熔融还原型熔体与Al2O3—C质耐火材料的相互使用

采用旋转法研究了不同条件下熔融原型熔体与Ａｌ２Ｏ３－Ｃ质耐火材料间的化学作用规律和相互作用机制及结构变化。结果表明，熔渣中ＦｅＯ和耐火材料的碳作用产生脱碳是耐火材料侵蚀的关键环节。尔后形成的低熔点化合物使耐火材料继续侵蚀，添加ＺｒＯ２可提高耐火材料的抗侵蚀能力。     

高铝低硅CaO-Al2O3系熔渣对刚玉/六铝酸钙质浇注料的作用行为

摘要：由于高铝低硅CaO-Al2O3系熔渣对耐火材料的侵蚀损毁影响高铝含量低密度高强钢的安全冶炼生产,为此通过在刚玉质浇注料中引入六铝酸钙,开展六铝酸钙质浇注料与高铝低硅CaO-Al2O3系熔渣反应实验,并与铝镁浇注料进行对比研究了其作用行为。实验结果表明：刚玉 六铝酸钙浇注料具有优异抗渣性能。这主要是由于熔渣中大量的CaO被消耗,间接提高了熔渣黏度,并与刚玉 六铝酸钙浇注料反应生成的高熔点相CA2填充了气孔,阻挡了熔渣的渗透,实验结果与热力学模拟计算结果相吻合。六铝酸钙浇注料自身气孔率高,熔渣主要以渗透形式对六铝酸钙耐火材料造成破坏。因此,将刚玉骨料与六铝酸钙基质组合是有望成为低密度高强钢冶炼用钢包内衬候选耐火材料。     

危废焚烧炉渣对耐火材料侵蚀的试验研究

本研究选取铬刚玉、镁铬刚玉和烧结锆刚玉3种不同材质的耐火砖,在不同酸碱熔渣环境下进行侵蚀试验并探索侵蚀成因。结果表明,酸性熔渣环境下,铬刚玉砖抗侵蚀性能较好,镁铬刚玉砖侵蚀较为严重,烧结锆刚玉砖侵蚀明显;随温度升高、时间延长,铬刚玉砖的抗侵蚀性能最优,镁铬刚玉砖抗侵蚀性能、抗热膨胀性能均较差,烧结锆刚玉砖侵蚀最严重;中性熔渣环境下,铬刚玉砖抗侵蚀性能降低,侵蚀状况略微明显,镁铬刚玉砖侵蚀状况相对较好,液面线上方出现了一定程度的裂缝,烧结锆刚玉砖侵蚀速度较快,液面线处出现明显“凹槽”;碱性熔渣环境下,铬刚玉砖表面被侵蚀恶化明显,镁铬刚玉砖侵蚀状况不明显,烧结锆刚玉砖被侵蚀明显。对侵蚀成因进行分析发现,侵蚀是由焚烧炉渣原渣中含有的Na₂O非晶态矿物、结晶态石英和外加钙质氧化物与耐火材料中化学成分发生反应导致的,侵蚀速度与耐火材料化学成分有关。     

高炉炉缸用Al2O3-SiO2-SiC浇注料抗渣铁侵蚀机制研究

对2种浇注料在实验室和现场情况下进行熔渣和铁水侵蚀研究。采用扫描电镜-能谱分析等方法对浇注料的侵蚀部分进行表征,明晰其侵蚀机制,并为高炉炉缸浇注料的合理选用、优化等提供理论参考。结果表明：浇注料的抗铁水侵蚀性能较好,且浇注料2的抗铁水侵蚀性能优于浇注料1;浇注料的抗熔渣侵蚀性能较差,浇注料1的抗熔渣性能远优于浇注料2。浇注料被铁水侵蚀是通过铁水的渗透、冲刷和硅化合物的反应形成的。浇注料被熔渣侵蚀是通过浇注料的溶解、熔渣的渗透和两者界面处发生的反应进行的。硅化合物会通过与铁液发生反应促进铁水侵蚀浇注料,氧化铝则对渣侵蚀浇注料的影响较大。在高炉运行过程中,浇注料1的使用价值超过浇注料2,更适合应用于铁口中心线下的炉缸侧壁处。     

