基于修正的(NBO/T)比值的黏度模型

针对传统的(NBO/T)比值计算方法在熔渣黏度预报上的不足,研究氧化物对熔渣聚合度的影响规律,修正了(NBO/T)比值的计算方法,计算结果反映了黏度随(NBO/T)比值变化的基本趋势.提出了一个基于修正的(NBO/T)比值的黏度预报模型.利用该模型预报了CaO-SiO2-Al2O3三元系、高炉渣CaO-SiO2-MgO-Al2O3四元系和CaO-SiO2-Al2O3-RO(R2O)体系的黏度值,预报效果比传统的Urbain模型和修改后的Iida模型要好.该模型能有效预报CaO-SiO2-MgO-Al2O3-R2O(K2O或Na2O)体系黏度值.     

高硅氧化铜矿还原熔炼渣黏度研究及Iida模型应用

针对刚果（金）某高硅、低铁氧化铜矿还原熔炼过程渣铜分离困难、铜收得率低等问题,研究了配加不同CaO和FeO含量对还原熔炼渣黏度的影响规律,并在此基础上优化了Iida黏度预测模型,为实现CaO-SiO2-MgO-Al2O3-FeO渣系黏度的精准控制提供支撑。结果表明,该熔炼渣黏度随CaO和FeO含量的增加而逐渐下降。调控终渣碱度大于0.5、FeO含量大于3%,可有效改善熔炼渣黏度。利用优化后的Iida黏度预报模型可在较大成分与温度范围内进行本体系熔渣黏度的预测,预报相对误差在10%以内。     

Al_2O_3和MgO对含铬渣黏度及结构影响的研究

为使铬铁冶炼过程中的渣系具有良好流动性同时让渣金分离顺利进行,研究Al_2O_3和MgO对含铬渣黏度的影响具有重要的理论价值。应用拉曼光谱法从微观结构方面研究了Al_2O_3和MgO对CaO-SiO2-MgO-Al_2O_3-Cr_2O_3渣系黏度的影响。结果表明:在牛顿流体状态下,含铬渣的黏度随着渣中Cr_2O_3及Al_2O_3含量的增加而增大,随着MgO含量的增加而降低。结合拉曼光谱的分析结果,随着Al_2O_3含量的增加,高聚合度单元Q_(Si)~2和Q_(Si)~3的含量随之增大,而低聚合度单元Q_(Si)~1和Q0Si的含量随之降低,渣系中每个参与形成网络结构的硅原子所含非桥氧数量(NBO/Si)降低,因此熔渣聚合度增大。而随着MgO含量的增加,熔渣结构发生高聚合度单元Q_(Si)~3向低聚合度单元Q_(Si)~1和Q0Si的转变,NBO/Si值增大,渣系黏度变化与熔渣聚合度变化趋势保持一致。因此,通过分析渣系组元含量变化对渣系聚合度的影响可直观体现黏度变化趋势。     

基于共存理论的含铬渣黏度预测模型

熔渣黏度对冶金过程尤为重要。为预测含铬渣黏度,基于炉渣离子与分子共存理论,结合课题组测试得到的系列含铬渣黏度数据,建立含铬渣黏度与温度和结构单元之间的预测模型。模型计算的黏度值与实测值吻合较好,通过模型,有助于在较大的适用范围内预测含铬渣黏度。模型能够计算含铬渣黏度的大小,考察黏度受温度和组分影响的变化趋势。结果表明,随着温度、碱度和MgO质量分数的增加,黏度降低。随着Cr2O3和Al2O3质量分数的增加,黏度升高。相比于高温情况下,低温下组分对黏度的影响程度更大。     

CaO-SiO2-Al2O3-Fe2O3渣系脱磷行为

利用Factsage软件计算了Al2O3含量对CaO-SiO2-Al2O3-Fe2O3四元渣系熔点和黏度的影响,并通过实验研究了在1 400℃时,CaO-SiO2-Al2O3-Fe2O3四元渣系对高磷铁水脱磷行为的影响.结果表明:渣中Al2O3的质量分数在3％～6％之间时,随着A12O3含量的增加,渣系的熔化温度迅速降低,进一步增加渣中的A12O3含量,渣系的熔化温度逐渐增加;Al2O3对CaO-SiO2-Al2O3-Fe2O3渣系的黏度影响不大;渣中Al2O3的质量分数在3％～6％之间变化时,渣系脱磷能力变化不是很大,脱磷率维持在91％左右,进一步增加渣系中A12O3的量,脱磷率逐渐下降;Al2O3对脱磷率产生影响可能是其改变了炉渣中液相所占比例,进而影响磷从铁水中向液相渣的传质过程.     

