熔渣发泡幅度的理论模型

讨论熔渣发泡现象的实质,建立泡沫渣发泡幅度的理论模型,并结合实验数据讨论了模型参数。结果表明;发泡幅度随熔渣粘度增大及表面张力的减小而增大,渣中悬浮的固相粒子对泡沫稳定有着特殊贡献。     

谈谈冶金中的泡沫渣

<正> 泡沫渣通常是指在一定的高温冶金条件下,熔渣中形成大量气泡,并在其内部滞留聚集,使高温液态炉渣体积成倍增长,且能稳定维持较长时间时熔渣所具有的一种特殊形态。泡沫渣在平炉、转炉、电弧炉以及熔融还原等许多冶金过程中都广泛存在。根据不同冶金过程的具体要求,泡沫渣在有些情况下要抑     

含FeO熔渣的起泡过程及起泡参数间关系分析

对ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３－ＦｅＯ熔渣在石墨还原过程中的起泡行为的分析表明，熔渣的起泡率受渣中气体的产生速度及熔渣的起泡指数影响；熔渣的起泡指数随渣中气泡直径的增大而减小；随熔渣碱度的减小，泡沫渣的平均寿命延长，泡末化愈稳定。     

锰熔融还原渣的泡沫性研究

用X射线动态显像技术在1300～1450℃的范围内研究了CaO－SiO2－MnO渣系的泡沫性，采用单位时间单位气量所产生的泡沫渣量作为泡沫指数描述熔渣的泡沫性。测定了CaF2、FeO、MgO、S及MnO本身对该渣系泡沫性的影响。研究表明渣的泡沫稳定性随着熔渣粘度的增大和表面张力的减小而增大。     

含钛高炉渣碳热还原时熔渣泡沫化原因分析

以含钛高炉渣碳化过程的热力学计算为理论依据,从熔渣性质、碳粒作用、气源等方面对泡沫渣成因进行分析,并提出了控制泡沫渣的重要方式,即改变熔渣性质和避免CO气体集中释放。     

Mgo-B_2O_3-SiO_2-CaO-Al_2O_3体系富硼渣表面张力的计算EI北大核心CSCD

基于熔渣结构的离子与分子共存理论和Butler方程建立了MgO-B_2O_3-SiO_2-CaO-Al_2O_3体系表面张力计算模型,计算了该体系及其子体系表面张力值,考察了熔渣表面张力随熔渣组分的变化规律,以期为富硼渣调控和综合利用提供参考。结果表明:本模型计算的熔渣表面张力值与实验值吻合较好,模型平均相对误差为9.03%。含B_2O_3的二元体系中,B_2O_3组元显著降低熔渣表面张力,纯氧化物表面张力值与形成氧化物阳离子的静电势及氧化物中离子键的分数有关。含B_2O_3的多元体系中,熔渣表面张力随着B_2O_3含量的增加而显著降低,但随着MgO和SiO_2质量比、CaO含量和Al_2O_3含量的增加而逐渐增大,且CaO和Al_2O_3含量对含B_2O_3渣表面张力的影响基本相当。     

Mgo-B_2O_3-SiO_2-CaO-Al_2O_3体系富硼渣表面张力的计算

基于熔渣结构的离子与分子共存理论和Butler方程建立了MgO-B_2O_3-SiO_2-CaO-Al_2O_3体系表面张力计算模型,计算了该体系及其子体系表面张力值,考察了熔渣表面张力随熔渣组分的变化规律,以期为富硼渣调控和综合利用提供参考。结果表明:本模型计算的熔渣表面张力值与实验值吻合较好,模型平均相对误差为9.03%。含B_2O_3的二元体系中,B_2O_3组元显著降低熔渣表面张力,纯氧化物表面张力值与形成氧化物阳离子的静电势及氧化物中离子键的分数有关。含B_2O_3的多元体系中,熔渣表面张力随着B_2O_3含量的增加而显著降低,但随着MgO和SiO_2质量比、CaO含量和Al_2O_3含量的增加而逐渐增大,且CaO和Al_2O_3含量对含B_2O_3渣表面张力的影响基本相当。     

