钢包内衬用不烧铝镁砖的开发

过去广泛采用高铝砖及含碳砖作钢包内衬。高铝砖的缺点是抗侵蚀性差,而含碳砖的抗侵蚀性好,但会导致钢水中的碳含量增大。针对存在的问题,开发了Al2O3-MgO浇注料和Al2O3-MgO砖,用于筑造钢包内衬,得到一定效果。     

Insulating Permanent Lining of Calcium Hexaluminate Based Castable for 300t Ladle in Baosteel

Minimizing of heat loss of liquid steel through the ladle lining led to the integration of increasing insulation function of the permanent lining and high-quality insulating layer between the permanent lining and the ladle steel shell.In this paper,a study was made on physical and thermomechanical properties and corrosion resistance of calcium hexaluminate based castables.The chemical and physical properties of CA6 based castables fabricated in this work can fulfill general requirements of the permanent lining in ladle.The permanent linings of CA6 based castables offer superb thermal insulation and corrosion resistance,compared to conventional refractory systems of 300t ladle in Baosteel.Both functions of insulation and safety work effectively in whole process of ladle operation.     

Effects of Dispersive Agent and Alumina Micropowder on Workability of Al_2O_3-MgO Castables for Steel Ladles

This work aims at enhancing the workability of Al2 O3-Mg O castables. Al2 O3-Mg O castables were prepared using tabular alumina particles( 5-3,3-1,≤1 mm),tabular alumina fines( ≤0. 088 mm),fused magnesia( ≤1 mm),reactive alumina micropowder( PFR40,PBR,and CL) and calcined alumina micropowder( AC34 B5 and CT) as the main starting materials,calcium aluminate cement( Secar71) as the binder,and polycarboxylic acid water reducer WS,FS,and AD as the dispersive agent,respectively. Effects of three dispersive agents addition( 0. 4 mass% WS,0. 2 mass% FS and 1 mass% AD),two kinds of reactive alumina micropowder addition( PFR40 and PBR),composite alumina micropowder addition( PFR40-AC34 B5 and CL-CT,the mass ratio from 9/0 to 3/6)on the flow value,apparent porosity,bulk density,cold crushing strength and cold modulus of rupture of Al2 O3-MgO castables were investigated. The results show that:( 1) with PBR or PFR40,the castables with0. 4 mass% WS own better performance than those with0. 2 mass% FS or 1 mass% AD;( 2) compared with the castables with CL-CT composite powder, the castables with PFR40-AC34 B5 composite powder have slightly higher flow value; with the decreasing ratio of PFR40 and AC34 B5,or the decreasing ratio of CL andCT,the castables have declined flow value and the dried castable specimens have decreased density but the mildly changed strength; in consideration of the high price of reactive alumina,a proper compositing ratio shall be selected.     

MgO含量对铝镁质浇注料性能的影响

借助ＳＥＭ和ＥＤＡＸ分析等手段研究了ＭｇＯ含量对铝镁质脱硅出铁沟浇注料性能的影响。结果表明：ＭｇＯ含量（质量分数,下同）提高至３％,能显著地提高浇注料对脱硅剂的抗渗透性能,这主要是由于浇注料中反应生成的 ＭｇＡｌ２Ｏ３能大量吸收脱硅剂中的ＦｅＯ（Ｆｅ２Ｏ３）,形成尖晶石固溶体,引起熔渣粘度增大;但生成的ＭｇＡｌ２Ｏ３量过多时,会引起浇注料的组织结构疏松,降低浇注料的抗渣性能。浇注料中适宜的ＭｇＯ含量为３％－６％。     

对提高钢包寿命的MgO-C砖制造技术和炉衬设计的研究

论述了钢包用MgO-C砖技术的开发和各种不同原料及结合剂、外加剂的使用。对钢包各个区域的内衬设计进行了研究,并进行了三个阶段的试验。指出改进后的MgO-C砖显著提高了Rourkela钢厂钢包的使用寿命。     

浇注成型铝镁质座砖及上水口的研制与使用

以电熔刚玉砂、刚玉细粉、Al2O3微粉、轻烧镁粉、电熔镁砂粉及纯铅酸钙水泥为原料生产铝镁质浇注料。制品的高温抗折强度27．41MPa。制成的座砖及上水口在安钢和重钢钢包上应用,寿命可与包衬同步。     

Preparation of Microporous Corundum and Its Effect on Properties of Al_2O_3-MgO Castables

