中国铜产品生命周期的熵分析

熵,是描述热力学系统平衡态的一个状态函数。为确定铜产品生命周期中含铜物质的聚集和散失程度,将热力学中"熵"这一指标引入到物流分析中,给出了物流分析中"熵"的分布及其计算方法,在中国2005年铜产品生命周期分析的基础上,计算了铜循环整个过程中,即精炼铜的生产阶段、铜制品的加工制造阶段、铜制品的使用阶段和报废铜制品的回收阶段的熵的变化,得到5个节点处的相对熵值分别为0.25596,0.04562,0.23690,0.60470和0.24866,整个过程中的相对熵变化率为-2.85%,即经过一个生命周期,含铜物质聚集度在提高,并与2002年铜产品生命周期的熵分析结果进行了比较。在2005年铜产品生命周期熵分析的基础上,通过两种不同技术指标下的情景分析,得出了减少采、选矿环节和熔炼环节尾矿和熔渣中铜的损失量,提高报废铜制品的回收率和折旧废铜的含铜百分比等措施,将会有效地降低铜产品生命周期的熵值增加。相信随着物质流分析方法和理论研究的进一步深入,熵在物质流分析中的应用范围和程度也会愈来愈广泛和深入。

中国铜循环的熵分析

为确定铜循环过程中含铜物质的聚集和散失程度,将热力学中"熵"这一指标引入到物流分析中,给出了物流分析中"熵"的分布及其计算方法.在中国2002年铜循环现状分析的基础上,计算了铜循环整个过程中,即精炼铜的生产阶段、铜制品的加工制造阶段、铜制品的使用阶段和报废铜制品的回收阶段熵的变化,得到5个节点处的相对熵值分别为0.32149,0.06337,0.23946,0.59919和0.50786,整个过程中的相对熵变化率为57.97%,即含铜物质趋于分散,且较严重.提出了减少采/选矿环节、熔炼环节尾矿和熔渣中铜的损失量,提高报废铜制品的回收率等措施,将会有效地降低铜循环的熵值增加.

粗铜熔炼技术改造

本文介绍了我国粗铜熔炼现状,找出了与世界炼铜先进水平的差距,综述了各种炼铜方法的优缺点及其技术经济指标。通过冶金计算阐明了采用富氧鼓风及提高铜锍品位的效果。提出了我国粗铜熔炼技术改造的方向。

勠力“铜”心 扬帆远航——党的十八大以来中国铜业有限公司改革发展掠影

今年1月至9月,中国铜业有限公司实现利润7.43亿元,完成全年奋斗目标的92.88%,同比增长167.28%,呈现出期待已久的喜人发展势头。狂澜既挽,巨舰催发。中铜人正按照＂多盈利、超常规、减问题、快改革＂的要求,把握市场,锐意改革,聚力乘势,赢取未来,以优异的业绩迎接党的十九大胜利召开!

Tribological and electric-arc behaviors of carbon/copper pair during sliding friction process with electric current applied

The tribological behaviors of carbon block sliding against copper ring with and without electric current applied were investigated by using an advanced multifunctional friction and wear tester, and the electric-arc behaviors were analyzed in detail. The results show that the normal load is one of the main controlling factors for generation of electric arc during friction process with electric current applied. The strength of electric arc is enhanced with the decrease of normal loads and the increase of electric currents. The unstable friction process and the fluctuated dynamic friction coefficients are strongly dependent upon the electric arc. The wear volumes and the wear mechanism of carbon brush were affected by the electric arc obviously. As no electric arc occurs, no clear discrepancy of the wear volumes of the carbon samples with and without electric current applied could be detected. While the wear mechanisms are mainly mechanical wear. However, under the condition of the electric arc appearance, the wear volume of carbon with electric current applied increases much more rapidly than that without electric current applied and also increases obviously with the increase of electric current strengths and the decrease of normal loads. The wear mechanisms of carbon block are mainly electric arc ablation accompanying with adhesive wear and material transferring.

On-line detection of Cu(II) in bioleaching system by anodic stripping differential pulse voltammetry

On-line Cu （II） ion concentration detection in bioleaching system was achieved by anodic stripping differential pulse voltammetry （ASDPV）. Good linearity between Cu （II） concentration and oxidation peak current was obtained when Cu （II） existed in 0K media in the concentration range of 1μmol/L （64μg/L） to 1 mmol/L （64 mg/L）. Moreover, when 0.2 mol/L KCl was added into this media, the linear detection range could be extended from 1 mmol/L to 100 mmol/L （6.4 g/L）. The reduction of Cu （II） to metallic copper was shown to proceed as two successive single-electron transfer reactions involving an intermediate chemical step where the cuprous ion （Cu＋） was complexed by chloride to form the dichlorocuprous anion （CuCl-）. In addition, interference effect was also investigated when Fe3＋existed in the media, which was the common situation in the copper bioleaching system. The results showed no interference effect once the concentration of Fe3＋was less than 100 mmol/L （5.6 g/L）.

