含氧化钛高炉型渣表面张力的测定

攀钢大高炉冶炼中发现含氧化钛高于25%的渣,出现泡沫渣现象,并溢出渣罐妨碍生产。生成泡沫渣有两个条件:一是在熔渣内部有足够大量而分散的气体源;二是熔渣表面张力低、表观粘度高,使气泡稳定且有足够的机械强度、不易破坏或合并。已证实在含氧化钛高炉渣中悬浮着碳化钛、氮化钛及碳氮化钛微粒,这些微粒提高了熔渣的表观粘度,是使气泡稳定的重要因素之一。有人用气泡最大压力法,测定含氧化钛高炉型渣的表面张力,指出氧化钛是表面活性物质。但     

Effects of mineral loading methods on carbon solution reaction of coal-derived carbon material

1 Introduction The addition of the same oxide into carbon material with different methods has been discussed in previous studies[1?6]. The results showed that different mineral loading method could lead to different effects on carbon solution reaction of…     

THE APPLICATION OF THE LAW OF MASS ACTION IN COMBINATION WITH THE COEXISTENCE THEORY OF SLAG STRUCTURE TO THE MULTICOMPONENT SLAG SYSTEMS

1. IDtroduction to the Coexistence Theory of Slag StructureA lot of paper have already been published in the field for application of the law ofmass action in combination with the coexistence theory of slag structure to the binaryand ternary slag systems[1--'1. In this paper3 some examples about application of both tothe multicomponent slag systems are given. First of all, an introduction to the coexistencetheory of slag structure is presented, then followed by some examples about its applic…     

保护渣对铝钛系夹杂物溶解的吸收规律

以CaO-SiO₂-Al₂O₃-Na₂O-CaF₂-MgO为基础渣系,采用旋转动力学方法研究了不同碱度、BaO质量分数(0~15%)、B₂O₃质量分数(0~15%)对连铸保护渣吸收Al₂O₃或TiO₂速率的影响以及吸收前后矿相变化。结果表明,保护渣吸收TiO₂的速率要远大于吸收Al₂O₃的速率;添加BaO或B₂O₃后均能提高保护渣吸收Al₂O₃和TiO₂的能力;保护渣主要物相为钙镁黄长石(2CaO·MgO·2SiO₂)、钙铝黄长石(2CaO·Al₂O₃·2SiO₂)、枪晶石(3CaO·2SiO₂·CaF₂)及玻璃相(Na₂O·Al₂O₃·SiO₂);添加BaO后,钙镁黄长石转变为重硅酸钡钙镁(2CaO·MgO·2SiO₂·BaO),并抑制黄长石和枪晶石晶体长大;当添加B₂O₃的质量分数不低于10%,保护渣形成的物相为玻璃相。试验条件下,不同碱度的保护渣和添加B₂O₃的保护渣中TiO₂仍以TiO₂形式存在,而在添加BaO的保护渣中,TiO₂形成钙钛矿。     

Reactive wetting phenomena of MgO-C refractories in contact with CaO-SiO2 slag

Wetting phenomena between MgO C and CaO SiO2 slags were investigated by varying carbon content.A sessile drop technique was adopted to study the wetting phenomena in conjunction with a high speed camera for the observation of intrinsic wetting phenomena.The results show that the high content of SiO2 and the presence of Al2O3 in slags enhance the diffusion of Mg2+,leading to the promotion of reactive wetting.The carbon in MgO C refractory impedes the penetration of slags by repelling the slag and slowing the diffusion of Mg2+.This accounts for the non-wetting behavior of the slag on MgO C refractory with 17% (mass fraction) carbon similar to that of graphite.     

Viscosities of Fe_nO-MgO-SiO_2 and Fe_nO-MgO-CaO-SiO_2 slags

1　INTRODUCTIONTheviscosityofliquidslagsisanimportantphysicalproperty .Innickelflashsmeltingprocesses ,slagscontainmainlyironoxidesandsilicainadditiontoMgO ,CaO ,Cr2 O3andAl2 O3aswellasvaluemet alsandotherimpurities .Manyinvestigationsontheviscosityofironsilicatemeltwerealreadyreport ed[14 ] .Butonlyfewstudiesarereportedontheslagsinthecompositionrangeoccurringinnickelmattesmelting.Thismaymainlybeattributedtoexperi mentaldifficultiesinviscositymeasurementsforthehighmeltingtemperatureofi…     

The Kinetics of Boron Transfer in Slag Refining of Silicon

Slag refining is one of the few metallurgical methods for efficient removal of boron from silicon. In industrial slag refining for production of silicon for photovoltaic applications, the relationship between the slag composition and the mass transfer rate of boron from metal to slag is of great importance. The kinetics of boron removal from liquid silicon during slag refining has been investigated in the present work by means of several small-scale experimental series at temperatures between 1,600°C and 1,650°C. Slag and metal, in batch weights of 30?g, were heated together in a graphite crucible placed in a resistance-heated tube furnace. The slags were produced from powdered SiO₂, CaO, and MgO. The oxides applied were of high purity. Experiments were carried out at slag-to-metal ratios of 1 or 2, where the silicon initially contained approximately 250?ppm boron. Metal?Cslag mass transfer coefficients were calculated based on chemical analyses of the silicon and ranged from 1.7???m/s for slag consisting of equal amounts of SiO₂ and CaO by weight, to 4.3???m/s for a 40%?C40%?C20% SiO₂-CaO-MgO slag.     