CaO-Al_2O_3-TiO_2熔渣表面张力计算模型

基于熔渣结构离子与分子共存理论和Butler方程,建立了CaO-Al2O3-TiO2熔渣表面张力计算模型。本模型利用纯组元的表面张力和摩尔体积以及熔渣中各组元表面相和体相中作用浓度(活度)可以计算出CaO-Al2O3-TiO2熔渣表面张力随熔渣成分、温度的变化规律。将计算得到的表面张力值与文献实测值进行对比,计算结果与文献实测值吻合较好。并进一步绘制了CaO-Al2O3-TiO2熔渣等表面张力线,考察了炉渣成分对表面张力的影响,以期为含TiO2渣系控制提供理论参考。     

MgO-B_2O_3-SiO_2三元体系熔渣表面张力计算

基于熔渣结构离子与分子共存理论和Butler方程建立了MgO-B_2O_3-SiO_2系表面张力计算模型,计算了该体系及其二元子体系的表面张力值,考察了熔渣表面张力随熔渣组分的变化规律,以期为含B2O3渣系控制提供参考。结果表明:本模型计算的熔渣表面张力值与文献实验值吻合较好,模型平均相对误差为9.73%。Mg O-B_2O_3和B_2O_3-SiO_2二元体系中,熔渣表面张力随着B_2O_3含量的增加而降低,纯氧化物表面张力值与形成氧化物的阳离子静电势及氧化物中离子键分数有关。MgO-B_2O_3-SiO_2三元系中,熔渣表面张力随着B_2O_3和SiO_2含量的增加而减小,且B_2O_3对表面张力的影响更加显著;随着Mg O含量的增加,熔渣表面张力逐渐增大。     

CaF_2-CaO-Al_2O_3-MgO-SiO_2渣系表面张力计算模型

基于熔渣结构离子与分子共存理论和Butler方程,建立了CaF2-CaO-Al2O3-MgOSiO2熔渣表面张力计算模型。本模型利用纯组元的表面张力和摩尔体积以及熔渣中各组元表面相和体相中作用浓度(活度)可以计算出CaF2-CaO-Al2O3-MgO-SiO2熔渣表面张力随熔渣成分、温度的变化规律。将计算得到的表面张力值与文献实测值进行对比,计算结果与文献实测值吻合很好。进一步考察了炉渣成分对表面张力的影响,以期为电渣重熔法精炼铜铬合金过程渣系的控制提供理论参考。     

Surface Structure of Nonoxidizing Slags Containing Sulphur

Application of surface tension measurements has been made to molten silicates in order to determine the effect of sulphur upon the surface tensions of synthetic blast furnace slags. In melts with the same molar ratios of Al2O3 + SiO2 to the basic oxides BaO, CaO, and MgO, the surface tensions increase in the order of oxides listed. Sulphur lowers the surface tensions of the basic BaO, basic CaO, acid BaO, acid CaO, and acid MgO slags in that order; and the concentration of excess sulphur at the slag surface increases in this same order of slags. The rate and amount of desulphurization of iron by these slags is favored by a low excess surface sulphur in the slag.     

活化焙烧-酸浸法富集中低品位富钛料

采用还原磨选法制得的富钛料TiO2品位低,不适合直接作生产氯化法钛白和海绵钛的原料.热力学分析表明,采取添加Na2CO3进行焙烧处理后,可破坏富钛料中主要矿物组分黑钛石(Me3O5型固溶体,Me=Ti、Fe、Mg、Mn等)的固溶体结构,使固溶于其中的杂质元素铁和镁等转变为易溶于稀盐酸的物质.结果表明,用稀盐酸浸出活化富钛料可使浸出产物TiO2品位提高到90%以上,比直接用稀盐酸浸取未经活化的富钛料浸出产物TiO2的品位提高了近10%.     

ACTIVITY OF TiO_2 IN MOLTEN BLAST FURNACE SLAG

Activity of TiO_2 in the molten blast furnace slag containing TiO_2 has been examinedat 1500℃ by means of “molten slag-Sn” chemical equilibrium method,using metallicSn as flux and graphite as deoxidizer,together with phase diagram caIculation.In thepentary slag system CaO-MgO-SiO_2-TiO_2-Al_2O_3,a_(TiO_2)=0.01—0.05 or 0.02—0.10 withpure liquid or solid TiO_2 as standard state,respectively.The activity and activitycoefficient of TiO_2 in relation to concentration of TiO_2 have been discussed.     

