CaO-SiO2-Al2O3-MgO-Na2O-CrOx炉渣中铬氧化物间的氧化还原平衡

采用化学平衡法研究了 16 73和 1773K下CaO SiO2 Al2 O3 MgO Na2 O CrOx 渣系中铬氧化物间的氧化还原平衡。在实验条件下 ,渣中铬氧化物主要以Cr2 + 形式存在。lg[x(Cr2 + ) /x(Cr3 + ) ]与 -lgp(O2 )呈线性关系 ,斜率在 1/ 4左右 ,与理论分析相符。x(Cr2 + ) /x(Cr3 + )随碱度的增加而减小 ,随氧分压的降低、温度升高和铬氧化物总量的增加而增大     

中间包保护渣中碳和V2O5含量对钢液氮含量的影响

为了研究中间包保护渣中碳和V2O5含量对钢液氮含量的影响,选用CaO—SiO2—Al2O2系碱性渣作为基础渣系进行实验。通过对实验结果分析可知,渣中的碳和V2O5含量对钢液脱氮都有一定的影响,但效果不一样。     

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。     

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.     

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。     

融熔Cu-S,Fe-S/CaO-SiO_2-Al_2O_3体系界面脱硫反应动力学的阻抗谱分析

本工作用频率响应分析法测量了融熔 Ｃｕ－Ｓ, Ｆｅ－Ｓ／ ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３体系的交流阻抗,得到了阻抗谱用 Ｒａｎｄｌｅｓ等效电路,将所得的阻抗谱用非线性最小二乘法拟合,得到了Ｃｕ－Ｓ,Ｆｅ－Ｓ／ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３体系界面脱硫反应动力学参数：溶液电阻Ｒｅ,界面反应电荷传递电阻 Ｒｃｔ,双电层电容Ｃｄ及界面脱硫反应的速率常数ｋｆ等．     

高磷铁矿石熔融还原中铁浴和熔渣间磷分配行为的研究

通过对铁浴与CaO-SiO2-MgO-Al2O3-FeO-2.3％P2O5熔融还原渣系间磷分配行为的热力学实验研究,考察了高磷铁矿石熔融还原中温度、炉渣成分、CO2/CO气氛对磷在铁浴和熔渣间分配行为的影响.实验结果表明,渣金间磷分配行为的氧势为(％FeO)控制的炉渣氧势,CO2/CO控制的气氛氧势则要高于该氧势,但是气氛氧势与该分配行为的氧势仍存在相关性.在光学碱度为0.65～0.69的范围内,a3/2O2-/γPO43-随着光学碱度的上升而升高;在高光学碱度条件下,温度对于渣中磷酸根活度系数的影响不大.     

液态“渣—金属”化学平衡求取渣系组元活度的探讨

简单介绍以液态“渣－金属”化学平衡法求取渣系组元活度的方法及步骤,并以此测定了ＣａＯ－ＳｉＯ２－Ａｌ２Ｏ３,ＣａＯ－ＳｉｉＯ２－ＭｇＯ和ＣａＯ－Ｂ２Ｏ３等渣系中ＣａＯ的活度。结果表明,正确选择金属溶剂,正确配料－－包括炼制好金属料需要的有关合金和适合渣料需要的预备渣,以及正确选择测试温度和平衡所需时间,是实验成功的关键。     

液态“渣-金属”化学平衡法求取渣系组元活度的探讨

简单介绍以液态“渣-金属”化学平衡法求取渣系组元活度的方法及步骤，并以此测定了CaO—SiO2-Al2O3,CaO-SiO2-MgO和CaO－B2O3等渣系中CaO的活度结果表明．正确选择金属溶剂，正确配料──包括炼制好金属料需要的有关合金和适合渣料需要的预备渣，以及正确选择测试温度和平衡所需时间，是实验成功的关键.     

DESULFURIZATION OF CAST IRON BY ELECTROLYZING SLAG

<正> 一、前言 在铸造上应用土高炉生产的高硫生铁有着很多困难。首先是它能够促使铸铁铸态成为硬而脆的白口组织,不能加工和应用;其次它使铸铁铸造性能恶化,铸造废品率大大增加。为了解决土铁在铸造上应用的问题,通常采取二种办法: (一)利用高硫:当铸铁的S/Mn>1时,将铸态所得的白口胚件,经过短时间的退火,使自由渗碳体分解石墨化,而得到球状石墨的所谓球墨可锻铸铁; (二)去硫:使铸铁中含硫量降到0.10％左右,以符合一般铸铁含硫量的标准。 第一种方法应视为一种不得已的措施,因为它并没有能够彻底的解决问题。首先它并没有能解决高硫铸铁的铸造性能不良的问题;其次采用退火的办法增加了燃料、工时及     

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．     

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.     

