埋弧焊焊接过程中电化学致氧的研究

传统的焊接冶金观点认为焊接过程的增氧机制是热经学作用所致，近年来，一些焊接冶金学者提出了熔滴/液态金属界面间电化学致氧的观点。在本研究过程中，采用自制不同碱度的系列烧结焊剂，配合低碳钢焊丝进行焊接，利用LECO氧氦分析仪测量溶滴的氧含量。结果表明：在埋弧焊过程中确实存在电化学致氧现象，且电化学致氧量随碱度的增大而增大。     

MgO-CaO-SiO2焊接熔渣离子活度的热力学分析

针对焊接熔渣分子理论及离子理论存在的局限,基于冶金界近年来提出的熔渣共存理论,结合MgO-CaO-SiO2高温三元相图确定的结构单元,利用质量平衡原理建立了MgO-CaO-SiO2三元熔渣离子活度热力学计算模型,并借助于Matlab计算工具进行数值求解.计算结果表明,该模型可同时兼顾熔渣的分子理论和离子理论,离子活度随碱度的变化与碱度理论及直流焊接冶金电化学实验结果一致,在焊接化学冶金定量研究方面显示出良好的应用前景.     

电化学作用对直流焊接熔滴金属致氧量的影响

在对熔滴金属电化学致氧动力学分析基础上,用试验室自行设计制作的不同碱度系列烧结焊剂,采用在水冷铜板表面进行快速直流埋弧焊接方法提取出无熔池熔滴金属,以获取出熔滴金属质量几何信息并进而进行冶金电化学致氧量分析.结果表明,随着熔渣碱度的增大,钢-渣界面电化学作用愈加强烈,冶金电化学致氧量也愈加突出.就所研究CaO-Al2O3-SiO2渣系而言,当碱度值增至1.52时,冶金电化学致氧程度几乎可以达到与冶金热化学相当的程度,因而在直流焊接工艺制订及高碱度焊接材料研制中是一不可忽视的冶金致氧因素.     

Mechanism of oxygen dissolution in metallic zirconium

The oxygen dissolution in metallic zirconium has been investigated by electrochemical and X-ray techniques. The mechanism of the zirconium oxidation process is proposed. It is shown that during the first stage of the process, oxygen dissolves in the metal matrix acting as an electron donor. The region of oxygen solid solutions in zirconium reaches 25 at.% oxygen. After oxygen saturation of the metal surface the second stage starts; zirconium oxides form.     

锂离子电池正极材料LiNi1-yAlyO2的制备及性能

在高温增加氧气压力的条件下 ,通过固态反应合成了锂离子电池正极材料LiNi1-yAlyO2 。讨论了合成条件对产物的电化学性能的影响 ,得到最佳的反应条件是 :2个恒温阶段的反应时间为 8h和 10h ;氧气压力为0 .2 0MPa ;反应温度 80 0℃ ;反应物Li,Ni,Al之间的摩尔比为 1.1∶0 .95∶0 .0 5。合成出具有晶型完整、电化学性能优良的LiNi0 .95Al0 .0 5O2 产品 ,其放电容量达 182 .3mA·h/g。结果表明 ,Al3 + 的添加对LiNiO2 的结构及电化学性能有较大的改善。     

硅渣中金属离子的分离和利用

本实验研究了硅渣用盐酸处理后，加入动物胶，分离出硅，然后通过调节pH值，让溶液中的钙、钠、铝分离开。钙、铝的化合物，过滤后回到氧化铝流程，进行再利用，溶液通过浓缩结晶，回到生产硅产品的流程中去，氧化钠回收利用。本试验为探索出硅渣处理，促进氧化铝生产的发展，搞好环境保护和提高经济效益，提供重要方法。     

Effect of electrochemical reactions droplet metal in direct current on oxygen contamination of submerged arc welding

Agglomerated fluxes with different basicity index designed in laboratory were used to study electrochemical reactions between slag and metal in submerged arc welding under both power polarities. The droplet metal oxygen and nitrogen contents were measured using oxygen-nitrogen instrument in order to analyze indirectly metallurgy electrochemical reactions taking place in cathode and anode of welding arc. The results show that just in the period of droplet growth at the tip of consumable electrode the electrochemical oxygen contamination is produced in the case of direct current electrode positive polarity whereas electrochemical oxygen lost in electrode negative polarity. Furthermore, the results indicate that the basicity index of molten slag has great influence upon electrochemical reaction. With basicity index increasing, the effect of oxygen transferring resulted from electrochemistry becomes more evident for reacting dynamics depended on ion characteristics of molten slag. The effect of basicity index on metal-slag electrochemical reaction is contrary to traditional thermo-chemical reaction and therefore it is necessary to be considered as a metallurgy factor.     