通过循环渣试验对高铝耐火材料抗侵蚀性及显微结构的讨论

本文详尽介绍Cr_2O_3对高铝耐火材料的影响及其蚀变蚀损机理。就抗侵蚀性及显微结构,对四种普通高铝耐火制品和两种含铬高铝耐火制品进行鉴定。循环渣试验后对耐火材料进行了各种分析,结果表明:含铬产品的抗渣性优于不含铬产品。有三个论据支持这一结论。其中包括:1.渣/砖界面形成的铬——尖晶石;2.界面下形成的不渗透莫来石层;3.铬—铝固溶体的形成改进了基质结合。     

CaO-Al2O3-SiO2系渣中Al2O3含量对铝镁质浇注料侵蚀的影响

摘要：钢中添加适量铝元素可以提高其韧性与耐腐蚀性,但在冶炼过程中会影响炉渣中Al2O3含量而改变其与现行铝镁质浇注料的界面反应,制约钢种冶炼及品质提升。因此,采用静态坩埚法开展铝镁质浇注料的抗CaO-Al2O3-SiO2渣蚀实验,并结合热力学模拟计算探究Al2O3含量（w(CaO)∶w(Al2O3),C/A）变化对耐火材料渣蚀的影响规律,得到以下结论：随着熔渣中Al2O3含量的增加,铝镁质浇注料与熔渣反应界面越易形成更厚的高熔点隔离层,将耐火材料组分向熔渣中的直接溶解转变为间接溶解,有利于提升铝镁质浇注料的抗侵蚀性;当渣中的Al2O3质量分数在32%左右时,熔渣的侵蚀性总体较弱,但当渣中的Al2O3质量分数不小于36%时,熔渣对铝镁质浇注料产生了严重的渗透性,也易造成材料变质剥落。这为面向含铝钢冶炼用耐火材料的优化设计提供参考。     

熔融还原型熔体与Al_2O_3－C质耐火材料的相互作用

采用旋转法研究了不同条件下熔融还原型熔体与Ａｌ＿２Ｏ＿３－Ｃ质耐火材料间的化学作用规律和相互作用机制及结构变化。结果表明，熔渣中ＦｅＯ和耐火材料的碳作用产生脱碳是耐火材料侵蚀的关键环节。尔后形成的低熔点化合物使耐火材料继续侵蚀。添加ＺｒＯ＿２可提高耐火材料的抗侵蚀能力。     

尖晶石的合成及应用

镁铝尖晶石耐火材料具有高的抗金属溶液和碱性氧化溶液侵蚀的性能,因此被广泛用于黑色冶金和有色冶金工艺设备的工作衬。如钢水炉外真空处理,精炼钢包内衬,钢锭浇注,也可用于水泥回转窑烧成带,玻璃窑炉格子砖等。本文将简要介绍镁铝尖晶石     

电场对耐火材料抗渣侵蚀性能影响的研究进展

熔渣侵蚀是造成耐火材料损毁的主要原因之一，而外加电场近年来被证实可通过改变熔渣的物化性质来影响耐火材料的抗渣侵蚀性能。综述了外加电场对熔渣黏度、接触角、界面张力、物相组成和结晶行为等物化性质的影响，总结了外加电场影响耐火材料抗渣侵蚀性能的机理。此外，简要归纳了外加电场技术在抑制耐火材料侵蚀方面存在的缺陷和不足之处，并对外加电场技术未来的发展方向进行了展望。     

铁浴熔融还原炉长寿化技术研发与实践

HIsmelt熔融还原工艺具有工艺流程短、原料适用性强、产品纯净度高等特点，因采用较高的二次燃烧率，使得熔渣中含有较高的FeO含量，易侵蚀炉缸耐材。结合山东墨龙HIsmelt商业化工厂的技术研发与实践，介绍了该HIsmelt工厂建设情况和熔融还原工艺特点，并重点对耐火材料研发、炉衬结构优化和冷却装置创新方面进行了分析。结果表明：采用铝铬砖提高了耐材渣线区域的抗侵蚀能力，更加适合炉内的冶炼环境；渣区冷却器的设计增强了耐材上部炉渣的冷却强度，有助于减轻炉渣对耐材的侵蚀；虹吸出铁的工艺操作，使得熔融还原炉出铁工艺更加灵活可靠。耐火材料使用寿命的提高，对于熔融还原炉长期安全、稳定和高效运行具有重要意义。     

