熔融还原炉炉渣对镁铬耐火材料的蚀损

经检验在氩气气氛和１５００℃温度下,ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－Ｆｅ总Ｏ－Ｍ炉渣侵蚀镁铬耐火材料,所得结果简述如下：１）在静态条件下,ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－Ｆｅ总Ｏ－ＭｇＯ炉渣侵蚀镁铬耐火材料的主要形态包括表面的局部蚀损、耐火材料表面的孔状蚀损以及渣相本体蚀损。３）局部蚀损和孔状蚀损主要是由于表面应力沿着渣膜表面递减而形成的马栾哥尼对流所造成的。渣膜形成于局部蚀损的耐火材料试样上,或者耐     

CaO－Al_2O_3－SiO_2玻璃表面上晶体生长动力学和分相影响

ＣａＯ－Ａｌ＿２Ｏ＿３－ＳｉＯ＿２玻璃表面上晶体生长动力学和分相影响杨晓晶，李家治（中国科学院上海硅酸盐研究所２０００５０）许淑惠（西北轻工业学院７１２０８１）ＳｕｒｆａｃｅＣｒｙｓｔａｌＧｒｏｗｔｈＫｉｎｅｔｉｃｓｉｎＣａＯ－Ａｌ＿２Ｏ＿３－ＳｉＯ...     

Al_2O_3－SiC－C耐火材料在熔融还原熔体中的侵蚀

讨论了Ａｌ２Ｏ３－ＳｉＣ－Ｃ耐火材料在熔融还原熔体中的侵蚀机理．分析了铁浴式熔融还原熔体的性质、组成及种类和熔体的温度、熔体与耐火材料的相对运动速度以及ＳｉＣ加入量等因素对Ａｌ２Ｏ３－ＳｉＣ－Ｃ耐火材料在熔融还原熔体中侵蚀的影响，阐明了Ａｌ２Ｏ３－ＳｉＣ－Ｃ耐火材料在熔融还原熔体中的侵蚀特征及侵蚀机制。     

Si_3N_4-Al_2O_3-ZrO_2系陶瓷表面氧化层组成的EPMA分析

利用ＥＰＭＡ和ＸＲＤ的分析方法，研究了Ｓｉ＿３Ｎ＿４－Ａｌ＿２Ｏ＿３－ＺｒＯ＿２系陶瓷材料表面氧化层组成。结果表明，Ｓｉ＿３Ｎ＿４－Ａｌ＿２Ｏ＿３－ＺｒＯ＿２系陶瓷材料表面氧化层是由方石英相、ＺｒＳｉＯ＿４相和含有Ａｌ＿２Ｏ＿３、ＣａＯ等的ＳｉＯ＿２玻璃相所组成，其中ＳｉＯ＿２玻璃相中Ａｌ＿２Ｏ＿３、ＣａＯ等的含量，随着氧化时间的增加而逐渐增加。     

钢渣,粉煤灰微晶玻璃试制探讨

介绍利用钢渣、粉煤灰试制以Ｃａ（Ｆｅ、Ｍｇ）Ｓｉ２Ｏ６为主晶相的ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系微晶玻璃方法的原料、玻璃化学组成和热处理工艺。     

位于熔渣和金属界面的镁铬耐火材料的局部蚀损

研究了在１６００℃和氩气气氛下ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－Ｆｅ冲刷 Ｏ渣－－金属系统对镁铬耐火材料的侵蚀。所获得结果总结如下。（１）在静态条件下由的ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－Ｆｅ总Ｏ和金属引起的镁铬耐火材料的主要蚀损方式是在渣－－金属界面的局部蚀损。（２）在渣－金属界面的局部蚀损率是随着镁铬试样中的铁氧化物（ｅ２Ｏ３）含量和金属中的碳含量的增加而提高,并随着渣中的铁氧化物（Ｆｅ总）含量增加而     