CaO-SiO2-FeO-Cr2O3-MgO-MnO渣系物相组成的热力学计算

摘要：在含铬铁水转炉冶炼过程中,Cr很容易被氧化成Cr2O3进入渣中,并与渣中其他成分反应生成高熔点含铬尖晶石。采用FactSage热力学软件计算了CaO-SiO2-FeO-Cr2O3-MgO-MnO转炉渣系在冶炼温度1300～1700℃下的物相组成,研究了Cr2O3、FeO和碱度对炉渣中尖晶石相含量的影响规律。研究结果表明,温度和渣系成分都会影响炉渣的物相组成。渣系中含有Cr2O3时,物相中均含有MgCr2O4、FeCr2O4和MgFe2O4尖晶石相,尖晶石相的总含量随着Cr2O3和碱度的增加而增加,随着炉温的升高而减少。温度为1300～1500℃时,炉渣中尖晶石含量随着FeO的增加而增加;温度为1500～1700℃时,尖晶石含量随着FeO的增加而略有减少。在温度小于1500℃的转炉冶炼前中期,炉渣物相组成中尖晶石相所占比例较大,易造成化渣不良或者炉渣粘稠,影响转炉冶炼工艺的顺行。     

Fe-Cr-C金属与CaO-SiO2-MgO-(Al2O3)-CrOx渣反应平衡时渣中Cr含量预测

摘要：冶炼不锈钢或高温还原法处理不锈钢工业典型固废时,渣金反应终点渣中残Cr含量 (w(Cr)slag)的高低是评价还原操作经济性以及残渣是否无害的关键参数。借助热化学软件FactSage,计算了Fe-Cr-C熔体中［Cr］的活度、反应体系的氧势及CaO-SiO2-MgO-(Al2O3)-CrOx-O2熔渣的等活度图,并构建了残Cr预测模型,综合讨论了平衡态时金属成分(［Cr］、［C］含量)、熔渣成分(二元碱度、MgO、Al2O3)以及温度对渣中残Cr含量的影响,得到了不同条件下渣中残Cr含量的极限值。实验室试验结果与模型预测结果基本一致,验证了模型的可靠性。     

基于IMCT理论的CaO-SiO2-MgO-Al2O3-Na2O渣系的脱硫热力学模型

 为了精确表征含Na2O渣系的脱硫能力，改善脱硫效果，基于熔渣离子与分子共存理论（IMCT）建立了CaO-SiO2-MgO-Al2O3-Na2O渣系结构单元的作用浓度计算模型和1 753 K时该渣系的脱硫热力学模型。并对渣系的总硫分配比及各自硫分配比的影响因素进行了讨论分析。理论结果表明，除LS， MgS外，随着Al2O3质量分数的增加，该渣系的脱硫能力明显下降，而MgO和Na2O质量分数的增加，对提高渣系的脱硫能力具有明显的促进作用。此外，少量的Na2O即可表现出很强的脱硫效果，这为含有Na2O的冶金二次资源在铁水脱硫过程中的应用以及铁水脱硫渣系的优化提供了必要的理论依据。     

CaO-SiO2-Al2O3-MgO-FeO渣系FeO活度的计算模型

利用熔渣结构共存理论建立了CaO-SiO2-Al2O3-MgO-FeO渣系FeO活度的计算模型,并分析了1400℃时炉渣碱度、MgO和FeO含量对该渣系FeO活度的影响规律。结果表明：当CaO-SiO2-Al2O3-MgO-FeO渣系三元碱度为1.3,Al2O3含量为12wt%,FeO含量为2wt%条件下,随MgO含量的增加,炉渣FeO活度增大;当二元碱度为1.1,Al2O3含量为12wt%,MgO含量为10wt%时,FeO活度随随渣中FeO含量的增加呈线性增加;当渣中Al2O3、MgO和FeO含量分别为12wt%、10wt%和2wt%固定不变时,随着二元碱度的提高,炉渣FeO活度迅速增加。计算得到的上述规律和实测规律一致,说明了本模型用于分析FeO活度的正确性。     

碱度对CaO-SiO2-Al2O3系熔渣微观结构的影响

为了明确精炼渣冶金功能的微观本质,本文模拟精炼渣的化学组成,采用拉曼光谱测定并解析了CaO-SiO2-Al2 O3系实验渣的熔体结构.结果表明,熔渣中Si4+以[SiO4]-四面体结构形式存在,随着碱度的升高,Q1Si和Q2Si含量减少,Q0Si含量增加;Al3+以[AlO4]-四面体和[AlO6]-八面体结构形式存在...     