Based on the pore size design of microporous aggregate by numerical simulation applying porous media model,α-Al2O3 micropowder,industrial Al2 O3fine powder,α-Al2O3 micropowder ＋ CaCO3 fine powder were used as starting materials,respectively,to prepare three microporous corundum aggregates specimens,named as A1,A2 and A3.Two lightweight Al2O3-MgO castables were prepared by selecting A1 or A3 as aggregate with O.6 μm of average pore size,then performances of castables with microporous corundum aggregates and castables with tabular corundum aggregates were compared.The results show that：（1） the microporous corundum aggregates with bulk density of 3.1-3.5 g · cm-3,apparent porosity of 5％,closed porosity of 8％-13％,and smaller thermal conductivity at 800 ℃ than tabular corundum,can be prepared by sintering at above 1 800 ℃ ; （2） compared to normal Al2 O3-MgO castables,the two lightweight Al2O3-MgO castables have lower bulk density and higher apparent porosity;lower change rate in dimensions and higher strength firing at 1 500 ℃ ; and lower thermal conductivity at 600 and 800 ℃ ; （3） compared to normal Al2O3-MgO castables,Al2O3-MgO castable with A1 has higher penetration index,and that with A3 has higher corrosion index and lower penetration index.     

Effect of Microsilica Addition on Properties of CMA72 Bonded Al_2O_3-MgO Castables

CMA72 bonded Al_2O_3-MgO castable is promising for application of steel ladle wall,because of unique combination of thermo-mechanical properties,slag corrosion resistance and cost benefit. In these castables,microsilica can be introduced to counterbalance the expansion generated by spinel formation. In this paper,the effect of microsilica dosage on properties of castables was evaluated. Expansion,expressed by the permanent linear change( PLC),is highly dependent on the dosage of microsilica. Unexpected expansion occurs when the dosage of microsilica is too low due to dominant effect of spinel and CA_6 formation. Too high dosage results in sintering shrinkage,which is related to amount of liquid phase generated by microsilica addition. In addition,HMOR declines dramatically with increasing microsilica dosage. Considering the balance between expansion control and hot property retention,1. 0 mass% of microsilica is recommended for the castable containing 4 mass%of magnesia.     

矾土基电熔锆刚玉粒度对Al2O3-MgO浇注料性能的影响

研究了不同粒度的矾土基电熔锆刚玉对Al2O3-MgO浇注料常规物理性能、高温机械性能及抗渣性的影响。结果表明：矾土基电熔锆刚玉细粉（〈0．074mm）或1-0mm颗粒的加入对Al2O3-MgO浇注料的常温性能和热震稳定性影响不大;而3～1mm锆刚玉颗粒的加入对浇注料的常温强度有负面影响,但明显提高了浇注料的抗热震性,浇注料的残余强度保持率显著提高。不同粒度矾土基锆刚玉的加入对浇注料的高温抗折强度和抗渣性能影响不大。     

Cr_2O_3在SiO_2-Al_2O_3-MgO-B_2O_3系玻璃和玻璃陶瓷中的作用

利用ＳＭＥ和ＸＲＤ等技术,系统研究了Ｃｒ２Ｏ３对ＳｉＯ２－Ａｌ２Ｏ３－ＭｇＯ－Ｂ２Ｏ３系玻璃和玻璃陶瓷中的作用。当Ｃｒ２Ｏ３％＜１时,随着Ｃｒ２Ｏ３。含量的增加,玻璃试样的颜色由浅绿色逐渐转变成灰色;Ｃｒ２Ｏ３％＞１时,镁铬（铝）类晶石,Ｍｇ（Ａｌ１．５Ｃｒ０．５）Ｏ４,在玻璃试样中析出;在玻璃陶瓷中,Ｃｒ２Ｏ３％的含量的增加有助于Ｍｇ（Ａｌ１．５Ｃｒ０．５）Ｏ４相的析出,对云母晶体的析出有抑制作用。同时还发现Ｃｒ２Ｏ３的含量对云母晶体显微组织也有显著的影响作用。     

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。     

富Al2O3区域Al2O3—Na2O—CaO—SrO系固态反应的研究

本文,用理学X-射线衍射仪研究了富Al_2O_3区域Al_2O_3-Na_2O-CaO-SrO系的固态反应。实验结果表明,煅烧过程固态反应的最终物相组成为Na_2O·11Al_2O_3、CaO·6Al_2O_3、SrO·6Al_2O_3与α-Al_2O_3共存。     

Al_2O_3基质做模板制备Ag_2S/Al_2O_3纳米复合物及表征

采用无污染的水热合成技术,对滴涂AgNO3的Al_2O_3模板煅烧相同时间不同温度、同一温度煅烧不同时间,制备了Ag_2S/Al_2O_3纳米复合物。用X-射线粉末衍射仪及扫描电镜对复合物的形貌进行了测试和表征,得出制备Ag_2S/Al_2O_3纳米复合物的优良条件。     

二氯甲烷在CrO3／Al2O3和Pd／Al2O3催化剂上的催化氧化

二氯甲烷在ＣｒＯ_３／Ａｌ_２Ｏ_３和Ｐｄ／Ａｌ_２Ｏ_３催化剂上的催化氧化张立庆（杭州应用工程技术学院化工系杭州３１００１２）姜玄珍，莫亦平（浙江大学化学系杭州３１００２７）关键词二氯甲烷；催化降解；负载型催化剂１引言随着有机化工，氯制品化工的迅速发展?..     