熔渣的溶氢能力与熔敷金属的扩散氢

分别改变碱性焊条熔渣中CaO和Mgo与气保护药芯焊丝熔渣中Al2O3和MgO组元的相对含量,研究其对熔敷金属扩散氢的影响.结果表明,碱性焊条熔渣中,用同等质量MgO取代CaO导致熔敷金属扩散氢大幅度提高;药芯焊丝焊接熔渣中,脱氧产物若不是以Al2O3为主而是以MgO为主,熔敷金属扩散氢则大幅度提高.分析认为,熔渣成分的变化导致其溶氢能力的变化是这一结果的主要因素,即Ca2 离子导致熔渣含氧量的提高及氢在Al2O3中具有较高的溶解度等提高了熔渣的溶氢能力.     

Basicity for blast furnace-type slag containing B_2O_3 and high MgO

1　INTRODUCTIONBasicityofaslagisoneofoldandimportanttop icsin physicalchemistry .Thereisnostandardfor mulationforbasicitycalculation .Ingeneral,basicityofaslagisexpressedbythemassratioofCaOtoSiO2ortotalalkalineoxidestototalacidicoxides .Accord ingtotheiontheoryofslag ,basicityofaslagshouldbeexpressedbytheactivityofoxygenion ,whichisdifficulttodetermine .Frombasicity principle pro posedbyWagnerandotherinvestigators[15] ,basicityofaslagisproportionaltoitssulfidecapacity .Rela tionshipbet…     

B2O3—MgO—SiO2—Al2O3—CaO系渣组成对溶体物性的影响

用柱体旋转法测定了Ｂ_２Ｏ_３—ＭｇＯ—ＳｉＯ_２—Ａｌ２Ｏ_３—ＣａＯ系富硼镁渣的粘度及熔化性温度，用双柱联称法测定熔渣的密度及表面张力．实验结果表明：富硼镁渣的粘度及熔化性温度随渣中Ｂ_２Ｏ_３含量的增加而降低；当Ｂ_２Ｏ_３含量一定时，随渣中ＭｇＯ量及渣碱度的增加而增大．熔体的密度及表面张力随ＭｇＯ量增加或ＳｉＯ_２量减少而增大，分别为（２．５±０．５）ｔ·ｍ~（－３）和０．４－０．６Ｎ·ｍ~（－１）．     

690镍基合金真空感应熔炼脱硫

采用真空感应熔炼,精选原材料,分别利用预制MgO坩埚和预制CaO坩埚,其中在MgO坩埚中加入稀土镧,在CaO坩埚中加入金属铝,采用这两种不同的工艺分别对690镍基焊接材料进行脱硫.结果表明,在低硫含量范围内(S≤0.003%,质量分数),前一种工艺起不到脱硫作用,而后一种工艺却大幅度脱硫,铸锭硫含量降低到0.0004%...     

Chromium distribution between liquid iron and molten basic slags

An equilibrium study was made of the distribution of chromium and oxygen between liquid iron, containing less than 1 pct Cr, and simple slags of the CaO(MgO)-SiO₂-FeO-Cr₂O₃ type in the temperature range 1526° to 1734°C The effects of slag oxidation, temperature, and basicity were observed.     

BaO对铝酸盐熔渣微观结构和宏观性能的影响

为探究非反应性组分BaO对铝酸盐熔渣微观结构稳定性及宏观性能的影响机制,综合半球点熔点仪、旋转黏度计、四探针法电导率测定仪、红外光谱分析仪,研究了BaO对铝酸盐熔渣(w(CaO)/w(Al₂O₃)=1.3)熔化温度、黏度、电导率和结构的影响规律。结果表明,随着BaO质量分数增加,BaO会简化铝酸盐熔渣微观网络结构,使铝酸盐熔渣结构聚合度降低;由于试验组分范围内熔渣熔化温度变化很小,可说明过热度对熔渣黏度影响不大,即熔渣黏度降低主要受聚合度降低影响;由于Ba2+浓度增加及熔渣网络结构聚合度降低,熔渣电导率增加。此外,随着BaO含量的增加,黏度-温度曲线上转折温度递减,说明BaO提高了熔渣低温段的玻璃特性,因此,BaO有利于铝酸盐基保护渣润滑特性的改善。     

Effect of MnO to hydrogen dissolution in CaF2–CaO–SiO2 based welding type fluxes

Abstract

The effect of MnO on the hydrogen solubility in the CaF₂–CaO–SiO₂ based welding flux system at 1823 K has been studied. At an acidic slag composition of CaO/SiO₂ molar ratio or basicity of 0·8 and below, MnO addition decreased the hydrogen solubility. At an intermediate slag composition of CaO/SiO₂ molar ratios of 1·1 and 1·3, the hydrogen solubility as a function of MnO additions resulted in a parabolic behaviour showing a minimum and then increasing with higher MnO content. MnO was found to behave as a basic oxide, which decreases the hydrogen solubility when the incorporation hydroxyl mechanism is dominant for an acidic slag and increases the hydrogen solubility when the free hydroxyl mechanism is dominant for a basic slag. This change in the dominant hydrogen dissolution mechanism was also apparent from the hydrogen solubility results at various CaO/SiO₂ molar ratios and fixed MnO contents. A higher hydrogen solubility in the slag is likely to lower the diffusible hydrogen content in the weld metal, and optimum MnO additions were suggested depending upon the basicity of the slag. Fourier transformed infrared analysis of as quenched slags showed that MnO depolymerised the slag network structure and correlated well with the effect on the hydrogen solubility in slags.     

