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。     

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.     

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…     

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。     

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。     

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.     

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。     

Leaching of blended copper slag in microwave oven

Leaching of blended slag (BS) was investigated in a microwave oven using hydrogen peroxide and acetic acid. The BS was a mixture of converter and flash furnace slag containing 51% Fe₂O₃, 3.8% CuO, and 3.2% ZnO. The important variables that influence the metal extraction yield were leaching time, liquid-solid ratio, H₂O₂ and CH₃COOH concentrations. The preferred leaching conditions were as follows: CH₃COOH concentration 4 mol/L; H₂O₂ concentration 4 mol/L; microwave power 900 W; leaching time 30 min; liquid-solid ratio 25 mL/g BS; leaching temperature 100 °C. Under these conditions, the metal extractions of 95% Cu, 1.6% Fe, and 30% Zn were obtained. The results were compared with the traditional leaching results. It is evident that microwave heating causes a reduction in the leaching time. Also, the extraction yield results indicate that selective leaching of BS can be achieved under the preferred conditions. The dissolution kinetic of BS in hydrogen peroxide with acetic acid is controlled by a shrinking unreacted core model equation. The apparent activation energy and reaction order were found to be 16.64 kJ/mol and 1.09, respectively.     

铜在富FeO熔渣中的氧化溶解行为

在1873 K条件下对铜在富FeO熔渣中的氧化溶解行为进行了研究.结果表明:铜氧化物在富FeO熔渣中以Cu2O的形式存在;熔渣中CaO的含量将对铜的氧化溶解产生影响,随着渣中CaO含量的增加,熔渣中的铜含量逐渐下降,但在不同温度下,这种影响的作用各不相同;当温度较高时,渣中CaO含量对铜的氧化溶解影响较大,且随着温度的降低,其影响作用明显变缓;反应体系的氧分压对铜的氧化溶解影响较大,在熔渣中γ(CuO0.5)不变的情况下,铜氧化物的溶解与体系氧分压的四分之一次方之间呈正线性关系.     

LXZM46矿渣立磨机的研制

介绍了中国重型机械研究院有限公司研制的LXZM46矿渣立磨机的工作原理、技术参数及其优化设计。该立磨集烘干、粉磨、分级多重功能于一体,体积紧凑、振动小、无粉尘外逸、生产噪音低、电耗低、单机生产能力大,适用于高炉矿渣和水泥熟料的粉磨。设备采用高度模块化结构,以充分实现机件的可互换性;智能化的控制系统,可使操作、维护简便。     

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。     

熔融钒渣纯氧氧化钙化提钒(英文)

在实验室条件下对熔融态钒渣直接氧化钙化提钒新工艺进行研究。在反应过程中利用纯氧氧化,CaO作为添加剂,硫酸浸出熟料。采用XRD、XPS、SEM及EDS等手段对钒渣熟料进行分析,考察不同CaO/V2O5质量比与硫酸浓度对熟料中钒浸出的影响,并与现行焙烧工艺在能耗方面进行对比。结果表明:钒渣熟料中形成了钒的富集相,钒渣的氧化钙化产物主要为CaV2O5和Ca2V2O7,并对钒酸钙的形成机理进行了阐释;XRD和XPS分析得出熔渣中钒的氧化反应在供氧充足的情况下存在一定限制,CaO的增加能促进五价钒在熔渣中的稳定;在优化的实验条件下(CaO/V2O5质量比0.6,粒度120~150μm,浸出时间2 h,浸出温度90°C,液固比5:1 mL/g,H2SO4浓度20%,搅拌强度500 r/min),钒的浸出率能达到90%;能耗计算得到每处理1000 kg钒渣,利用新工艺可以节约能量1.85×106 kJ。实验与计算结果验证新工艺是一种节能减排的提钒手段。     

High-current metal ion implantation for industrial applications

Ion implantation, as an efficient surface processing technique, has developed to include the implantation of various metallic ions for improving not only wear properties, but also such other surface properties as solid lubrication, fatigue, chemical stability, and engineering reliability. The high-dose metal ion implantation that can be accumulated in a short time over a relatively large implanting area makes metal vapor vacuum arc (MEVVA) source ion implantation well suited to practical surface engineering modification applications.     

采用固相还原法利用工业废渣治理铬渣

采用高温固相还原法,选用廉价工业废渣———鼓风炉渣M作还原剂,利用M渣中残余的C将铬渣中主要以Na2CrO4形式存在的Cr(Ⅵ)还原成Cr(Ⅲ),实现对铬渣的解毒处理。研究了温度、反应时间、铬渣质量分数的影响,确立了实验优化条件,并对终渣的安全性进行了分析。结果表明:质量分数为23%的铬渣在1 350℃反应2 h,终渣中Cr(Ⅵ)浸出值仅为0.063 mg/L,远低于国标GB5085.3—1996规定限值1.5 mg/L,该方法简单、以废治废、解毒彻底,并利用终渣制备了高掺量废渣空心砌块,强度等级达到《GB 8239—1997普通混凝土小型空心砌块》MU7.5要求,可作建筑物承重墙使用,满足我国废渣治理大力提倡的无害化、资源化要求,成为铬渣处理处置的一种新途径。     

Effect of ion implantation upon erosion resistance of polyimide films in space environment

The atomic oxygen （AO） resistance of Si ion implanted polyimide films in the ground-based AO simulation facility was investigated by scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS） and Auger electron spectroscopy （AES）. The results show that at the initial stage of AO exposure the implanted sample has a small mass change, and then is stabilized. The erosion yield of the implanted polyimide film decreases by about two orders of magnitude compared with that of the polyimide film. The analysis through XPS and AES indicates that a continuous high-quality protective oxide-based （SiO2） surface layer is formed on the implanted polyimide films after the AO exposure. It can provide high-quality erosion protection for these materials. The implanted polyimide fully restores its original color and the carbonization effect disappears on the whole after AO exposure. Thermal-optical properties and surface morphology of the implanted polyimide materials are not altered. The modified materials have a markedly increased erosion resistance in AO environment.