基质组成对刚玉-尖晶石浇注料性能的影响

将Al2 O3-MgO系浇注料应用于钢包整体内衬的技术已经得到了肯定 ,特别是在刚玉质浇注料中添加部分预合成的尖晶石所制备的刚玉 -尖晶石浇注料 ,因其具有与炉渣的浸润性差 ,抗渣侵蚀性好 ,抗结构剥落性好等特点 ,正在成为世界各国钢包用耐火材料的主流。目前的研究分为两个方面 :一是刚玉-氧化镁体系 ,认为氧化镁含量的最佳范围为 8%～ 12 % ,此时材料具有优良的抗渣性能 ;二是刚玉 -尖晶石体系 ,认为浇注料中加入 2 0 %尖晶石时材料具有优良的抗渣侵蚀性和抗渣渗透性。本工作研究了氧化铝、氧化镁和尖晶石的加入比例对刚玉 -尖晶石浇注料…     

钢包用尖晶石-MgO浇注料的研究

随着钢包中二次精炼的不断采用，耐火材料上的负荷也在增加，其环境比以前更恶劣。基于此因，需要开发高性能的材料以延长生产时间，且耐高温及抗高C／S渣。通过采用粗尖晶石，新开发的尖晶石-MgO浇注料具有高抗侵蚀性和渗透性，比普通Al2O3-MgO浇注料性能要好。     

LF精炼钢包渣线用含铬铝镁浇注料的研制

以特级矾土、电熔镁砂、铬刚玉为主要原料制备了LF精炼钢包渣线用含铬尖晶石质浇注料,并在抗渣蚀性及抗热震性方面同现场使用的普通铝镁浇注料进行了对比。结果表明:与现场使用的铝镁浇注料相比,新研制的含铬尖晶石浇注料具有更好的抗热震性及抗渣蚀性,在济钢55t钢包上使用寿命达到79炉次。     

以微孔刚玉-尖晶石骨料替代刚玉骨料制备刚玉-尖晶石浇注料

为提高钢包工作衬用刚玉-尖晶石浇注料的保温性能，以微孔刚玉-尖晶石骨料部分或全部替代同粒级的烧结刚玉骨料，制备了刚玉-尖晶石浇注料，对比研究了不同骨料对浇注料的体积密度、气孔率、力学强度、热导率、抗渣性等的影响。结果表明：采用微孔刚玉-尖晶石骨料部分或全部替代同粒级的烧结刚玉骨料制备的刚玉-尖晶石浇注料，其体积密度和热导率均明显降低，抗渣性能与传统烧结刚玉骨料制备的浇注料相当。将其用于钢包工作衬，有助于钢包减重，提高钢包保温性能。     

涟钢钢包用耐火材料的改进

涟钢三炼钢厂钢包公称容量为 2 8ｔ,过去使用铝镁不烧砖修砌钢包 ,平均使用寿命仅为 5 0炉左右 ,而且渣线易产生穿包事故。从 1998年 9月开始试用铝镁尖晶石浇注料整体浇注钢包。经过一段时间的试用 ,钢包一次性平均使用寿命达 10 8次 ,吨钢耐火材料成本由原来的 15 .8元降低到 5 .90元 ,现已全面推广使用。1　浇注料的研制过程该厂曾先后于 1998年 9月及 1999年初与两个耐火材料研究单位合作 ,进行了铝镁尖晶石浇注料整体包衬浇注试验 ,因钢包在烘烤过程中易炸裂 ,使用时侵蚀严重 ,一次性寿命低而被淘汰。1999年 8月该厂又与河南某耐火材料…     

添加Cr2O3对不烧铝镁砖性能的影响

钢包包衬渣线部位需要使用具有优异抗侵蚀性的材料,一般使用镁碳砖。象镁尖晶石砖、镁铬砖等无碳碱性耐火材料也偶尔应用在钢包上,以阻止钢水增碳。这些无碳碱性砖抗渣渗透性差,这导致其结构剥落;然而,它们的抗渣侵蚀性好。作为典型无碳砖的不烧铝尖晶石砖在使用过程中原位形     