SiC—Al2O3基复相陶瓷的N2—HIP研究

通过对热压ＳｉＣ－Ａｌ２Ｏ３复合材料进行了Ｎ２－ＨＩＰ后处理，制备得到Ｓｉ３Ｎ４－ＡｌＮ＝ＳｉＣ－Ａｌ２Ｏ３梯度材料，经Ｎ２－ＨＩＰ处理后，材料抗弯强度提高３５％－９５％，并得到经强度达１０３０ＭＰａ的ＳｉｅＮ４－ＡｌＮ／ＳｉＣｐ－ＳｉＣＷ－Ａｌ２Ｏ３复合材料。     

茂稀土／甲基甲氧基铝催化体系

用（Ｃ５Ｈ９Ｃｐ）２ＮｄＣｌ（Ｉ），（Ｃ５Ｈ９Ｃｐ）２ＳｍＣｌ（Ⅱ），（ＭｅＣｐ）２ＳｍＯＡｒ＇（Ⅲ，ＯＡｒ＇为对甲基－２，６－二特丁基苯氧基），（Ｉｎｄ）２ＮｄＣｌ（Ⅳ，Ｉｎｄ为茚基），Ｍｅ２Ｓｉ（Ｉｎｄ）２ＮｄＣｌ（Ⅴ）和（Ｆｌｕ）２ＮｄＣｌ（Ⅵ，Ｆｌｕ为芴基）分别与甲基甲氧基铝（ＭＡＯ）组成的催化体系，研究了丁二烯、异戊二烯和苯乙烯的聚合。结果表明，由（Ｉ）￣（Ⅲ）与ＭＡＯ组成的催化体系，可     

氮化硅结合碳化硅材料反应烧结时的杂质相行为分析

分析了Ｓｉ３Ｎ４结合ＳｉＣ材料反应烧结时Ｆｅ２Ｏ３，ＳｉＯ２，Ａｌ２Ｏ３，ＣａＯ等杂质相的反应行为。     

新型复相陶瓷刀具材料Jx-2-I协同增韧补强机理的研究

本文研制成功的新型陶瓷刀具材料—ＳｉＣ晶须（ＳｉＣｗ）增韧和ＳｉＣ颗粒弥散增韧Ａｌ２Ｏ３陶瓷刀具Ｊｘ－２－Ｉ,该刀具材料具有高的抗弯强度和断裂韧性等优点;对比Ａ（Ａｌ２Ｏ３）、ＡＰ（Ａｌ２Ｏ３／ＳｉＣｐ）、ＡＷ（Ａｌ２Ｏ３／ＳｉＣｗ）、Ｊｘ－１（Ａｌ２Ｏ３／ＳｉＣｗ）和Ｊｘ－２－１（Ａｌ２Ｏ３／ＳｉＣｐ／ＳｉＣｗ）等陶瓷材料的力学性能可以看出,在Ｊｘ－２－Ｉ材料中具有明显的增韧补强叠加效应;本文在热失配分析和微观结构观察的基础上详细研究了Ｊｘ－２－Ｉ刀具材料的增韧补强机理,系统研究了Ｊｘ－２－Ｉ中各种增韧补强机理之间的协同效应。     

Some Features of Leaching of Two-Phase Alkali Borosilicate Glass Containing PbO

The paper reports the results of a comparative investigation into the leaching kinetics of two-phase alkali borosilicate glasses containing lead oxide in 3 M HCl solution at 100°C and the glasses free from lead oxide. It is revealed that the mechanisms of leaching of the studied glasses exhibit a common feature which resides in the fact that the temporary precipitation of the products of dissolution of the glass components within the leached layer occurs as an intermediate stage of the glass leaching. Unlike glasses free from PbO, the precipitation within the porous layer of a leached lead-containing glass is observed visually, and the presence of crystalline boron-containing precipitates in this layer is confirmed by X-ray powder diffraction analysis. Compared to glasses prepared from two-phase alkali borosilicate glasses free from PbO, the porous glasses produced from two-phase glasses containing PbO are characterized by considerably smaller sizes of micropores and their larger specific surface at the same total porosity.     