炉渣中氧离子迁移的电化学模型

对渣相中氧离子迁移的电化学进行研究，提出具有电化学特征的渣相氧离子流动力学模型，此模型能较为全面地解释各种反应现象，实验数据与模型计算的对比，证明所提出的反应机制的正确性。     

Recovery of valuable metals from spent lithium ion batteries by smelting reduction process based on FeO–SiO2–Al2O3 slag system

A novel smelting reduction process based on FeO–SiO₂–Al₂O₃ slag system for spent lithium ion batteries with Al cans was developed, while using copper slag as the only slag former. The feasibility of the process and the mechanism of copper loss in slag were investigated. 98.83% Co, 98.39% Ni and 93.57% Cu were recovered under the optimum conditions of slag former/battery mass ratio of 4.0:1, smelting temperature of 1723 K, and smelting mass ratio of time of 30 min. The FeO–SiO₂–Al₂O₃ slag system for the smelting process is appropriate under the conditions of m(FeO):m(SiO₂)=0.58:1–1.03:1, and 17.19%–21.52% Al₂O₃ content. The obtained alloy was mainly composed of Fe–Co–Cu–Ni solid solution including small amounts of matte. The obtained slag mainly consisted of fayalite and hercynite. Meanwhile, the mechanism of copper loss is the mechanical entrainment from strip-like fayalite particles in the main form of copper sulfide and metallic copper.     

Study of decomposing carbonyl slag

1 Introduction Carbonyl slag is a kind of solid from the material with nickel by carbonylation. It usually contains Cu, Ni, Co, Fe, S, As, Sb, Au, Ag and platinum metals, and holds great recovery value. At present, with the development of the technology o…     

磷酸盐前驱体对泡沫镍上生长的镍/铁羟基氢氧化物形貌及析氧反应性能的影响（英文）

通过共沉积法和电化学激活法在泡沫镍网上生长制备镍/铁羟基氢氧化物纳米片。研究发现,不同磷酸盐前驱体(Na₃PO₄、Na₂HPO₄和NaH₂PO₄)对最终催化剂的形貌及析氧反应活性有不同的影响。使用Na₂HPO₄制备的镍/铁羟基氢氧氯化物纳米片在1 mol/L KOH溶液中电流密度达到50 mA/cm²时所需过电位为205 mV,Tafel斜率低至30 mV/dec,并可以在后续稳定性测试中保持稳定20 h。     

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.     

生物浸出体系中中等嗜热菌对锌冶炼窑渣中金属的提取及其电化学特性的影响(英文)

研究中等嗜热菌对锌冶炼窑渣中金属提取的影响以及生物浸出过程中锌冶炼窑渣碳糊电极的电化学特性。结果表明,在矿浆浓度2%、pH1.0、温度65°C、转速为120r/min的浸出条件下,去除生物浸出体系中吸附菌后,废渣中Fe、Cu和Zn的浸出率分别为86.7%、90.3%和66.7%,而在没有去除吸附菌体系中3种金属的浸出率分别为91.9%、96.0%和84.5%。对生物浸出渣和酸浸渣表面细菌分泌物进行FT-IR测试分析可知,生物浸出渣颗粒表面出现了新的官能团振动峰,如1007cm1和1193cm1处的峰,间接说明残渣颗粒表面吸附细菌的存在。生物浸出体系和空白体系的循环伏安曲线和塔菲尔曲线特性进一步表明生物浸出体系中细菌促进了锌冶炼窑渣中有价金属的溶出。     

熔融镍渣等温氧化动力学研究

研究了富铁熔融镍渣在空气气氛下的等温氧化动力学行为。利用高温激光共聚焦显微镜(HT-CLSM)确定三元碱度0.6调质镍渣的实际熔融温度(液相线温度)为1488℃。通过管式炉等温氧化试验，获取温度1500～1575℃下熔融镍渣氧化过程Fe²⁺浓度-时间曲线，采用微分法和Arrhenius方程计算出熔渣中Fe²⁺的氧化反应级数为1.45～1.26，表观活化能为286.83 k J/mol，明确熔融镍渣氧化动力学主要受扩散传质控速。基于双膜理论和渗透理论，估算出1500～1575℃熔渣中氧的扩散系数分别为2.02×10^-9～4.42×10^-9 m²/s和0.50×10^-9～2.19×10^-9 m²/s，双膜理论估算出的氧扩散系数更具参考意义。     