CaO-La2O3-B2O3-Eu2O3转光玻璃的合成及荧光性质

X射线衍射研究表明CaO-La2O3-B2O3-Eu2O3体系的玻璃化温度在1025℃附近。荧光光谱和ESR谱研究表明,在CaO-La2O3-B2O3-Eu2O3玻璃体系中存在着Eu2 和Eu3 两种价态离子。316,360,379,394,413,462和532nm锐线激发峰和592,616和650红区发射峰分别对应Eu3 的f-f激发跃迁和5D0-7FJ(J=1,2,3)跃迁发射;351nm和427nm宽带激发峰和蓝区发射分别对应Eu2 的5d-4f激发跃迁和发射。     

Vitrification and Crystallization Behavior of CaO-SiO2-MgO-Al2O3-Fe2O3-Cr2O3 System

Metallurgical and Materials Transactions B - The effect of basicity and Cr2O3 content on vitrification of the CaO-MgO-SiO2-Al2O3-Fe2O3-Cr2O3 system during a melt-quenched process and the...     

Wettability of silicon carbide ceramic by Al2O3/Dy2O3 and Al2O3/Yb2O3 systems

Wettability is an important phenomenon in the liquid phase sintering of silicon carbide (SiC) ceramics. This work involved a study of the wetting of SiC ceramics by two oxide systems, Al₂O₃ /Dy₂O₃ and Al₂O₃ /Yb₂O₃, which have so far not been studied for application in the sintering of SiC ceramics. Five mixtures of each system were prepared, with different compositions close to their respective eutectic ones. Samples of the mixtures were pressed into cylindrical specimens, which were placed on a SiC plate and subjected to temperatures above their melting points using a graphite resistance furnace. The behavior of the melted mixtures on the SiC plate was observed by means of an imaging system using a CCD camera and the sessile drop method was employed to determine the contact angle, the parameter that measures the degree of wettability. The results of variation in the contact angle as a function of temperature were plotted in graphic form which showed that the curves displayed a fast decline and good spreading. All the samples of the two systems presented final contact angles of 40° to 10° indicating their good wetting on SiC in the argon atmosphere. The melted/solidified area and interface between SiC and melted/solidified phase were evaluated by scanning electron microscopy (SEM) and their crystalline phases were identified by X-ray diffraction (DRX). The DRX analysis showed that Al₂O₃ and RE₂O₃ reacted and formed the Dy₃Al₅O₁₂ (DyAg) and Yb₃Al₅O₁₂ (YbAg) phases. The results indicated that the two systems had a promising potential as additives for the sintering of SiC ceramics.     

Al_2O_3La_2O_3Y_2O_3/Cu复合材料的电弧侵蚀特性研究

采用喷射沉积和内氧化法制备出Al2O3La2O3Y2O3/Cu复合材料,研究该材料在直流20 V/20 A的工作条件下触点的电弧侵蚀特性,并与Al2O3/Cu材料进行了对比分析.利用电子天平、扫描电镜等方法分析电弧侵蚀后触点的质量变化和表面微观结构.结果表明,通过添加Y2O3、La2O3稀土氧化物颗粒,可有效降低触头材料的材料转移量.Al2O3La2O3Y2O3/Cu材料的抗熔焊性和抗烧损性优于Al2O3/Cu材料的性能.在直流阻性负载条件下Al2O3La2O3Y2O3/Cu阳极触头表面形成凹坑,阴极触头表面形成凸起,触点表面显示出浆糊状凝固物和喷发坑等电弧侵蚀形貌特征.     

Viscosity of CaO-SiO2-Al2O3-MgO-B2O3 slags

The viscosity of CaO-SiO₂-Al₂O₃ slags with 8% MgO and 4% B₂O₃ is investigated over a broad range of composition, by means of a simplex-lattice experiment design. For slag of basicity 6–8 in the upper left region of the local simplex, with 15–25% Al₂O₃, 8% MgO, and 4% B₂O₃, the viscosity is high: 9.4–26.4 P over the range 1500–1530°C. Displacement of the slags of basicity 5–8 to the lower region of the local simplex ensures high fluidity in the given range of Al₂O₃ concentration: the viscosity is 1.5–6.1 P over the range 1500–1530°C.     