Hydration and reaction mechanisms on sodium silicate glass surfaces from molecular dynamics simulations with reactive force fields

Recent development of reactive force fields have enabled molecular dynamics simulations of interactions between silicate glasses and water at the atomistic scale. While multicomponent silicate glasses encompass a wide variety of compositions and properties, one common structural feature in these glasses is the combination of the network structure that is made up of silica tetrahedra linked through corner sharing interspersed with network modifiers like alkali and alkaline-earth ions that break up the Si–O–Si linkages by forming nonbridging oxygen. In reactions with water, ion exchange between alkali ions in the glass and proton or hydronium in the solution, as well as hydrolysis reaction of the Si–O–Si linkages and subsequent silanol formation, is observed and well documented. We have used a set of recently developed reactive force field to investigate the reactions between water and the surfaces of silica and sodium silicate glasses of different compositions for reactions up to 8 nanoseconds. Our results indicate sodium leaching into water and diffusion of water molecules up to 25 Å into the glass surface. We examined the structural and compositional changes inside the glass and around the diffused ions and use these to explain the rates of silanol formation at the surface. We also observed proton transport in the glass which has an indirect influence on the silanol formation rates. While the surface of the glass was rough to start with, it undergoes further modification into a hydrated gel-like structure in the glass for up to 5 Å in the higher alkali containing glasses. It was found that the leached sodium ions remain close to the interface and that fragments of silicate network from the surface is capable of dislodging from the bulk glass and enter the aqueous solution. These simulations thus provide insights into the formation and structure of an alteration layers commonly observed in multicomponent silicate glasses corroded in aqueous solutions.     

Chemical Durability of Sodium Silicate Glasses Containing AI2O3 and ZrO2

A sodium silicate glass and ternary glasses derived from it by substituting AI₂O₃ and ZrO₂ for SiO₂ were exposed to water and aqueous solutions of pH 1.4 to 12.7; the kinetics of the reactions were studied. Diffusion of alkali ions and leaching of alkali and SiO₂ from the glasses were influenced by the occupancy of surface sites by alkali ions above a critical pH; however, the activation energies of the processes varied linearly with the logarithm of mole fraction of surface sites occupied by H^plus;. Identical slopes were obtained for all glasses for a given process. The results are explained on the basis that transport of alkali ions is retarded as a result of increased boundary concentration and that suitable sites for reaction are lacking.     

工业废弃物焚烧灰渣玻璃固化浸出离子浓度的研究

以工业废弃物焚烧产生的灰渣为主要原料,利用ICP和IC等测试手段,研究了不同配合料配比对玻璃在酸碱溶液中的重金属离子和阴离子浸出浓度的影响。实验结果表明:在p H=3和10的酸/碱性溶液中,原料的离子浸出浓度从1.45 mg/L和0.94 mg/L分别可下降到玻璃[D(1)-4]时的0.15 mg/L和0.024 mg/L;含氧化钙高的玻璃其铬离子浸出浓度[D(1)-4时的0.15mg/L]要低于含氧化铁高的玻璃[D(1)-6时的0.19 mg/L],而氯离子浸出浓度则相反(前者为0.075 mg/L,后者为0.042 mg/L)。玻璃的热膨胀系数、抗折强度和维氏硬度分别为78×10-6/℃、96 MPa和504 MPa。     

Internal Friction of Ion-Exchanged Li2O.Al2O3.2SiO2 Glass

Fibers of Li₂O.Al₂O₃.2SiO₂ glass were ion-exchanged for 1 to 300 min in an NaNO₃ bath at 366°C. The internal friction and the Li and Na concentration profiles were measured. As Na progressively replaced Li, the alkali internal friction peak became smaller while a new peak (mixed-alkali peak) appeared and increased in magnitude. These changes in internal friction are similar to those that occur when a second alkali is added to glasses prepared by conventional melting. The magnitudes of both internal friction peaks in the ion-exchanged glass depended on the overall composition of the glass; that of the alkali peak depended on the composition of the unexchanged glass core, whereas that of the mixed-alkali peak depended on the composition of the exchanged layer on the glass surface. When the exchanged surface layer was dissolved, the original alkali peak was restored, and the mixed-alkali peak disappeared. Changing the alkali distribution did not affect the mixed-alkali peak much; however, it caused the alkali peak to shift to higher temperatures and become smaller. The height of the alkali peak can be used to determine the maximum depth of penetration of the second alkali.     

