熔渣规则溶液模型的发展及其在冶金物理化学中应用的综述(二)

系统介绍了熔渣规则溶液模型在冶金物理化学领域的应用，如计算硫、磷、氧、锰在渣-钢间的平衡分配比，组元活度，炉渣中Fe3+/Fe2+平衡比率及氢氧容量。     

Thermodynamic Calculations for the Dephosphorization of Silicon Using Molten Slag

The dephosphorization of metallurgical-grade Si using molten slags has recently attracted much attention. In the current study, the thermodynamic assessment of an Si-P system was first carried out, and then the dephosphorization reaction equilibria between molten Si and CaO-based slags were calculated using the thermodynamic databases for Si alloy and slags. The thermodynamic calculations show that dephosphorization of Si under oxidizing conditions (in the form of phosphate) merely happens, and the dephosphorization under reducing conditions (in the form of phosphide) can cause the significant dissolution of Ca in molten Si.     

KINETICS OF REDUCTION IRON OXIDE IN CaO-SiO_2-Al_2O_3-Fe_tO SLAGS WITH CARBON SATURATED IN MOLTEN IRON

1.IntroductionItisimportanttoinvestigatethekineticsofreductionofironoxideinslagswithcarbonsaturatedinmoltenironforunderstandingboththeslag-metalreactioninthehearthofblastfurnaceandthefinalreductionbehavioursofprereductionironorepelletscontainingcarboninironbathreactor.Theprevious.......h..sll--7]focusedtheirattentionsmainlyonthereductionrateofpureironoxideortheredlltionrateofironoxideinsimpleslags.Thoseresultsarenotconsistentwiththatoftilerealsituation.Throughanalyzinggascompositionattheoutlet…     

PRECIPITATION SELECTIVITY AND GROWTH OF PEROVSKITE PHASE FROM TITANIUM BEARING BLAST FURNACE SLAG

The effects of transformation of slag composition and additive agents on the morphology, the precipitation behavior, the crystal growth, and the volume fraction (VF) of perovskite (CaO·¤TiO_2) crystal in the Ti-bearing blast furnace slags were investigated. As the morphology of perovskite is dispersed in molten slags, the crystal growth mechanism of the melting of fine dendrites and the coarsening of large grains exist throughout the solidification of molten slags. With the increase of CaO and Fe_2O_3 content, VF of perovskite obviously increases. However, high basicity leads to the viscosity of slag, which results in the reduction of the average equivalent diameter (AED). The experimental results showed that the presence of the additives CaF_2 and MnO efficiently decreased the viscosity of the slags, and obviously improved the morphology of perovskite and promoted its growth.     

PREDICTION OF THERMODYNAMICS DATA OF TERNARV AND QUAfERNARY MOLTEN ALLOYS WITH NRTL EQUATION

1.DerivationofNRTLEquationNRTL(Non--RandomTwoLiquids)equationwasdevelopedbyRenonandp.....it.11]in1968.BeingsimilartoWilson'sequation,itisalsoasemiexpiricalequationbasedontheconceptoflocalcomposite.Itisusefulforrepresentingequilibriumdataforawidevarietyofliquidmixtures.Theprecisionisoftenrelativelyhigh.Especially,itiscompatiblewithphaseinstability,andcanbeusedforpredictingtheexcessGibbsenergyfrombinarydataalone.InNRTLequation,therelationbetweenthelocalmolefractionsisgivenbywherexijisth…     

铝合金熔体中氢溶解度的计算模型

基于Sieverts定律和多元合金组元活度系数计算模型,建立了一个计算氢在多元合金熔体中的溶解度的计算模型,该模型只需要氢在纯金属熔体中的溶解度参数,为预测多元合金熔体中氢含量提供了有效的途径.以此计算了氢在多种铝合金熔体中的溶解度随温度变化的情况,计算结果与实验值吻合较好.     

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.     