Research on Glass Forming Ability of Er2O3 -Al2O3 -B2O3 -SiO2 System

The glass forming range of Er2O3-Al2O3-B2O3-SiO2 system was explored, and the effect of the content of Al2 O3 and Er2 O3 on glass-forming region was experimentally examined. It is shown that the region of glass formation range expends when the content of Al2O3 is changed from 15% to 20%, while it shrinks when the content of Er2O3 is changed from 20% to 30%. At the same time, the glass forming ability of Er2O3-Al2O3-B2O3-SiO2 system was also discussed using a value of β, which is an indication of crystallization tendency of glasses, calculated from thermo-analysis data. It is found that the glass forming ability of Er2O3-Al2O3-B2O3- SiO2 glasses is poor, while the glasses network may be enhanced when Al2O3 is added to the system, the glass forming ability being heightened. In addition, the crystallization temperatures of the rare earth glasses were determined using differential thermal analysis technique. The Er2O3-Al2O;-B2O3-SiO2 glass samples were heat treated at 1000,1100 and 1260℃ respectively. The results show that it is the Er2O3 phase that separates out from the glasses after crystaline heat treatment, and it is tiered up in glasses, as detected through XRD and SEM. This indicates that the phase separation occurs when the glasses are heated, Er3 being mainly distributed in the boron rich phase, then separated out from glasses, while the silicate rich phase remaining glassy state.     

Stability of Fluorine-Free CaO-SiO2-Al2O3-B2O3-Na2O Mold Fluxes

Metallurgical and Materials Transactions B - B2O3 and Na2O are key components of fluorine-free mold fluxes for continuous casting, but both are highly volatile, which affects the flux stability....     

X射线荧光光谱法测定Dy_2O_3及其杂质Eu_2O_3,Gd_2O_3,Tb_4O_7,Ho_2O_3,Er_2O_3和Y_2O_3

当前稀土应用范围越来越广,尤其Dy2O3和金属Dy其出口量不断增大．Dy2O3中所含杂质总量通常在0．1％～5％之间,该范围内的测定方法以XRFR为合适,快速、准确、无破坏．1实验部分1．l原理本法采用粉末直接压片法制样,在各元素分析线峰位上测量X射线强度,根据待测元素的X射线荧光光谱强度与含量的定量关系,选择相应的数学模型,由计算机自动计算出待测成份含量．1．2仪器和试剂荷兰飞利浦PW—1400顺序式X射线荧光光谱仪;康柏486计算机;电动小型油压机;万分之一精度分析天平．DyZO399．999％;EnD3,GdD3,ThAn,HoAn,ErD3…     

Solid-phase reactions of Ta2O5 with Ga2O3 and In2O3

Conclusions Using the techniques of DTA and x-ray phase analysis, a study was made of the reactions between Ta₂O₅ and M₂O₃ (M = Ga or In), and the phase compositions of the relevant binary systems were determined. The existence was confirmed of stable compounds of composition MTaO₄ and eutectoidally decomposing phases containing 7.5–12.5 mole % M₂O₃. MTaO₄ are dielectrics, whose room-temperature _v is of the order of 10¹⁰ -cm. The temperature dependence of _v of MTaO₄ was investigated in the range 293–873°K and their energies of activation for conductivity were calculated. The melting points, pyknometric densities, dielectric losses, and relative dielectric permeabilities of MTaO₄ were determined.Translated from Poroshkovaya Metallurgiya, No. 2 (110), pp. 69–73, February, 1972.     

镁砂中Fe2O3、Al2O3、P2O5、TiO2的联合测定

镁砂产品检验中,采用碱熔融法共同预处理样品,在同一母液中,联合测定铁、铝、磷、钛的含量,缩短了检测时间。通过分别控制各元素的显色酸度,各元素线性良好,测得的Fe2O3、Al2O3、P2O5、TiO2的相对标准偏差分别小于1.11%、2.78%、4.84%、5.88%。实验结果表明,方法的准确度和精密度都较高。