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．     

用铬传感器测定碳饱和铁液中Cr的活度

用ZrO2（MgO）固体电解质，以CasiO3＋Cr2O3作为辅助电极，组成铬传感探头：Mo|Cr，Cr2O3|ZrO2（MgO）|CaSiO3，Cr2O3|[Cr]Fe|Mo－ZrO2于1753K测定了碳饱和铁液中Cr的活度该探头响应快，约2—3s即可得到稳定的电动势值，测定误差为主±1～2mVCr的活度与Cr的浓度之间符合理论关系     

Pure metal extraction from molten oxide slag by short-circuit galvanic cell

The oxygen-ion-permeable membrane galvanic short-circuit method has been developed, in which pure metal was directly extracted from the molten oxide slag, and no external voltage is applied. The galvanic cell employed in the experiment was as follows: graphite rod|[O]_(Fe C saturation)[ZrO_2(MgO)|(FeO)_(slag))|Fe rod. The reduction current in the galvanic cell consisted of an external short-circuit current and an interior short-circuit current in the oxygen-ion-permeable membrane. The real-time variation of external circuit reduction ratio of the molten slag could be obtained from the curve of the external circuit current to the time.     

CaCl2熔盐中直接电化学还原制备铽-镝-铁合金机制

CaCl2熔盐为电解质,石墨棒作辅助电极、铂片作参比电极,以定组成Tb2O3、Dy2O3、Fe2O3(1:1:2)均匀混合氧化物粉体制成工作电极,利用循环伏安法和计时电流法对电化学还原制备铽-镝-铁合金的过程进行研究,并以石墨棒为阳极,混合氧化物烧结片为阴极,采用恒电位电解法对电化学测试结果进行检验并利用XRD分析电解产物的组成。结果表明,CaCl2熔盐中电化学还原可以制备出铽-镝-铁合金;混合氧化物电化学还原制备铽镝铁合金是不可逆过程,合金生成按照Fe、DyFe5、TbFe3、DyFe2和TbFe2的先后顺序5步完成;电化学还原过程是在Fe|Fe2O3|CaCl2、Tb-Dy-Fe|Tb2O3-Dy2O3|CaCl2两个三相界线上先后进行。     

高铬型钒钛磁铁精矿煤基直接还原-磁选分离过程中钒和铬的行为（英文）

高铬型钒钛磁铁精矿的煤基直接还原过程中·V2O3和FeO·Cr2O3的还原行为对其高效综合利用产生决定性的影响。采用XRD、SEM及EDS等手段对直接还原产物进行分析,分别考察碳铁摩尔比和温度对煤基直接还原-磁选分离过程中钒和铬行为的影响。结果表明:当碳铁摩尔比(n(C)/n(Fe))从0.8增大到1.4时,V和Cr的回收率分别从10.0%和9.6%增大到45.3%和74.3%。当n(C)/n(Fe)为0.8时,在1100~1250°C的温度范围内,V和Cr的回收率始终低于10.0%;而当n(C)/n(Fe)为1.2时,随着温度从1100°C升高到1250°C,V和Cr的回收率分别从17.8%和33.8%增大到42.4%和76.0%。当n(C)/n(Fe)低于0.8时,由于含碳还原剂的量不足,绝大多数FeO·V2O3和FeO·Cr2O3不能被还原成碳化物,且温度(1100~1250°C)对其还原行为的影响甚微。在更高的n(C)/n(Fe)下,由于含碳还原剂的量充足,FeO·V2O3和FeO·Cr2O3的还原率大幅提高,且更高的温度能有效地促进碳化物的生成。新生成的碳化物溶解在γ(FCC)相中,并在磁选过程中与金属铁同时回收。     

1673K下SiO_2-CaO-MgO-Al_2O_3熔渣中Ni~(2+)的电化学行为

利用Mg O部分稳定的Zr O2固体电解质管集成构建Pt,O2(air)|Zr O2作参比电极的可控氧流电解池,采用循环伏安、方波伏安、计时电位、恒电位电解等电化学测试技术研究了1673 K高温下Si O2-Ca O-Mg O-Al2O3熔渣中Ni2+的电化学行为.结果表明,O2-在熔渣中的扩散和在Zr O2固体电解质内的电迁移不是熔渣中电活性物质还原的限制性环节,在本实验条件下利用构建的可控氧流电解池研究熔渣中Ni2+的电化学行为是可行的.熔渣中Ni2+在Ir电极上还原到Ni是受扩散控制的一步还原的可逆过程,利用循环伏安和计时电位测试技术所得数据计算得出了含有3%Ni O的熔渣中Ni2+的扩散系数分别为(3.50±0.18)×10-6和(2.80±0.22)×10-6cm2/s,与相关文献结果基本吻合.     