熔渣无污染短路电化学还原分析

在可控氧流冶金理念指导下发展了熔渣无污染短路电化学还原新方法。分析了以氧离子导体作隔离膜时从氧化物熔渣中直接提取金属的电化学还原原理。利用电池等效电路,比较了熔渣在短路、开路条件下电化学还原时氧电流的特点,讨论了熔渣还原时影响氧电流的因素。结果表明:外电路短路、降低电路中总电阻、选用更强的还原剂或采用阴极合金化等措施可以增大氧离子电流,提高熔渣电化学还原速度。实验利用碳饱和铁液作还原剂,组成如下两种电池:石墨棒|[O]Fe C饱和|ZrO2(MgO)|FeO(slag)|铁棒;石墨棒|[O]Fe C饱和|ZrO2(MgO)|FeO(slag) Cu(l)||钼丝,从CaO-SiO2-Al2O3-FeO系熔渣中分别得到了纯铁和无碳铁合金。     

多元Al-Cu系合金凝固过程中显微偏析的计算模拟

以物质守恒方程,液固界面平衡方程为基础,提出一个反映多元合金系中组元间相互作用的凝固模型,并从应用的角度出发,对该模型进行了合理的简化,利用这个模拟对合金元素在多元Ａｌ－Ｃｕ系合金凝固过程中的行为进行计算模拟,所得的情况与实验结果相一致,表明这个多元系凝固模型可以为多元Ａｌ－Ｃｕ系合金化设计作出有效的预测。     

硼渣中硼组分选择性析出行为

变温过程硼渣中含硼组析出表现晶态与非晶态两种形态。形成含硼玻璃相对分离困难，以遂安石（２ＭｇＯ．Ｂ２Ｏ３）晶相析出时硼提取率明显提高，通过调整渣的的化学组成，控制热处理温度和有效添加剂等因素可以使渣中硼组分以遂安石为主相存在，实现选择性析出，对析出相量微形貌进行了ＳＥＭ动态原位跟踪，再配合分形理论与计算机模拟的研究方法，证实渣中硼组分析出过程涉及分相和析晶两个步骤，分相符合不稳分解机理，２ＭｇＯ．     

修正的准化学溶液模型及其在计算冶金炉渣组元活度中的应用

简要介绍准化学溶液模型和Pelton等提出的修正的准化学溶液模型，并总结了采用修正的准化学溶液模型计算SiO2为唯一酸性组元的二元、三元冶金渣系组元活度的方法．     

基于最小Gibbs自由能原理的CaO-SiO2炉渣和Si-Ca金属两相体系平衡热力学模型

基于封闭平衡体系Gibbs自由能最小原理对精炼Si液中杂质Ca的炉渣金属体系建立热力学模型,由该热力学模型得到Si液中Ca的摩尔分数xCa与CaO-SiO2二元渣系CaO的摩尔分数xCaO的关系和文献报道的实验结果吻合良好,即0.3相似文献   

Estimation models for molten slag and alloy viscosities

Viscosities of molten metals and slags play vital roles in many high-temperature phenomena that are important for advancing process control and product quality in molten-metal processing and casting. Because measuring viscosities of high-temperature melts is expensive, the need exists for reliable viscosity estimation methods based on the temperature and composition of the melt. This paper reviews some available models for alloys and slags, and examples are shown for melts of interest to both ferrous and non-ferrous processing     

SELF-INTERACTION COEFFICIENTS OF Ca AND Mg IN DILUTE Sn-BASED SOLUTION

The interaction coefficients of Ca.Ti and Mg in the dilute Sn-based solution have been de-termined at 1500℃.Experimental measurements were taken by equilibrating the slag-alloysystems with metallic Sn as flux and graphite as reducing agent under Ar atmosphere mixedwith different portion of CO.It was found that a considerable error may produce if thecoefficients of ε_(Ca)~(Ca),ε_(Mg)~(Mg)and ε_(Ti)~(Ti)in the molten Sn were neglected when the activities of thecomponents CaO,MgO and TiO_2 in the slags were estimated by this method.     