添加尖晶石超细粉提高铝尖晶石浇注料的抗侵蚀性

为提高钢包侧壁用浇注料的抗侵蚀性和抗潭渗透性,在对铝尖晶石质浇注料和铝镁质浇注料进行比较之后,研究了在铝尖晶石质浇注料中添加尖晶石超细粉的效果,调查了不同添加量所产生的影响,结果发现,尖晶石超细粉添加量为c%（质量）的铝尖晶石质浇注料不仅尖晶石在基质中均匀分散,而且组织致密,其抗侵蚀性和抗渣渗透性都比铝镁质浇注料的高,在实炉使用的结果表明,耐用性可提高大约３０％。     

AlON加入物对碱性浇注料抗渣性的影响

氧化镁氧化铝碱性浇注料一个弱点为抗渗透性差, 为改善钢包浇注料抗渣性能, 提高其使用效果和寿命, 运用静态坩埚法研究含AlON的MgO-Al2O3浇注料抗渣性.实验温度为1 600 ℃, 渣侵蚀时间为3 h.研究结果表明: 在还原气氛下, AlON取代浇注料基质中Al2O3能显著提高试样的抗渣侵蚀和抗渗透性. 在氧化气氛下, AlON对基质中Al2O3取代质量比不超过50%时, 抗氧化剂的加入有助于保持AlON优良的抗渣性, 产生这种结果的原因可归结于形成在高温下与氧化物渣难以润湿的含N尖晶石MgAlON, 从而延缓渣对浇注料的侵蚀和渗透.     

Al_2O_3-尖晶石浇注料抗侵蚀性的改进

Ａｌ2 Ｏ3 -尖晶石浇注料热膨胀率小 ,抗热剥落性好 ,高温强度高 ,但由于它抗渣侵蚀、渗透性差 ,限制了它在钢包侧壁上的普遍使用。为改善Ａｌ2 Ｏ3 -尖晶石浇注料的抗侵蚀和抗渗透性 ,研究了添加尖晶石超细粉和骨料的影响。当在浇注料中加入超细尖晶石粉 (平均粒径 1.1μｍ)时     

日本钢包用优质浇注料内衬

近年来，日本钢包广泛使用铝－镁浇注料与铝－尖晶石浇注料。然而这两种浇注料在结构稳定性，抗侵蚀性与抗渣渗透性方面有所不同。因此在设计浇注料内衬时，必须考虑一定的条件和损毁机理。     

钢包渣线用镁锆铬质无炭浇注料的研制

精炼钢包渣线使用含炭耐火材料存在着使钢水增碳的问题 ,需要研制抗渣侵蚀和渗透能力较强的无炭钢包渣线材料。以轻烧氧化镁和锆英石为原料 ,采用湿法共磨工艺 ,合成了镁锆质熟料 ,并以此合成料为主要原料 ,加入工业Cr2 O3细粉、锆英石细粉及硅微粉等研制了无炭的镁锆铬质钢包浇注料。实验证明 ,制得的镁锆铬质浇注料高温强度较高 ,高温收缩率较小 ,抗渣侵蚀和渗透能力较强。     

Structure and properties of lightweight magnesia refractory castables with porous matrix

To improve the energy-saving capacity of magnesia refractory castables for working lining of high-temperature kilns, this study presents the researches on microstructure and properties of lightweight magnesia refractory castables with porous matrix fabricated by direct foaming method. The results show that formation of closed-pores in the matrix significantly enhanced high-temperature thermal insulation performance of castables with minor changes of slag corrosion resistance. The thermal conductivity of the lightweight magnesia castables at 1000 °C was below 1.2 W/m·K, which is 47.8% lower than that of the referenced magnesia castable. The increasing content of SDS (foaming agent, over 0.02 wt%) led to increments of size and number of large-sized pores, resulting in the significantly decreased density and mechanical performances. The slag resistance mechanism reveals that, in addition to intergranular penetration, the accumulation of slag and penetration between adjacent pores were the major ways of slag mass transfer in lightweight magnesia castables. In conclusion, controlling the size (below 53.2 μm), number and distribution of closed-pores in the matrix is effective to realize the coupling of high thermal insulation, mechanical properties and slag resistance for lightweight magnesia castables used in the metallurgical field.     