等离子喷涂制备TiC＋（A12O3／TiC）＋A12O3自愈合涂层

采用大气等离子喷涂方法在马氏体钢基体上制备TiC＋（Al2O3/TiC）＋Al2O3复合涂层。对涂层的抗热冲击性能、热氧化处理前后截面形貌及成分进行了分析,利用电化学方法测量涂层的耐腐蚀性能。结果表明,这种复合涂层在高温下具有良好的自愈合能力及抗热冲击性能,涂层样品在800、700、600℃和500℃下的抗热冲击次数分...     

Al_2O_3-SiC-C Bricks for Hot Metal Pretreatment

YB/T 164-1999 1 Scope This standard specifies the classification,technical requirements,test methods,inspection rules,packing,marking,transportation,storage and quality certificate of Al2O3-SiC-C bricks for hot metal pretreatment. This standard is applicable to Al2O3-SiC-C bricks for the inner lining of the hot metal pretreatment equipment such as torpedo cars and ladles.     

Al_2O_3对硼硅酸铅钙系玻璃性能的影响

用熔融法制备CaO-PbO-B2O3-SiO2系玻璃,以低温共烧法制备玻璃烧结体,研究不同Al2O3含量和烧成温度对玻璃的烧结性能和电性能的影响。结果表明:随着Al2O3含量的增加,玻璃的玻璃化转变温度升高,介电常数增加,介电损耗增加;X线衍射分析(XRD)显示G1玻璃在800℃析出CaSiO3和β-SiO2;G1玻璃于725℃保温30 min烧结,于10 MHz测试,介电常数(εr)=6.1,介电损耗(tanδ)=5.9×10-4;该玻璃有较低的玻璃化转变温度(tg=697.1℃)、较差的析晶能力、较低的介电损耗,适合作为低温共烧陶瓷(LTCC)的玻璃料使用。     

钢包用铝－尖晶石浇注料的研制

以矾土刚玉、烧结尖晶石、纯铝酸钙水泥为主要原料，添加少量ＳｉＯ２微粉和改性剂，研制出高档铝－尖晶石浇注料。铝－尖晶石浇注料中尖晶石的最佳含量为２０％，添加适量ＳｉＯ２微粉和改性剂，可显著改变材料的烧结性能，并可保证材料具有良好的体积稳定性和合适的膨胀值．该浇注料可广泛用于钢包壁和包底．     

板状碳化硅增韧氧化铝的T-曲线行为

用包络曲线法研究了板状碳化硅增韧氧化铝的Ｔ－ 曲线行为,结果是随着裂纹的扩展,其断裂韧性显著增加,直至平稳值约８ ．３ ＭＰａ·ｍ１／２ 。本文还探讨了材料的显微结构参数对材料增韧的影响,结果表明,板状碳化硅的增韧效果不仅取决于板状的取向,而且也取决于板状料的平均粒径、径厚比和粒径分布,在某些情况下,后者的影响更为显著。     

Comparative Study of Lightweight Corundum with Different Microstructures and Its Effect on Slag Resistance of Al_2O_3-MgO Castables

Corundum-spinel castables containing lightweight aggregates have drawn many attentions due to their potential for energy-saving,especially when applied in the high-temperature region,such as the work lining of refining ladle. One main aspect that restricts their application is the slag corrosion performance. In this study,one dense tabular corundum and three kinds of lightweight corundum were chosen as aggregates to prepare four different corundum-spinel castables. The slag resistance was compared through the induction furnace corrosion test. SEM-EDS,XRD,and thermodynamic and kinetics analysis were adopted for the discussion of the corrosion mechanism. Results show that the crystal grain size and shape of aggregates are important for the slag corrosion resistance of lightweight corundum-spinel castables under dynamic condition( enforced convection),yet the effects of pore characteristics are not dominated. Aggregates with large flake-like crystal grains show a thicker dissolution diffusion boundary layer and a lower dissolution rate,resulting in a favorable corrosion resistance of the castable. The poor microstructure of the aggregates,namely,larger pores and small and spherical grains,would cause deterioration of castables ' slag resistance.