熔渣规则溶液模型及其在冶金物化中的应用（一）

Ｌｕｍｓｄｅｎ于１９６１年提出的熔渣规则溶液模型近年得到逐渐发展和完善，作者系统综述了熔渣规则溶液模型及熔渣规则溶液模型中的两个关键参数，阳离子间互作用能和规则溶液与真实溶液活度转化因子的确定方法，简单介绍了阳离子间互作用能与二元复合氧化物生成热、阳离子半径的关系。     

Rotation-cylinder method for fabrication of SiC particle reinforced magnesium composites

A new molten metal mixing process, RCM (Rotation-Cylinder Method) for incorporating reinforcement particles into molten magnesium, has been developed for manufacturing SiC particle reinforced magnesium composites in an ambient atmosphere. The RCM can be characterized by the U-shaped laminar melt surface with the Rankine vortex, which significantly reduces particle agglomeration and entrapped slags, such that composites of improved microstructure and properties can be manufactured successfully in conjunction with the subsequent fabrication processes. The RCM can incorporate SiC particles (5 urn size and larger) into molten magnesium with particle volume fractions of up to 20 vol.%. In this paper, the development background, the characteristic vortical motions, the optimum manufacturing conditions and the in-process wetting procedures of the RCM are described.     

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…     

短路还原法提取铁的研究

采用氧离子导体氧化锆管与还原剂碳、含有电活性物质FeO的熔渣组成电化学体系,利用原电池短路方法从氧化物熔渣中电化学还原得到了无碳金属．实验电池组成为：石墨,[O]Fe—C（aaturated）｜ZrO2（MgO）｜Cu（1）＋（FeO）（alag）,钼丝．利用电化学分析仪,通过测定外电路电流研究了渣中FeO含量、温度以及外电路电阻对熔渣中FeO电化学还原的影响．结果表明：在实验条件下,温度越高,渣中FeO含量越高,外电路电阻越小,熔渣电化学还原就越快．实际终还原率达95％以上．提出了可控氧流冶金中的一种还原方法,发展了可控氧流冶金理论．     

Carbothermic reduction of chromite fluxed with aluminum spent potlining

Aluminum spent potlining (SPL) was employed as both the fluxing agent and a source of carbonaceous reductant for the carbothermic reduction of chromite, aiming to allow effective separation of alloy from the slag component. The experimental results show that the carbonaceous component of the SPL is more reactive towards chromite reduction compared to graphite. The formation of refractory spinel (MgAl₂O₄) on chromite particles hinders further reduction and alloy growth. The slag-making components of the SPL (e.g. nepheline and NaF) form molten slags at low temperatures (～1300 °C) and partly dissolve the refractory spinel as well as the chromite. Destruction of the spinel layer with enhanced mass transfer greatly improves the alloy growth, which can be further promoted by reduction at a higher temperature (e.g. 1500 °C). Ferrochrome alloy particles grow large enough at 1500 °C in the presence of SPL, allowing effective separation from the slag component using elutriation separation.     

ACTIVITY OF CaO IN LIQUID CaO-SiO_2 AND CaO-Al_2O_3-SiO_2 SLAGS

利用石灰的加碳还原反应,设计了一个新的研究方法,以直接测定液态高炉型渣中CaO的活度.这一方法的成功,依靠溶剂金属的正确选择以降低熔液中钙的化学位,而使金属钙量提高到可以用化学分析测定的水平.我们估计钙在锡稀溶液中的活度系数很小,可能符合于我们的要求,因此研究了下列反应:CaO+C(石墨)=Ca(锡)+CO(气).以测定液态CaO-SiO_2和CaO-Al_2O_3-SiO_2渣中CaO的活度,在上式中符号下波纹线表示溶于渣中的组分,直线表示溶子金属中的组分,下同.对于CaO-Si0_2系,应用Gibbs-Duhem关系从CaO活度值算出了SiO_2的活度值,并根据一个统计力学模型讨论了活度曲线的形状.从CaO-Al_2O_3-SiO_2系的研究结果,可知在所研究的整个碱度范围內,渣中存在10%Al_2O_3都使CaO的活度增加;当Al_2O_3为20%时,则对CaO活度的影响视碱度不同而异.对Al_2O_3的这种行为,根据炉渣的离子结构理论提出了解释.