Effect of electrical current on tribological property of Cu matrix composite reinforced by carbon nanotubes

Cu matrix composite reinforced with 10%（volume fraction） carbon nanotubes（CNTs/Cu） and pure Cu bulk were prepared by powder metallurgy techniques under the same consolidation processing condition.The effect of electrical current on tribological property of the materials was investigated by using a pin-on-disk friction and wear tester.The results show that the friction coefficient and wear rate of CNTs/Cu composite as well as those of pure Cu bulk increase with increasing the electrical current without exception,and the effect of electrical current is more obvious on tribological property of pure Cu bulk than on that of CNTs/Cu composite;the dominant wear mechanisms are arc erosion wear and plastic flow deformation,respectively;CNTs can improve tribological property of Cu matrix composites with electrical current.

Development and Application of On-Line Corrosion Monitoring Device for Condenser Tube

This paper introduces the development and industrial application of an on-line corrosion monitoring device for condenser tubes. Corrosion sensors are made up of representative condenser tubes chosen by eddy current test, which enable the monitoring result to be consistent with the corrosion of actual condenser tubes. Localized corrosion rate of condenser tubes can be measured indirectly by a galvanic couple made up of tube segments with and without pits. Using this technology, corrosion problems can be found in time and accurately, and anticorrosive measures be made more economic and effective. Applications in two power plants showed the corrosion measurements are fast and accurate.

Hot deformation behavior and processing maps of Mg-Zn-Cu-Zr magnesium alloy

The deformation behaviors of a new quaternary Mg-6Zn-1.5Cu-0.5Zr alloy at temperatures of 523-673 K and strain rates of 0.001-1 s-1 were studied by compressive tests using a Gleeble 3800 thermal-simulator.The results show that the flow stress increases as the deformation temperature decreases or as the strain rate increases.A strain-dependent constitutive equation and a feed-forward back-propagation artificial neural network were used to predict flow stress,which showed good agreement with experimental data.The processing map suggests that the domains of 643-673 K and 0.001-0.01 s-1 are corresponded to optimum conditions for hot working of the T4-treated Mg-6Zn-1.5Cu-0.5Zr alloy.

Effects of direct current electric field on corrosion behaviour of copper, Cl- ion migration behaviour and dendrites growth under thin electrolyte layer

Effect of direct current electric field （DCEF） on corrosion behaviour of copper printed circuit board （PCB-Cu）, Cl-ion migration behaviour, dendrites growth under thin electrolyte layer was investigated using potentiodynamic polarization and scanning electron microscopy （SEM） with energy dispersive spectrometer （EDS）. Results indicate that DCEF decreases the corrosion of PCB-Cu;Cl-ions directionally migrate from the negative pole to the positive pole, and enrich on the surface of the positive pole, which causes serious localized corrosion; dendrites grow on the surface of the negative pole, and the rate and scale of dendrite growth become faster and greater with the increase of external voltage and exposure time, respectively.

小议一组“毛边”宣统通宝小样钱

光绪三十四年(1908年)光绪皇帝驾崩,醇亲王之子溥仪继位,次年改元"宣统",在位仅3年,1911年被"辛亥革命"所推翻,为封建社会最后一位皇帝。宣统年间,全国各省几乎都已停铸制钱,仅宝泉局铸过一种重一钱的"宣统通宝"小平钱,数量也不多,分为大小两种。

Copper and arsenic substance flow analysis of pyrometallurgical process for copper production

The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.

Quality index and hot tearing susceptibility of Al-7Si-0.35Mg-xCu alloys

The effects of Cu addition（0.5%, 1%, 1.5%, 2%, and 3%, mass fraction） on the quality index（Qi） and hot tearing susceptibility（HTS） of A356 alloy were investigated. According to the results, Cu addition up to 1.5% increases the Qi by almost 10%, which seems to be due to its solid solution strengthening and dispersion hardening effect of Cu-rich Al2Cu and AlMgCuSi compounds. However, further addition of Cu（up to 3%） decreases the Qi by almost 12%, which is likely due to the reduction of tensile strength and elongation caused by increased volume fraction of brittle Cu-rich intermetallics and microporosities in the microstructure. It is also found that Cu increases the HTS of A356 alloy measured by constrained rod casting method. According to the thermal analysis results, Cu widens the solidification range of the alloy, which in turn, decreases its fluidity and increases the time period during which the mushy-state alloy is exposed to the hot tearing susceptible zone. SEM examination of the hot tear surfaces in high-Cu alloys also demonstrates their rough nature and the occurrence of interdendritic/intergranular microcracks as convincing evidences for the initiation of hot tears in the late stages of solidification in which there is not enough time for crack healing.