Effect of carbon black on corrosion resistance of Al2O3–SiC–C castables to SiO2–MgO slag

Metallurgical solid waste recycling is the shape of things to come in green development of Chinese iron and steel industry. Utilization of ironworks slag for producing mineral wool at high temperature is an important approach. However, refractory lining is seriously corroded by the SiO₂–MgO based slag at 1600 °C during the production process. Different production steps need different atmospheres, the changeable service atmospheres (air and reducing atmosphere) put forward high requirements for slag resistance. The Al₂O₃–SiC–C castables containing carbon black are usually used in iron runner, which faces high-temperature service condition of 1450 °C–1500 °C. Nevertheless, the function of carbon black in the Al₂O₃–SiC–C castables at 1600 °C is till essentially unknown. In the current study, the carbon black was introduced to tabular alumina based Al₂O₃–SiC–C castables to improve corrosion resistance to SiO₂–MgO based slag at 1600 °C. The result showed that 0.4 wt% carbon black was suitable for the castables, which the slag resistance of castables was significantly improved. The carbon black had contributed to block slag by wettability resistance. By comparison with the castables without carbon black, the corrosion index and penetration index had been reduced by 20.2% and 28.0%, respectively, under air atmosphere. And there were little corrosion or penetration under reducing atmosphere for castables with 0.4 wt% carbon black. For the mechanical properties, the Al₂O₃–SiC–C castables with 0.4 wt% carbon black could serve production process although the carbon black impaired the physical properties.     

Effects of aggregate microstructure on slag resistance of lightweight Al2O3-MgO castable

Corundum-spinel castables using lightweight aggregate have drawn much attention due to their energy-saving potential, in particular when they are applied in high-temperature areas, such as the work lining of refining ladle. One of the main issues which hinder their application is their relatively poor slag corrosion performance. In this study, one type of dense tabular corundum and three types of lightweight corundum were chosen as aggregates to prepare four different model corundum-spinel castables. Their slag resistance was evaluated by an induction furnace corrosion test method. As well as SEM, EDS, and XRD characterizations, thermodynamic and kinetic analyses were carried out to assist understanding the corrosion mechanism. Results indicated that size and shape of crystalline grain in aggregate were important for the slag corrosion (dissolution) resistance of lightweight corundum-spinel castables under dynamic condition (enforced convection), whereas the effects of pore characteristics were not significant. Use of aggregates having large average crystal size and flake-shaped crystals led to a thicker diffusion boundary layer and lowered dissolution rate, i.e., good corrosion resistance, whereas use of aggregates with small and spherical crystals and larger pores led to poor slag resistance.     

基质组成对MgO-尖晶石浇注料抗渣性能的影响

采用静态坩埚法研究了添加不同组成尖晶石的ＭｇＯ－ 尖晶石浇注料基质组成与抗渣性能的关系。实验结果表明：随着基质中Ａｌ２Ｏ３ 含量增加,浇注料抗渣侵蚀能力减弱,而抗渣渗透能力增强。在基质中ＳｉＯ２ 含量固定在１０ ％ 的情况下,基质中Ａｌ２Ｏ３ 含量在３０ ％ ～５０ ％ 时浇注料抗渣侵蚀性能较好;Ａｌ２Ｏ３ 含量超过５０ ％ 时,侵蚀速率急剧增加两倍以上。不同组成尖晶石对浇注料抗渣侵蚀性能没有明显影响,但含富铝尖晶石的浇注料具有较好的抗渣渗透性能。     