Effect of Stress on Durability of Ion-Exchanged Surfaces

The leachability of ion-exchanged alkali alumino-silicate glasses in water and in acid was shown to be a function of the stress at the surface. Alkali aluminosilicate glasses formed by ion exchange under conditions resulting in surface compression were more durable than similar unstressed alkali aluminosilicate glasses melted from batch. Conditions which produced incomplete exchange at the surface, resulting in lower compressive surface stresses, led to a less durable glass surface. Where potassium from a salt bath was being exchanged for sodium in the glass, leachability was inversely proportional to the percent surface exchange.     

Heat of Annealing in Simple Alkali Silicate Glasses

The enthalpy changes associated with annealing of glass were studied in simple and mixed alkali silicate glasses. The data indicate that during prolonged annealing the glass comes to a metastable equilibrium state and has a unique heat of solution which depends on its fictive temperature. The heats of solution of these glasses show a linear dependence on fictive temperature, and the magnitude of this dependence is related to the molar volume of the glass. The significance of these heat effects is discussed. The maximum heat effects which can occur on annealing sodium silicate glasses were measured and were approximately half as large as the enthalpy changes associated with the structural arrangements that occur during crystallization of these glasses.     

SrO、La2O3、ZrO2对无铅水晶玻璃折射率,密度和耐碱性能的影响

熔融法制备不同氧化物含量的SiO2-B2O3 -R2O系无铅水晶玻璃,并表征了玻璃的密度、折射率和耐碱性能.结果表明:随着氧化锶含量的增加,玻璃密度、折射率和耐碱性能都随之增加;适量氧化镧(w(La2O3)≤22%)的加入可以提高玻璃的折射率、密度和耐碱性能,过量则反之;适量氧化锆的加入(w(ZrO2)≤28%)能够显著提高玻璃耐碱性能并提高玻璃折射率和密度,过多则促使玻璃析晶失透.     

La^3＋掺杂无碱铝硼硅酸盐玻璃性能的研究

以La2O3-Al2O3-B2O3-SiO2玻璃系统为基础玻璃,用SiO2替代B2O3,通过DTA、IR等测试手段来研究其介电性能、热稳定性、化学稳定性及结构的变化。玻璃红外光谱分析表明,该系统玻璃结构与未掺La2O3玻璃的结构相同;玻璃的DTA曲线表明,随着SiO2替代B2O3含量的增加,玻璃的软化点增高,析晶温度升高,玻璃的热稳定性得到增强;同时随着替代量的增加,玻璃的耐酸耐碱性也得到提高;介电常数及介电损耗在SiO2/B2O3=2.7时出现极小值。     

Physical performances of alkali‐activated portland cement‐glass‐limestone blends

The potential of calcium aluminosilicate (CAS) glasses as supplementary cementitious materials is studied in terms of the development of compressive strength for mortars containing a mixture of portland cement, CAS glass, and limestone. In addition, the impact of internal and external alkali activation of the cementitious systems on the mortar performances is investigated. Internal alkali activation is obtained by adding alkali oxides to the CAS glass system, whereas external alkali activation is realized by hydration of the blended cements containing alkali‐free CAS glasses using alkaline solutions. For the internally alkali‐activated systems and the alkali‐free mortars, higher strengths are achieved in comparison to the reference mortar prepared from plain ordinary portland cement. In contrast, the externally alkali‐activated mortars exhibit lower compressive strengths, implying the importance of both the immediate availability of alkali ions in the cementitious system and the increased dissolution rate of the glass particles caused by the network depolymerization. The glasses are also studied by thermal analysis and the results are used to calculate the theoretical CO₂ emissions. The lowest embodied CO₂ emission is estimated for the blends containing alkali‐activated CAS glasses.