、各种增韧手段和增韧机制, 并展望了Al2O3-TiC基复相陶瓷研究的发展方向.     

Al2O3多孔陶瓷的制备和性能研究

采用乙基纤维素为成孔剂制备了Al2O3多孔陶瓷,探讨了工艺参数对其性能的影响。研究结果表明,造孔剂含量、球磨时间及烧结温度均对多孔陶瓷的气孔率和抗折强度有影响。烧结温度的升高使得气孔率降低,但变化不明显,抗折强度明显提高。随造孔剂含量的升高,使得气孔率逐渐上升,超过20％后变化趋于平稳。随着球磨时间的增加,试样呈现气孔率下降和抗折强度升高的趋势。以烧结温度为1580℃,造孔剂含量20％;球磨时间为2．5h的条件下,可获得高显气孔率、抗折强度较高的舢203多孔陶瓷。     

ZrB_2对Al-Si复合Al_2O_3-C材料高温力学性能的影响

以板状刚玉、α-Al2O3微粉、Al粉、Si粉、ZrB2和石墨为原料,酚醛树脂为结合剂,采用150 MPa压力压制成25 mm×25 mm×145 mm的试样。研究ZrB2加入量(其质量分数分别为0.5%、1%、1.5%、2%)对Al-Si复合Al2O3-C材料高温抗折强度和抗热震性的影响,并分析了试样物相组成和显微结构的变化。结果表明:(1)加入ZrB2质量分数≥1%时,可明显提高200℃烘烤和700℃热处理后试样的高温抗折强度和抗热震性;加入ZrB2对1 500℃烧后试样的高温抗折强度和抗热震性影响不大。(2)加入ZrB2后AlN和SiC生成量明显增加,晶体发育良好,形成连续交叉连锁的网络结构,对材料增强、增韧作用显著,有利于提高材料的高温强度和抗热震性。     

Development and Application of Al_2O_3-Si_3N_4 Refractories Used in Blast Furnace

Newly developed Al2O3-Si3N4 composite refractories used for blast furnace is introduced in this work. Al2O3-Si3N4 composite refractories attacked by alkali vapor and blast furnace slag was investigated. High performance Al2O3-Si3N4 composite refractories was produced and used at both 2560m^3 blast furnaces of Tan-gsteel and No. 5 blast furnace of Shaosteel.