Preparation and characterization of HA bonded Al2O3–MgO based castables with superior slag resistance for the working lining of Si-killed stainless steel ladles

The study prepared Al₂O₃–MgO based castables bonded by hydratable alumina (HA) instead of calcium aluminate cement (CAC) for the working lining of Si-killed stainless steel ladles. The microstructure, phase composition, mechanical properties, and slag resistance of castables were investigated by SEM, XRD, and thermodynamic software FactSage®. The results indicated that the HA bonded castables showed superior hot flexural strength, thermal shock resistance and slag resistance than the CAC bonded castables, due to the optimized pore characteristics, less liquid content, and higher liquid viscosity of the castable matrix and the formation of a continuous insulating layer.     

锆英石和氧化铝加入量对镁质浇注料性能的影响

研究了锆荚石和氧化铝的加入量对镁质浇注料常温物理性能、热震稳定性、高温抗折强度（１４５℃,１ｈ）及抗渣性能的影响。结果表明：锆英石和氧化铝的加入均降低了镁质浇注料的常温强度,提高了其热震稳定性,但对高温抗折强度影响不大;适量锆英石和氧化铝的加入均能改善镁质浇注料的抗渣渗透性。     

Al2O3-SiC-C耐火材料抗CaO-SiO2-K2O渣侵蚀性能研究

研究了Al2O3-SiC-C耐火材料的抗CaO-SiO2-K2O渣侵蚀性能,以及添加Cr2O3对Al2O3-SiC-C材料抗渣侵蚀性能的影响.研究结果表明CaO-SiO2-K2O熔渣对Al2O3-SiC-C材料具有明显的侵蚀作用;在Al2O3-SiC-C材料中添加适量的Cr2O3可以有效地抑制CaO-SiO2-K2O熔渣向耐火材料内部的渗透,降低耐火材料的侵蚀速度.     

The physical and mechanical properties of alumina-based ultralow cement castable refractories

In this study, the effects of the type of alumina on the physical, chemical and mechanical properties of the ultralow cement castable (ULCC) refractories were investigated. Brown fused alumina, tabular alumina and rotary bauxite-based ULCC refractories were prepared by mixing each type of alumina with silicon carbide, carbon, cement, metallic silicon and microsilica. The density, porosity and cold crushing strength (CCS) of the refractory castables were measured after drying at 110 °C for 24 h and firing at 1450 °C for 5 h. The slag penetration resistance of the refractory castables was determined using slag corrosion tests. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffractometry (XRD) were used to characterize the castables. It was found that all three refractory castables had strong slag penetration resistance and that the tabular alumina-based refractory castable had the largest specific cold crushing strength with an acceptable percent of porosity among the refractory castables.     

Slag Resistance of Refractories for Direct Reduction of Laterite Nickel Ores in Rotary Kilns

Aiming at prolonging the service life of refractories for direct reduction of laterite nickel ores in rotary kilns, the slag resistance of ten materials(corundum bricks, chrome corundum bricks, silicon nitride bonded silicon carbide bricks, high alumina silicon carbide bricks, high alumina bricks, magnesia chrome bricks, magnesium aluminate spinel bricks, spinel chrome corundum bricks, chrome corundum castables and magnesia alumina chrome composite spinel bricks) was evaluated by rotary slag tests, which simulate the service conditions in rotary kilns. The corroded residual bricks were analyzed by SEM and EDS. The results show that the magnesia alumina chrome composite spinel brick possesses the advantages of magnesium aluminate spinel bricks and chrome corundum bricks; MgO-rich spinel can absorb the penetrated ferric oxide, and forms a dense zeylanite layer, which prevents the penetration of the molten laterite nickel ores; therefore, it is an ideal lining of rotary kilns for direct reduction of laterite nickel ores.