Application of ionic liquids in hydrometallurgy of nonferrous metals

Ionic liquids as green solvents have shown important application in the extraction and separation of nonferrous metals.The new application perspective,the important fundamental and the applied studies of the extraction and separation of nonferrous metals in ionic liquids,including the dissolution and corrosion of metal and metal oxide,hydrometallurgy of chalcopyrite and metallic oxidized ore,and extraction and separation of metal ions,are introduced.     

Synthesis and properties of nanocrystalline nonferrous metals prepared by flow-levitation-molding method

Nanocrystalline nonferrous metals （Cu, A1, and Ag） were synthesized by flow-levitation-molding method. The microstructure of the as-prepared nanocrystalline metals was characterized by XRD and FESEM. The microhardness and electrical resistivity were tested by the HMV-2 type Microhardness Tester and 6157 type Electrometer, respectively. The synthesis process was also studied. The results show that the spheriform particles in nanocrystalline metals have average grain size of 20-30 nm. The relative density of nanocrystalline Cu, A1, and Ag are 95.1%, 98.1% and 98.3%, respectively. The microhardness of nanocrystalline Cu, Al and Ag are 2.01, 2.11 and 1.26 GPa respectively, which are larger than those of their coarse-grained counterparts by the factor of 4.5, 14, and 2.5, respectively. The electrical resistivity of nanocrystalline Cu at room temperature is 1.5× 10^-7Ω.m, which is higher than coarse-grained Cu by a factor of 7.5. The pressure is the predominant factor influencing the density of the as-prepared nanocrystalline nonferrous metals.     

Industrial texture control in the production of ribbons from nonferrous metals

Processes that occur in manufacturing metallic products are accompanied by the formation and change of predominant crystallographic orientations of grams or textures. In the present work the principles and some practical techniques of control over metallic products based on measuring the texture parameters are formulated. This has been used to develop continuous nondestructive control of the properties of alloys in technological lines. On-line texture control of technological processes is described as applied to continuous annealing of copper, brass, and aluminum ribbons used at plants for processing nonferrous metals.Translated from Metallo!ovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 32–35, May, 1995.In experimental part of the work was done in collaboration with A. I. Kekalo, O. A. Avdyushkin, L. Yu. Luzhbina, M. z. Pevzner, N. S. Yanburenko, N. Yu. Pappe, K. I. Shckekin, Yu. S. Grigor'ev, and A. A. Evgrafov,     

金属退火硬化现象及机理的研究进展

通常金属进行退火时都会发生软化现象,而对于一些特殊的金属或者合金,将出现退火硬化的反常现象。对纯金属、铜合金、镍钨合金、锌铝合金和铝合金等体系中退火硬化现象及机理进行了总结与分析。铝钪、铝镱和铝锆系合金中存在铸态直接退火硬化现象,而其它合金体系需要进行冷变形才会出现退火硬化现象。退火硬化的机理主要包括:晶界溶质偏析、晶界弛豫、第二相颗粒的晶界钉扎、位错源限制硬化、溶质偏析对孪晶边界迁移或位错滑动的钉扎效应、退火孪晶、第二相纳米粒子强化等。     

稀土金属提纯方法与研究进展

对各种提纯稀土金属方法的机理进行了阐述,包括真空熔炼、电解精炼、真空蒸馏/升华、熔盐萃取、区域熔炼、固态电迁移、电化学脱氧、外吸气剂法、等离子体熔炼(通氢气或通氩气)等。对研究现状和提纯效果进行了总结。杂质去除需采用多种手段结合,同时提升装备水平,以达到提高提纯效果、降低成本、缩短生产周期的目的。     

Crystal-structural features of pretransition phenomena and thermoelastic martensitic transformations in alloys of nonferrous metals

The unusual and practically important phenomena and physical properties that are caused by reversible martensitic transformations occurring mainly in alloys and compounds of nonferrous metals have been analyzed. The main types of martensitic transformations, their crystal-geometrical features and structure-morphological characteristics, the nature and structural mechanisms of reversibility, and the phenomenon of thermoelasticity have been considered. Structural mechanisms of atomic rearrangements upon martensitic transformations have been discussed, and premartensitic phenomena and their relation to martensitic transformations have been analyzed.     

Research progress on squeeze casting in China

Squeeze casting is a technology with short route,high efficiency and precise forming,possessing features of casting and plastic processing.It is widely used to produce high performance metallic structural parts.As energy conservation and environmental protection concerns have risen,lightweight and high performance metal parts are urgently needed,which accelerated the development of squeeze casting technology over the past two decades in China.In this paper,research progress on squeeze casting alloys,typical parts manufacturing and development of squeeze casting equipment in China are introduced.The future trend and development priorities of squeeze casting are discussed.     

行业整合背景下的中国有色金属企业技术效率评价

自2009年以来,我国有色金属产业在政府推动下开展了行业整合。在此,对我国2007?2011年间有色金属企业的技术效率及其变动进行研究。在以有色金属上市公司作为研究样本的基础上,采用 DEA 的方法分别测算有色金属矿釆选企业和有色金属冶炼及压延加工企业的技术效率。研究发现,两个行业,无论是纯技术效率还是规模效率,无效企业居多。行业纯技术效率和规模效率均值在2009年之后偏低。其中,有色金属冶炼及压延加工企业效率值的波动较大。少数龙头企业保持着行业内相对有效的纯技术效率和规模效率,但大多数龙头企业的技术效率值则在2009年之后出现了大幅度的下降。     