FCB法三丝单面埋弧自动焊焊接冶金反应分析

借助XRF、XRD、EPMA等测试手段,对FCB法三丝单面埋弧自动焊表面焊剂NSH-55E的焊接冶金反应进行了初步分析。结果表明,熔敷金属中存在少量夹渣物,主要由SiO2、FeO、CaO及CaSiO3构成;焊剂和熔渣中存在的主量物质为MgO、SiO2、CaO、Al2O3、CaF2、TiO2、Na2O、MnO、Fe2O3,另外因焊接高温化学冶金作用,熔渣中新生成了CaO·MgO·2SiO2、CaO·Al2O3·2SiO2物相;熔渣中MnO、TiO2的含量明显高于焊剂,这与焊剂中加入了一定量的锰铁和钛铁作为合金剂和脱氧剂有关。     

Li2O对CaO基钢包渣系脱磷能力影响的热力学研究

渣金平衡实验表明Li2 O替代CaO基钢包渣系中等量CaO使渣系磷酸盐容量Cp提高。在此基础上进行钢液脱磷的工艺性实验 ,研究了Li2 O含量、渣系碱度及氧化性对渣系脱磷能力的影响 ,并给出了控制转炉钢液在钢包中回磷及钢包渣脱磷的渣系。     

渣中BaO和TiO2在真空下对钢液氮含量的影响

为了研究钢包顶渣中BaO和TiO2在真空下对钢液中氮含量的影响,选用caO-SiO2-Al2O3碱性渣作为基础渣系.实验结果表明,真空下,渣系中的BaO和TiO2对钢液氮含量有较强的影响作用;向熔渣中同时添加BaO和TiO2配成的渣系对钢液脱氮作用强于它们单独加入渣中的渣系对钢液脱氮的作用.     

RE2O3-MgO-SiO2（RE=La,Nd,Sm,Gd和Y）熔体表面张力的计算模型（英文）

基于熔体组元离子半径和Butler方程,建立RE2O3-MgO-SiO2(RE=La,Nd,Sm,Gd和Y)熔体表面张力热力学计算模型。本模型利用纯组元的表面张力和摩尔体积以及熔体中各组元阳离子和阴离子半径可以获得E2O3-MgO-SiO2熔体表面张力随熔渣成分和温度的变化规律。计算1873 K La2O3-MgO-SiO2熔体等表面张力线并研究熔体成分对表面张力的影响。1873 K的纯组元La2O3,Gd2O3,Nd2O3和Y2O3的表面张力通过本模型计算分别为686、677、664和541 m N/m。除了Y2O3外,纯稀土氧化物的表面张力随其阳离子磁场强度增加而呈线性减小,而Y2O3的表面张力相对减小更多。表面张力的计算结果与文献数据一致,1873 K本模型平均偏差为1.05%。     

含MO（MO=FeO,NiO）的低碱度CaO-MgO-Al2O3-SiO2熔渣电导率（英文）

作为有色冶金渣中有价金属回收基础,利用电化学交流阻抗谱法,测定低碱度MO(MO=FeO,NiO)-CaOMgO-Al2O3-SiO2五元熔渣体系的电导率。结果表明:随着熔渣体系温度的升高和MO浓度的增大,熔渣电导率增大。在1573～1773K下,(CaO+MgO)与(SiO2+Al2O3)质量比为0.47,当MO浓度小于12%时,熔渣电导率为1.4～14.4S/m。随着熔渣中MO浓度的增大,熔渣电导率增大的幅度增加。当熔渣中FeO和NiO浓度小于8%时,两种熔渣的电导率相差不大;当浓度达到12%时,含FeO的熔渣电导率明显大于含NiO的熔渣电导率。随着MO浓度的增加,电导活化能降低。     

Na2O对含MgO铝酸钙炉渣相变规律和氧化铝浸出性能的影响（英文）

采用向铝酸钙炉渣体系中添加Na2O的方法,降低或消除铝酸钙炉渣中MgO的负作用,并分析其影响机理。结果表明:当MgO含量为3%时,Na2O的添加量由0增加至4%后,炉渣的氧化铝浸出率由68.73%提高到80.86%。对含4%Na2O的样品进行XRD分析,发现四元化合物C20A13M3S3已消失。添加Na2O不能完全消除MgO对炉渣浸出性能的负作用。XRD和EDS分析结果表明,Na2O会进入12CaO·7Al2O3的晶格并促进其形成。