氧化锰在锰铁渣中的热力学活度及金属与渣相间锰的分布

研究了埋弧炉锰铁生产中由ＭｎＯ－ＣａＯ－ＭｇＯ－ＳｉＯ２－Ａｌ２Ｏ３组成的标准炉渣。渣中Ａｌ２Ｏ３含量固定在５％。本研究目标集中在１５００℃时锰铁渣中ＭｎＯ的热力学活度上。为了达到校准的目的，在１３００、１４００和１５００℃时重新测定了Ｍｎ在Ｐｔ－Ｍｎ合金中的热力学活度。在１５００℃ＣＯ气氛下研究了碳饱和的Ｍｎ－Ｓｉ－Ｆｅ－Ｃ合金与ＭｎＯ－ＣａＯ－ＭｇＯ－ＳｉＯ２－Ａｌ２Ｏ３渣之间的平衡。在试验中发现，ａＭｎＯ值随着ＭｎＯ的增加而增大，趋向于随ＣａＯ／ＭｇＯ比的增大而增大。ａＭｎＯ值也随着碱度的增大而增大。在渣－金属平衡试验中，金属相中碳和硅的含量为反比关系。当硅含量一定时，由于Ｍｎ／Ｆｅ比增加，碳在金相中的溶解度增加。金属中含硅量随着渣中ＳｉＯ２含量的增加而增加．以及当ＭｇＯ代替渣中的ＣａＯ时，金属中含硅量增加。增大渣碱度使金属相含硅量降低。     

CaO—Al2O3—SiO2三元渣对硬线钢的脱氧热力学计算

针对硬线钢,研究了ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２三元渣系的脱热力学,根据渣－金平衡,计算了１８２３Ｋ下脱氧平衡时的（Ａｌ）,（Ｏ）,ＭｎＯ以及ＦｅｔＯ的等浓度线。     

CaO-SiO2-Fe2O3-MnO2-MgO-P2O5系熔剂对钢液脱磷、回磷的实验研究

在１８５３Ｋ的温度下,利用ＣａＯ－ＳｉＯ２－ＦｅＯ３－ＭｎＯ２－ＭｇＯ－Ｐ２Ｏ５系熔剂,对钢液进行脱磷、回磷实验,研究熔剂碱度ＣａＯ／ＳｉＯ２和氧化性（Ｆｅ２Ｏ３＋ＭｎＯ２）对钢液脱磷、回磷的影响,研究得出,防止钢液回磷的先决条件是：控制熔剂碱度和氧化性大于其临界值。实验发现,用适量ＢａＯ取代ＣａＯ基熔剂中的ＣａＯ,可有效控制钢液的回磷。     

CaO—Al2O3—CaF2—SiO2—MgO五元精炼渣系的起泡性能

采用二次回归正交试验方法测定了１５３０℃下ＣａＯ－Ａｌ２Ｏ３－ＣａＦ２－ＳｉＯ２－ＭｇＯ五元精炼渣系的起泡性能。得出炉渣起泡指数与炉渣光学碱度、渣中Ａｌ２Ｏ３及ＣａＦ２含量间的回归方程。结果表明：炉渣的光学碱度和ＣａＦ２含量对起泡指数有较大影响,而Ａｌ２Ｏ３含量对起泡指数影响很小。具有最佳发泡性能的炉渣成分中ＣａＯ,Ａｌ２Ｏ３,ＣａＦ２,ＳｉＯ２,ＭｇＯ的质量分数分别为：４４．０６％,３０．００％,７．００％,８．９４％,１０％。研究结果还表明：炉渣起泡指数与炉渣粘度成正比,而与表面张力和密度的平方根成反比。     

CaO—SiO2—MgO—Al2O3精炼渣的脱硫性能

在实验室用模拟装置研究了ＣａＯ－ＳｉＯ２－ＭｇＯ－Ａｌ２Ｏ３精炼渣脱硫的性能。碱度和助溶剂ＣａＦ２含量对硫分配比Ｌｓ影响较为显著，并分析了ＭｇＯ、Ａｌ２Ｏ３对脱硫反应的作用。     

LF（钢包炉）固体合成渣脱硫工业性试验研究

以３０ｔＥＢＴ超高功率电炉为初炼炉和４０ｔＬＦ（钢包炉）作为精炼炉，使用ＣａＯ－ＣａＦ２系固体合成渣对Ｑ２３５钢进行钢包炉内脱硫工业试验，在本试验条件下，当ＥＢＴ电炉初炼钢液（Ｓ）初＝０．０３５％～０．０８１％时，最佳精炼渣碱度Ｒｂ＝（％ＣａＯ）／（％ＳｉＯ２）为２．０～２．６或Ｒｆ＝（％ＣａＯ）＋（％ＭｇＯ）／（％ＳｉＯ２）＋（％Ａｌ２Ｏ３）为１．５～２．０，渣指数（ＣａＯ）／（ＳｉＯ２）：（Ａ     

钢包炉（LF）CaO－SiO_2－MgO－Al_2O_3渣系的脱硫试验

钢包炉（ＬＦ）ＣａＯ－ＳｉＯ_２－ＭｇＯ－Ａｌ_２Ｏ_３渣系的脱硫试验郭上型，万真雅（华东冶金学院，马鞍山２４３００２）ＤｅｓｕｌｐｈｕｒｉｚｉｎｇＴｅｓｔｕｓｉｎｇＣａＯ－ＳｉＯ_２－ＭｇＯ－Ａｌ_２Ｏ_３ＳｌａｇｉｎＡＬａｄｌｅＦｕｒｎａｃｅ￥ＧｕｏＳ...     