含Ce2O3锰铁脱磷渣系熔化性质及黏度

 采用立式管式炉制备得到含Ce2O3锰铁脱磷渣系,分别利用HCT-2综合热分析仪和RTW-10型熔体物性仪对渣系的熔化性质和黏度进行测试分析。研究表明,碱度为1.05时,渣系的开始熔化温度和完全熔化温度随[w(Ce2O3)]的增加而升高,其最大值分别为1 121.6和1 282.1 ℃;碱度为0.97时,渣系的开始熔化温度和完全熔化温度随[w(Ce2O3)]的增加出现先降低后升高的趋势,当[w(Ce2O3)]为3时出现最小值,分别为1 008.8和1 148.5 ℃。渣系的黏度值随[w(Ce2O3)]的增加先降低后升高,当[w(Ce2O3)]为3%时,黏度值最小。在碱度为1.05和0.97的脱磷渣系中,黏度最小值分别为0.378和0.308 Pa·s。因此,[w(Ce2O3)]为3%时的锰铁脱磷渣系具有良好的熔化及流动特性。     

覆铜板废边角料熔炼渣黏度研究

覆铜板废边角料是一种具有明显"高硼低铁"特征的电子废料,为获得适合覆铜板废边角料回收工艺的黏度特性,用分析纯化学试剂配制合成覆铜板废边角料熔炼渣,采用RTW-10型熔体综合物性测定仪测定熔炼渣的黏度,并探索了FeO含量(wFeO)、Fe3O4含量(wFe3O4)、Al2O3含量(wAl2O3)、B2O3含量(wB2O3)及钙硅比(mCaO/mSiO2)等炉渣组成对黏度的影响规律。结果表明,熔炼渣黏度随熔炼温度T、wFeO、wB2O3和mCaO/mSiO2增大而减小;随wFe3O4或wAl2O3增大而增大;在工业生产熔炼温度下(1 100~1 200℃),黏度在0.1~0.5Pa·s之间波动,流动性较好,能满足冶炼要求。     

Viscosity of Industrial Blast Furnace Slag in Indian Scenario

Twenty-five numbers of blast furnace slag samples are collected from different operational Indian blast furnaces. The viscosities of these slag samples are estimated using various models developed by several researchers for the purpose. Subsequently, viscosities of some selected slag samples are measured using a high temperature viscometer to choose the best possible model that can be used in the present investigation. On the basis of the results, a comparison is made between the various models bringing about the shortcomings of these mathematical models. It is observed that the estimated viscosities by Iida model are best fitted with the viscosities of slags measured by high temperature viscometer and hence, the viscosity data obtained by Iida model are analyzed at length to ascertain the compositional dependence of slag viscosity. It is observed that the industrial blast furnace slag viscosity is greatly influenced by its CaO/SiO₂ ratio, MgO and Al₂O₃ contents.     

Viscosities Behavior of CaO-SiO2-MgO-Al2O3 Slag With Low Mass Ratio of CaO to SiO2 and Wide Range of Al2O3 Content

 The present paper is aimed at recycling of coal ash and blast furnace slag to produce mineral wool. Considering the mineralogical constitutions of coal ash and blast furnace slag, the primary quaternary slag compositions of CaO-SiO2-MgO-Al2O3 with basicity (mass ratio of CaO to SiO2) ranging from 05 to 09 and alumina ranging from 5% to 20% were investigated through a rotating cylinder method. The experimental results indicated that the viscosities decreased with increasing basicity above the liquidus temperature, and increased with increasing alumina content, and the maximum values were reached and as the alumina content was 20%, followed by the decrease with further increasing alumina content due to its amphoteric behavior. The amphoteric behavior of Al2O3 also performed in the relationship between viscosity and non-bridging oxygen per tetrahedrally-coordinated atom (NBO/T), and the viscosities decreased with increasing the NBO/T except the slag with a basicity 05 and Al2O3 20% which have a low NBO/T value and a low viscosity than others.-     