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。     

灰铸铁电渣重熔过程石墨球化现象的研究

实验证明,采用高Ｓｉ含量铸铁自耗电极和含稀土氧化物的ＣａＦ２基熔渣,在直流反极性电渣重熔条件下,可制得球墨铸铁,铸铁中石墨球化现象是铁水经电化学变质处理的结果,熔渣中Ｍｇ１Ｃｅ阳离子在渣－金界面阴极区被还原进入铁水熔池,起到球化剂的作用,提高阳极区自耗电极中的Ｓｉ含量,可以抑制渣中Ｆｅ阳离子的形成,有助于上述电池化学还原反应的进行,这对建立新的冶金工艺技术有一定意义。     

Corrosion resistance of MgO–C refractory to smelting reduction slag containing titania

Abstract

Interactions between smelting reduction slags containing titania (0·2-20 wt-%TiO₂) and MgO-C refractories have been investigated by stationary immersion and rotary immersion at temperatures of 1773-1923 K. The relationship between the concentration of TiO₂ in the slag and the corrosion rate of the refractories, the effects of slag basicity (CaO/SiO₂), and the effect of the temperature of the molten bath on the corrosion rate were examined. Increasing the TiO₂ concentration in the slag caused an increase in the corrosion rate of the MgO-C refractories. The corrosion rate also increased when the temperature was increased. Increasing the basicity of the acid slag decreased the corrosion rate, but this effect was not evident when the basicity of slag exceeded 1·0. The corrosion mechanism of MgO-C refractories in smelting reduction melts containing titania involves the oxidation of graphitic carbon by TiO₂ and the formation of a deterioration layer containing Ti and TiC, together with the reaction of matrix MgO with slag to form MgAl₂O₄, MgCaSiO₄, and MgSiO₃.     

含Ti高炉渣冷却及析晶过程中电导率的变化

用交流阻抗方法测量了含Ｔｉ高炉渣及ＣａＯ—ＳｉＯ２－Ａｌ２Ｏ３－ＭｇＯ五元合成渣在１６５３－１７３３Ｋ温度范围内的电导率,检测到了熔渣冷却过程Ｃａ－Ｔｉ矿相（ＣａＴｉＯ３）的初晶温度是１６９３Ｋ．由于渣中ＣａＴｉＯ３的析出,渣的碱度减小,并导致两性氧化物Ａｌ２Ｏ３和ＴｉＯ２呈碱性并发生离解：ＴｉＯ２＝Ｔｉ(４＋)２Ｏ(２－),Ａｌ２Ｏ３＝２Ａｌ(３＋)３Ｏ(２－)．通过电导率的测量确定了该离解反应达到平衡的时间．并计算出Ａｌ２Ｏ３和ＴｉＯ２离解反应的速率常数之和及ＣａＴｉＯ３生成反应的速率常数在１７０３－１７３３Ｋ温度范围内将电导率数据按Ａｒｒｈｅｎｉｕｓ形式进行了回归．     

Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content

Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（ Ⅱ）. The relationship between Fe（ Ⅱ ） content and oxidizing time at different temperatures was obtained by chemical analysis. Microstructure of slag was observed by metallographic microscope and SEM. Phases compositions were ascertained by EDXS and XRD. Grain size and crystallizing quantity of magnetite（Fe3O4 ） were determined by image analyzer. The oxidizing kinetic equations were deduced. Confirmed by graphical construction method, Fe（ Ⅱ ） oxidizing reaction in CaO-FeOx-SiO2 slag system is of first order, and the reaction apparent energy Eo is 296. 67 kJ/mol in the pure oxygen and 340. 30 kJ/mol in air. The enrichment and crystal growth mechanism of magnetite（Fe3O4 ） phases were investigated. In oxidizing process, content of fayalite declines, while that of magnetite（Fe3O4 ） increases, and iron resources enrich into magnetite（Fe3O4 ） phase. All these provide a theoretical base for compressive utilizing of those slags.     

THE DESULPHURIZATION OF MOLTEN SLAGS IN THE GASEOUS PHASE DURING TOP-BLOWN WITH AIR

利用空气顶吹研究熔渣的气态脫硫动力学,着重研究了熔渣∑FeO含量、j值[j=N_(Fe_2O_3)/(N_(Fe_2O_3)+N_(FeO))]、以及碱度对气态脫硫速度的影响.对气态脫硫反应的机理及反应速度的限制性环节作了分析和讨论.最后,对金属直接的气态脫硫、炉渣的气态脫硫和炉渣脫硫本身的矛盾、以及气态脫碗在转炉炼钢工艺上的应用问题进行了简要的讨论.     

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。     

Distribution behavior of vanadium and phosphorus between slag and molten steel

The correlation of the equilibrium behaviors of phosphorus and vanadium between slag and low carbon molten steel in inert atmosphere was investigated with respect to the experimental variables of slag basicity, the (P₂O₅) and (V₂O₅) content, and the reaction temperature. The distribution ratios of phosphorus and vanadium increased with an increase in the slag basicity. The logarithms of the vanadium distribution ratio were greater by a factor of about two than those of phosphorus in the range of low slag basicity, but the difference diminished with an increase in the slag basicity. The logarithms of the vanadium distribution ratio increased linearly with an increase in the (P₂O₅) and (V₂O₅) content in the slag, while those of phosphorus remained nearly constant. The logarithms of the phosphorus and vanadium distribution ratio decreased with an increase in temperature, and the dependence on temperature was greater for the phosphorus than for the vanadium. For both the maximization of the vanadium yield and the minimization of the rephosphorization of molten steel in the steelmaking process, the ratio of N_(V2O5)/N_(P2O5), the slag basicity, the ratio of f_[P]/f_[V], and the temperature should be maximized, and the (FeO) content in the slag should be minimized.