退火温度及TiO_2结构对羟基磷灰石的沉积诱导作用

采用阳极氧化法在钛金属表面制备TiO2薄膜,将表面改性的钛金属在过饱和钙化溶液中浸泡,在其表面沉积羟基磷灰石,研究了退火处理温度对TiO2薄膜晶型转变的影响以及TiO2的晶型结构对羟基磷灰石的诱导沉积作用。研究表明,300℃退火处理,TiO2薄膜为板钛矿相,500℃退火处理转变为锐钛矿相,高于500℃退火处理,锐钛矿相开始向金红石相转变。其中锐钛矿相的TiO2对羟基磷灰石的沉积具有最好诱导作用,沉积物分布均匀,板钛矿相对羟基磷灰石的诱导作用最差,所形成的沉积层是由片状的羟基磷灰石围成的多孔结构。     

Reduction mechanism of stainless steelmaking dust and carbon pellets

1 INTRODUCTIONThe smelting temperature generally reaches1 600 ℃or higher in stainless steel making opera-tion. Under this condition,approxi mately 1 % 2 %(mass fraction) of the scrap charged into the fur-nace is converted to dust[1]as by-product of steel-making process .It has been assigned as a hazard-ous waste and banned from landfills by variousgovernment regulatory agencies because it containsa lot of heavy metals such as zinc ,lead,cadmium,chromium and nickel , which will be leached …     

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%。     

RESEARCH ON PLASMA SMELTING OF ILMENITE

The process of Luda ilmenite smelting by plasma furnace has been studied by means ofself-designed plasma torch. The prereduced Luda ilmenite was melted satisfactorily in plasmafurnace to produce Ti enriched slag containing 90-98% TiO_2.     

INTERFACIAL TENSION BETWEEN SLAG AND COPPER MATTE

The interfacial tension between FeO-CaO-SiO_2-MgO system slag and Cu-Fe-S systemmatte was determinated by the X-ray radiograph sessile drop method.The effects ofFeO/SiO_2 ratio in the slag,contents of CaO,FeO,ZnO and CaF_2 in the slag on interracialtension and the relation of inter facial tension with the grade of matte and temperature havebeen studied.The floatation coefficient and film coefficient of slag-matte system has beencalculated and the mechanism of the transition of iron and oxygen from slag to matte has alsobeen discussed.     

Burning products of TA15 titanium alloy by friction oxygen concentration method

The microstructural characteristics, elemental distribution law and microscopic formation mechanism of the burning products of TA15 titanium alloy were investigated by friction oxygen concentration method, associated with in situ observation, X-ray diffraction(XRD),scanning electron microscopy(SEM) and energy-dispersive spectroscopy(EDS) analyses, providing the thoughts to improve fireproof property. The results show that, when the friction contact pressure(p_(fric)) is 0.20 MPa and oxygen concentration of premixed air flow(c_0) is 60 vol%, TA15 titanium alloy produces violent sparks and presents dazzling white light during combustion. The generated products after burning are mainly TiO_2 and small amount of Al_2O_3 oxides. Four distinct zones form from the combustion surface to the alloy matrix, and they are in the sequence of combustion zone, fusion zone, heat-affected zone and transition zone. Further, combustion zone is composed of TiO_2 and A1203 compounds, containing obvious cracks. In the fusion zone, discontinuous oxygenrich Al-based solid solution forms, and the elemental distribution has strong volatility. In the heat-affected zone,there are abundant of Ti-based solid solution and small amount of Al-and Mo-based solid solution. Transition zone is made of lamellar structure. Two technical approaches are given to prevent oxygen diffusion inside the reaction zone and reaction-affected zone. On the one hand,the content of Al is designed as the upper limit of alloy composition; on the other hand, fireproof coatings are deposited on the surface of the alloy.     

MIGRATION OF Ti BETWEEN SLAG AND MOLTEN IRON

本文得到Ti在含TiO_2熔渣与熔铁之间的迁移规律如下:该过程受渣中Ti离子扩散的控制,其表观反应级数为准零级,表观活化能为258kJ/mol.讨论了渣中TiO_2含量、碱度和温度对Ti迁移量和迁移速度的影响.发现了炉渣碱度对Ti迁移的两重性影响:当渣中TiO_2含量较高时,提高碱度将抑制Ti的还原;而在TiO_2含量较低时,提高碱度则促进Ti的还原.并根据热力学分析,认为按[Si]/[Ti](wt-％)的大小可划分出Si促进或抑制Ti还原的区域.