金属板料各向异性断裂模型及断裂实验研究进展

对金属板料各向异性断裂模型及断裂实验目前的研究进展进行了综述和分析,指出细观损伤力学模型通过考虑基体的塑性各向异性,孔洞的形状、大小及空间分布来描述变形过程中损伤的各向异性演化;连续介质损伤力学模型(CDM)通过将标量形式的损伤因子替换成一个损伤张量来描述材料的各向异性损伤;非耦合型各向异性断裂模型通过改变等效塑性应变增量的度量方法或对应力张量进行线性变换两种方法来描述材料的各向异性断裂。可以通过设计一系列具有不同几何形状的试样或者通过在试样边界上施加不同的载荷组合这两种途径来实现不同应力状态下的断裂实验。此外,开展金属板料厚度方向的实验是今后发展的一个重要方向。     

新中国重型机械装备业发展与中国重型院的科技进步

回顾了中国重型机械装备业的发展历程,阐述了装备技术在不同历史阶段的发展重点及科技成果及中国重型机械研究院等重型装备企业所取得的成就,展望了重型装备业的发展趋势。     

Co-intensification of gold leaching with heavy metals and hydrogen peroxide

Co-intensification was researched to accelerate gold leaching with regards to its electrochemical nature by using anodic intensifiers of heavy metal ions (Pb2+, Bi3+, Tl+, Hg2+ and Ag+) on the basis of hydrogen peroxide assistant leaching on three different types of materials which were classified as a refractory sulphide gold concentrate, an easily leachable sulphide gold concentrate, and a low grade oxide gold ore according to their leaching characteristics. The results showed that, favorable co-intensification effects on the three materials were obtained and leaching time of gold was effectively shortened to no longer than 12 h from 16 to 24 h for hydrogen peroxide assistant leaching. For the five tested heavy metal ions, Bi3+and Tl+ presented co-intensifying effect on all the three materials, and Hg2+ caused co-intensifying effect on both refractory and easily leachable sulphide gold concentrates, and Pb2+ and Ag+ only had co-intensifying effect on the easily leachable sulphide gold concentrate.     

钢/铝异种金属点焊研究进展综述

基于电阻点焊过程中工艺信号特征,在不同间距、不同间隙和不同间距与间隙3种条件下,引入相关性分析方法分析工艺信号与熔核直径之间的相关性,并建立基于麻雀搜索算法-BP神经网络(sparrow search algorithm- back propagation neural network, SSA-BP)的电阻点焊质量预测模型,将功率、焊接电流、焊接电压和动态电阻作为预测模型输入特征. 结果表明,经麻雀搜索算法优化后的BP神经网络在测试集上的决定系数R²、均方误差(mean-square error, MSE)、均方根误差(root mean square error, RMSE)和平均绝对误差(mean absolute error, MAE)分别为0.95,1.55,1.24和0.90,均优于BP模型. 获得了功率、焊接电流、焊接电压和动态电阻与熔核直径的映射关系,可为焊接的工艺参数设计提供依据.

     

基于元胞自动机的金属静态再结晶行为研究进展

静态再结晶是材料变形后通过热处理来改变组织状态的重要现象.本文重点综述总结了金属静态再结晶行为的数值模拟研究,首先简要介绍了计算材料科学中常用的元胞自动机(Cellular automata,CA)模拟方法,然后分别对元胞自动机模拟的动力学模型和物理模型发展进行详细综述,并分析总结了近年来元胞自动机在金属及其合金静态再...     

增材制造W-Ni-Fe系高比重合金的研究进展

金属增材制造技术是从20世纪90年代初期发展起来的一项先进制造技术,能够实现高性能复杂结构金属零件的无模具、快速、全致密近净成形。高比重W-Ni-Fe合金由于具有高密度、高强度和高塑性等特性,广泛应用于国防工业和国民经济领域。近年来,W-Ni-Fe高比重钨合金的增材制造受到了广泛关注。本文综述了国内外研究机构采用选区激光熔化(SLM)技术、激光熔化沉积(LMD)技术、选区电子束熔化(EBSM)技术和粘接剂喷射打印(BJP)技术4种增材制造技术制备W-Ni-Fe合金的研究进展,从成形工艺、成形件微观组织和力学性能等方面进行了分析,并对未来研究趋势做了预测。     

广州市不同来源污泥中重金属的含量和形态分布特征

采集了广州市4个不同来源污水处理厂及1个工业废水处理厂的脱水污泥,分析污泥的理化性质参数和重金属(Zn、Cu、Pb、Cr、Ni、Mn、Cd)的含量,重点利用BCR法研究不同污泥中重金属的赋存形态。结果表明,脱水污泥中有机质含量较高,并且富含N和P营养成分。污泥中重金属含量差别较大,其中Mn、Zn、Cu含量高,其次是Ni、Pb、Cr,Cd含量最低,但5个不同来源污泥中重金属的含量都高出广州市农田背景值。除了S1污水污泥中的Cu、Cd及S1、S2、S5污水污泥中的Ni外,其他污泥中重金属的含量都低于国家污泥农用控制标准(GB 18918-2002)。BCR连续提取法表明,污泥中的Mn和Zn主要以酸可交换态及易还原态存在,Cu和Cr主要以可氧化态和残渣态存在,Pb大部分存在于残渣态,Ni和Cd的形态分布没有明显特征。     

Research and development of rare earth permanent magnets in China

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水域底泥中重金属Cd与Pb释放规律的数值模拟

采用实验研究与数值模拟相结合的方法,研究某水域底泥中典型重金属污染物Cd与Pb再释放过程和释放速率.结果表明,底泥中Cd和Pb的释放规律分为快速释放和动态平衡两个阶段,与准二级动力学方程具有较好的匹配度,相关系数R2大于0.99.随着河流流速的加快,底泥中重金属的释放速率增大.分析表明,该区域水质可以在3 h内超过地表...