利用电化学方法测定高温银液中氧的扩散系数

采用圆柱体状氧化锆基固体电解质原电池:(+)Pt|air|ZrO_2(MgO)[O]_(Ag(l))|Ir(-),利用恒电压法测定了1473-1773 K银液中氧的扩散系数.通过外加恒电压后测定的电池外电路总电流,获得随时间变化的穿过固体电解质的氧离子电流,进而计算得到银液中氧的扩散系数.在假定符合Arrhenius公式的基础上,实验结果经最小二乘法处理确定的在1473—1773 K扩散系数与温度的关系为:D_O=(1.11±0.04)×10~(-3)exp((-25573±1718)/RT).实验测得的银液中氧的扩散系数值与基于前人低温测定结果外推到本实验温度下的值比较接近.利用该公式计算得到1773 K下银液中氧的扩散系数D_O=(1.96±0.28)×10~(-4)cm~2/s.     

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。     

非接触式熔融还原法制备金属镍

采用非接触式熔融还原法,以氧化镁部分稳定的氧化锆管作为氧离子渗透膜,将阴极与阳极分隔开,分批向阴极一侧(熔渣)加入氧化亚镍,在阳极(碳饱和铁水)补充碳还原剂,进行连续制备无碳金属镍的实验研究。结果表明:金属镍沉积在液态阴极上面,以金属单质形式存在,可以通过机械或熔分方法来分离;升高反应温度和增大金属氧化物加入量有利于还原反应的进行,按加入1gNiO外电路电流降至100mA通过电量计算,反应温度从1743K升高到1773K,加入1g和2gNiO还原时间分别缩短54min和18min,而两个温度下NiO加入量增加后,还原时间缩短近一半。     

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.     

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…     

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。     

Rate of FeO Reduction from a CaO-SiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Slag by Carbon-Saturated Iron

Reaction rates have been measured for the reduction of FeO from a lime-silica-alumina slag over carbon-saturated iron in graphite crucibles. The initial FeO concentrations were under 5 pet in a base slag composition of 46 to 47 pet CaO, 38 to 39 pet SiO₂, 15 to 16 pet A1₂O₈.The reaction rate was found to be proportional to about the second power of the analyzed iron content of the slag. Two rate constants were obtained for simultaneous reactions at the slag-metal and slag-graphite interfaces. Values for these constants at 1430°C (2606°F) were k₁ = 0.00058 g FeO per (min) (sq cm) (pet FeO)² at the metal and k₂ = 0.00012 (same dimensions) at the graphite. The temperature coefficient was not measured independently for the two reactions, but the net effect of a 140°C rise in temperature was small.Iron droplets rose to the surface of the slag with gas bubbles and collected in a ring adjacent to the crucible wall in amount equal to or greater than the weight of iron calculated from FeO reduction, in those runs with both slag and metal. When only slag was present in the crucible, the iron beads were more evenly distributed over the entire crucible wall and were smaller in size and total amount.It is not possible to deduce a reaction mechanism to interpret the observations on the basis of these experiments alone, but several alternatives have been discussed in terms of intermediate reaction products, dissociation of FeO in the slag, diffusion, nucleation of gas or metal, and surface phenomena leading to reaction through iron films on rising bubbles of CO in the slag.The rate of reduction of FeO in the absence of sulphur is qualitatively consistent with the part that this reaction is believed to play in the desulphurization of iron by slags under similar experimental conditions.     

涡流贫化法回收铜渣中的金、银、铜

采用熔融铜渣为原料,经过涡流贫化过程,回收铜渣中的金、银、铜,贫化渣进一步升温还原得到含铜铁水,最终可制备成耐磨铸铁。结果表明,通过涡流贫化,铜渣中的Fe_3O_4被还原为FeO,然后FeO与SiO_2结合,生成Fe_2SiO_4。经过涡流贫化后,金、银、铜的回收率分别达到了99.44%、93.97%和93.14%。贫化渣中Fe_3O_4和铜的含量分别为1.53%和0.61%(质量分数)。贫化渣涡流还原后得到的含铜铁水制备的耐磨铸铁成分满足高铬耐磨铸铁国标要求。     

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.     

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…     

P2O5对熔渣界面氧迁移反应的影响及机理

利用同位素交换法测定了熔渣表面CO2与氧化铁熔渣之间氧迁移反应的速度常数,并基于电化学反应机制,分析了添加P2O5对该过程的影响,建立了一个新的反应动力学模型．该模型认为P2O5作为易挥发组分参与对电子的竞争,抑制氧迁移(CO2 2e=CO O^2-)主反应的进行．对实验数据的分析和拟合表明了模型的可用性,也辅证了反应的电化学机制．     

EQUILIBRATING PARTITION RATIOS OFNb,Mn AND Si BETWEEN LIQUID IRON AND MgO-SiO_2-MnO SLAG MELTS

The liquid iron containing elements Nb,Mn and Si has been equilibratedwith MgO-SiO_2-MnO slag melts at 1600℃ in a Mo wire-wound resistance furnace with aduration of 4h.The oxygen activities in liquid iron were measured with oxygen sensors.Usingthe known equilibrium constants of concerning reactions and the oxygen activities in liquidiron,the activities of components in the slag melts can be calculated.It was found that the par-tition ratios of Nb.Mn and Si have a close linear relationship with α_(FeO) in logarithmicscale.The dependence of Nb partition ratio on mole fractions of the slag components was al-so obtained.