含MnO高炉型钛渣表面粘度和体相粘度的测定

本文用较严格的实验方法，研究测定了在中性、还原条件下ＭｎＯ－ＴｉＯ２－ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－ＭｇＯ六元渣系的表面粘度和体相粘度值。详细考察了各组成分对炉渣性质的影响。实验结果表明：无论在中性还是在还原条件下，渣中ＭｎＯ含量增加、碱度（ＣａＯ／ＳｉＯ２）提高、碱度（ＣａＯ／ＳｉＯ２）提高，可使炉渣的表面粘度、体相粘度降低。在中性条件下，渣中ＴｉＯ２含量的增加，可使炉渣的表面粘度、体相粘度降低     

CaO—SiO2—Al2O3—MgO—TiO2渣系熔副还原过程中钛还原行为的研究

在实验室条件下，探讨了铁浴法熔融还原过程中，在ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－ＭｇＯ－ＴｉＯ２渣系与碳饱和熔铁间钛的还原行为，以及渣中ＴｉＯ２含量，熔渣碱度（ＣａＯ／ＳｉＯ２），还原温度，铁浴量等因素对钛还原的影响。     

高速连铸保护渣的粘性特征

采用ＣａＯ－ＳｉＯ２－Ｎａ２Ｏ－ＣａＦ２－Ａｌ２Ｏ３－ＭｇＯ渣系,通过测定熔渣的粘度、凝固温度和粘性活化能,研究了连铸保护渣的粘性特征与碱度、ＮａＣＯ３含量、ＣａＦ２含量、Ａｌ２Ｏ３含量和ＭｇＯ含量之间的关系。利用连铸保护渣的粘性特征与化学成分之间的回归方程,可以设计满足一定粘性特征的连铸保护渣。     

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.     

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...     

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。     

Influences of Na2O and K2O Additions on Electrical Conductivity of CaO-MgO-Al2O3-SiO2 Melts

Metallurgical and Materials Transactions B - The present study investigated the influences of Na2O and K2O additions on electrical conductivity of blast furnace type CaO-MgO-Al2O3-SiO2 melts by the...     

Influences of Al2O3/CaO and Na2O/CaO Ratios on Viscosities of CaO-Al2O3-SiO2-Na2O Melts

The influences of Al₂O₃/CaO and Na₂O/CaO ratios on viscosities of CaO-Al₂O₃-SiO₂-Na₂O melts are investigated by the rotating cylinder method in this study. It is indicated from the experimental results that viscosity first increases and then decreases as gradually increasing Na₂O/CaO ratio. As increasing Na₂O/CaO ratio while keeping the contents of Al₂O₃ and SiO₂ constant, the transformation of bridging oxygen (from being bonded with Al³⁺ ion charge compensated by Ca²⁺ ion to that compensated by Na⁺ ion, for the higher priority of Na⁺ ion relative to Ca²⁺ ion) increases the viscosity, whereas the transformation of non-bridging oxygen decreases the viscosity. These two factors lead to the appearance of viscosity maximum. The viscosity model proposed in our previous papers could well describe the viscosity variation tendency.     

Heterogeneous equilibria in the Au-CN-H2O and Ag-CN-H2O systems

The equilibrium relationships in the systems Au-CN-H₂O and Ag-CN-H₂O have been investigated with the aid of the DIAGRAM computer program and thermodynamic data taken from the literature. On the basis of stability diagrams such as Eh-pH, log[Me]-pH, and log[CN]-pH, a discussion is pre-sented of the behavior of gold and silver in cyanide solutions. It is shown that gold and silver have similar behaviors in cyanide media; both metals exhibit wide solubility domains with di-cyanide complexes predominating. Solid AgCN is stable only in solutions of low pH and high silver/cyanide ratio; the species Ag(CN)₃ ^2- and Ag(CN) ₄ ³ form only in concentrated cyanide solutions.     

Inspired O2 and N2O concentrations in essentially closed circuits

By simulation of the FRC (functional residual capacity), washin of N2O was conceptually separated from uptake at the alveolar-capillary membrane. Data collected by mass spectrometry and pneumotachography during a period of 2 years showed a near-constant body uptake of N2O which makes clinical application of closed circuit N2O--O2 anesthesia simple and safe. The data failed to confirm accelerated washin by higher concentrations of N2O ("the concentration effect"), although there was a concentrating effect according to the law of mass action.     

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.     

二元碱度和Al_2O_3对CaO-SiO_2-FeO-Fe_2O_3-P_2O_5-Al_2O_3-MgO-MnO钢渣中磷酸盐富集的影响

以八元CaO-SiO_2-FeO-Fe_2O_3-P_2O_5-Al_2O_3-MgO-MnO钢渣体系为研究对象,结合热力学计算和实验检测,分析了二元碱度B和Al_2O_3含量对八元钢渣系中磷酸盐富集行为的影响。结果表明:钢渣二元碱度和Al_2O_3含量直接影响钢渣中f-C2S的生成量,进而影响磷酸盐富集相nC_2S-C_3P内P_2O_5的含量。随着二元碱度从1.3提高至2.5,磷酸盐富集率增大,磷酸盐富集相nC2S-C3P中的P_2O_5含量呈现先迅速增大(B从1.3至1.7),然后逐渐减小(B从1.8至2.5)的趋势。当二元碱度和Al_2O_3质量分数分别控制在1.7和12%时,即当满足四元碱度R为1.23时,此八元钢渣体系有较好的磷酸盐富集效果,磷酸盐富集相nC_2S-C_3P内的P_2O_5的质量分数可以达到24.23%。     

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。