Viscosity of Fluoride‐Free Mold Fluxes Containing B2O3 and TiO2

Viscosities of B₂O₃ and TiO₂‐bearing fluoride‐free mold fluxes have been measured by the rotating cylinder method in this work. Effects of different B₂O₃, TiO₂ content, and basicities on the viscosity characteristics have been examined. Viscosity of fluoride‐free mold fluxes containing B₂O₃ and TiO₂ was found to decrease with the increase of B₂O₃, TiO₂ content, and basicity. The values of apparent activation energy for viscous flow of slags decrease with additions of B₂O₃ and TiO₂ and the increase of basicity. Two parameters A and B in Riboud model were re‐evaluated based on the present experimental data, and the modified Riboud model was used to estimate the viscosity of fluoride‐free slag system investigated in present work. The viscosity values obtained by the experimental measurement were in good agreement with those calculated by the modified Riboud model.     

Experimental Investigation on Viscosity of CaO-MgO(-Al2 O3)-SiO2 Slags and Solid-liquid Mixtures

The viscosities for the selected CaO-MgO-SiO_2 and CaO-MgO-Al_2O_3-SiO_2 slags were measured by rotating cylinder method in a wide temperature range from 1 608 K to 1 823 K.The effects of temperature,slag basicity and Al_2 O_3 content were studied.The results indicated that the viscosity decreased with increasing the slag basicity at the same temperature.And the viscosities of the slag initially increased linearly with increasing Al_2O_3 content in the slags and then decreased as the Al_2O_3 content in the slags continued to increase.Al_2O_3 addition has a more significant effect on the viscosity than slag basicity in the selected slags.Based on the experimental data and the fraction of solid phases calculated by the thermodynamic software,the effect of solid phases on slag viscosity was evaluated.The results indicated that the relationship between the relative viscosity and the volume fraction of solid phases estimated from the slag composition can be reasonable by allowing the inverse maximum fraction of solid particles to vary.     

Viscosity and Structure Changes of CaO-SiO2-Al2 O3-CaF2 Melts with Substituting Al2 O3 for SiO2

During the smelting process of the high Al steels,the reaction between SiO_2 in molten slag and dissolved aluminum in liquid steel always takes place.This aluminathermic reduction reaction will lead to the substitution of 1mol SiO_2 for 2/3mol Al_2O_3.Therefore,the investigations about the influence of the ratio of Al_2O_3 to SiO_2on viscosity and structure changes of mould flux during this process are very necessary.The viscosity variation of CaO-SiO_2-Al_2O_3-CaFv2 melts was studied by changing compositions considering the aluminathermic reduction reaction.It was found that viscosity increased monotonously with gradually increasing the substitution extent.According to the Raman analysis,the substitution of Al_2O_3 for SiO_2 leads to the decrease of non-bridging oxygen but the increase of bridging oxygen.Therefore,degree of polymerization and viscosity increase as the substitution extent increases.By comparing the measured viscosities with the model calculated values,it was found that both the recently developed Zhang′s model and Roboud model could describe the viscosity variation behavior of CaO-SiO_2-Al_2O_3-CaF_2 melts very well.     

Immobilization of Chromium in Slags using MgO and Al2O3

Chromium containing slags from stainless steelmaking may be leached by acidic environments, therefore they should be treated before being stockpiled or land filled. In this work, synthetic slags were prepared and the effect of CaO/SiO₂, Cr₂O₃, MgO and Al₂O₃ contents on the stability of the mineralogical species formed was analysed. The morphology and composition of the slags were determined by XRD and SEM‐EDS, whilst their chemical stability was evaluated by leaching with an aqueous acetic acid solution. It was found that CaCr₂O₄ and CaCrO₄ are present in slags prepared with neither MgO nor Al₂O₃. The Al₂O₃‐based slags mainly produced Ca₂Al₂SiO₇ and the Cr(VI)‐containing oxide complex Ca₄Al₆CrO₁₆, whilst MgO‐based slags produced Mg Cr₂O₄ as main mineralogical species. Additionally, Eh‐pH diagrams for the Ca‐Cr‐H₂O and Mg‐Cr‐H₂O systems at 25°C were constructed. The results showed that the lowest chromium concentration levels in the leaching liquors corresponded to MgO‐based slags owing to the stable binding of chromium in spinel with MgO. It was also observed in the Al₂O₃‐based slags that when increasing the slag basicity from 1 to 2, the leachability of the slags was notably increased.