挡渣出钢过程中挡渣器使用浅见

为了提高转炉在出钢时减少下渣量,通过对比各厂现有挡渣出钢技术的分析研究,结合本厂现有的技术装备,对挡渣出钢所使用的挡渣器提出了改进建议并在实际生产过程中进行应用。     

用于氧还原反应的氮掺杂空心多孔碳球封装的过渡金属氮化物的制备和性能

通过浸渍和热处理方法制备一系列氮掺杂空心多孔碳球(NHPCS)封装的过渡金属氮化物(MxNy,M=Fe,Co,Ni)纳米颗粒复合材料.此纳米复合材料兼具氮化物的高催化活性和氮掺杂多孔碳球的高效传质特性.氧气还原反应结果表明,Fe2N/NHPCS表现出优异的催化性能,其具有较高的起始电位(0.96 V)、电子转移数(～4...     

银基体上铜等离子体基离子注入层的成分分布

研究了银基体上铜等离子体基离子注入 (CuPBII)层成分深度分布与试验工艺参数的关系。选择影响注入离子能量的脉冲偏压和注入剂量的不平衡磁控靶放电电流和靶基距作为试验参数 ,用X射线光电子谱 (XPS)进行注入层成分深度分析。结果表明 ,对较高的脉冲偏压 (80kV)、中等的磁控靶电流 (75mA)和近的靶基距 (2 0 0mm) ,容易形成厚的银铜过渡层 (7.6μm) ,且铜离子注入、铜原子的反冲注入与铜的沉积很好地匹配。与气体等离子体基离子注入不同 ,铜的沉积速率成为影响银铜过渡层的又一决定因素。     

KINETICS OF DESULPHURIZATION IN PERMANENT CONTACT OF SLAG AND STEEL

The curve of % S vs reaction time is described quantitatively based on the electrochemicalmodel directly deduced from the principle of electrochemistry as well as the given method forcalculating the initial oxygen potential along slag/steel interface.The calculated data is ingood agreement with the experimental results.During desulphurization,both L_s~* and L_s,the sulphur partition along the interface andthat in the bulk,go up in association with the descending of oxygen potential along interface.The plot of L_s~* against reaction time follows a parabolic curve,while that of L_s is ofhyperbola type.Correspondingly,on curves of driving force parameter vs reaction tone,eithercalculated or experimental,a hump occurs.     

金属复合低碳镁碳渣线砖氧化剥落分析

金属Al/Si复合低碳MgO-C砖在冶炼品种钢的210 t钢包渣线试用,取得良好使用效果。采用XRD、SEM、EDS对用后残砖分段带进行了物相和显微结构分析,结果表明:用后残砖可分为原砖带、原砖渐变带和氧化带三个段带;原砖渐变带里Al和Si与C和N2反应,原位生成Al4C3、AlN和SiC,有利于提高高温强度和热震稳定性;氧化带里的AlN和SiC先后逐渐被氧化,并与MgO反应生成镁铝尖晶石和镁橄榄石,结构比较疏松,抗热震稳定性有所减弱。可以认为该砖的损毁原因主要是氧化后的结构剥落。今后改进的方向主要为改善材料氧化后的热震稳定性。     

钢包顶渣改质对抑制旋涡卷渣的影响

钢包加盖能够显著提升钢包的保温效果,助力钢铁企业节能降耗。但钢包加盖条件下顶渣温度较高、流动性好,更易引起浇注末期旋涡卷渣,铸坯夹渣缺陷率升高。开展了顶渣改质抑制旋涡卷渣的工艺研究,以高碱度渣为研究对象,通过相图分析确定了炉渣改质增黏的基本思路,利用FactSage软件对多组改质渣系进行黏度计算。结果表明,添加石灰或轻烧白云石都有助于增大炉渣黏度,两者增黏效果相近,炉渣黏度测量试验也验证了上述结论。利用BaCO₃示踪法开展了顶渣改质的工业试验,结果表明,炉渣改质后钢中大尺寸夹杂物数量大大减少。顶渣改质新工艺在现场应用后,铸坯平均夹渣缺陷率由0.57%降低至0.42%。