Precipitation and gettering behaviors of copper in multicrystalline silicon used for solar cells

The precipitation and gettering behaviors of copper （Cu） at different defective regions in multicrystalline silicon were investigated by combining scanning infrared microscopy, optical microscopy, inductively coupled plasma mass spectrometry and microwave photo-conductance decay. It is found that the behaviors of Cu precipitation are strongly dependent on the defect density. Most of the Cu contaminants tend to form precipitates homogeneously in the low density defect region, while they mostly segregate at the defects and form precipitates heterogeneously in the high density defect region. In the case of heavy contamination, the Cu precipitate can significantly reduce the carrier lifetime of multicrystalline silicon due to their Schottkydiode behavior in the silicon substrate. A 900 °C rap thermal process （RTP） phosphorus gettering anneal cannot be sufficiently effective to remove the Cu precipitates in these two regions.

Influence of welding parameters on material flow,mechanical property and intermetallic characterization of friction stir welded AA6063 to HCP copper dissimilar butt joint without offset

Joining of dissimilar aluminium-copper is an emerging area of interest for both research and industry due to its complex nature.Friction stir welding was attempted to evaluate the joint strength without offset at the butt line between AA6063 to HCP copper sheet under different combination of rotational speed of 800 and 1000 r/min and travel speed of 20 and 40 mm/min.Material flow was studied in detail for different combinations of parameters with optical microscopy and elemental mapping by energy dispersive X-ray spectroscopy（EDS）.The results were correlated with the microstructural characteristics and formation of intermetallics at the bond interface using microhardness test and X-ray diffraction（XRD） technique.Material flow clearly suggests that energy input at 800 r/min and 20 mm/min is sufficient to plasticize both the materials with formation of higher amount of thermodynamically stable and hard intermetallic phases Al4Cu9 and Al Cu4（slower cooling rate of 88 K/s） than that at 800 r/min and 40 mm/min（faster cooling rate of 154 K/s）,attributed maximum joint strength（~78.6% of aluminium base metal）.

Silane coupling agent treated copper foil as a current collector for silicon anode

Since the volume variation of silicon particles during cycling,the binding spots between Cu current collector and silicon anode raised to be one of the critical binding problems.In this work,an amino-modified Cu current collector(Cu^(*))is fabricated to tackle this issue.The amino groups on Cu^(*)surface increase its hydrophilicity,which is conducive to the curing process of aqueous slurry on its surface.Meanwhile,these amino groups can form abundant amide bonds with carboxyl groups from the adopted polyacrylic acid(PAA)binder.The combined action composed of the covalent bond and mechanical interlocking could reduce the contact loss inside the electrode.However,high concentration silane coupling agent treatment will weaken the surface roughness of Cu^(*)and weaken mechanical interlocking.What is more,the insulation of silane coupling agent reduces the conductivity of Cu and increases the impedance of battery.Considering the effect of silane coupling agent comprehensively,electrochemical performance of Cu^(*)-0.05%is best.

浅析四滑块同步电缆压接设备的设计思路

简要介绍了常规压模对电缆汇流夹产品质量的影响以及解决该问题所采取的措施和方式,阐明了四滑块同步电缆压接设备的设计思路和工作原理。

Kinetics of acid-oxygen leaching of low-sulfur Ni-Cu matte at atmospheric pressure

The leaching of low-sulfur Ni-Cu matte in acid-oxygen(CuSO4-H2SO4-O2)solution at atmospheric pressure was researched.This matte was obtained from high grade Ni-Cu matte by magnetic separation,which mainly contained Ni-Cu alloy and a small quantity of sulfides.The effects of temperature,agitation speed,oxygen flow rate,particle size,acid concentration and concentration of copper ion were studied.It is found that the matte particles are leached by shrinking core mechanism and the leaching process is electrochemically controlled.In a temperature range of 30-60℃,the surface reaction is rate-limiting step,with an apparent activation energy of 41.9 kJ/mol.But at higher temperature(70-85℃),the rate process is controlled by diffusion through the product layer,with an apparent activation energy of 7.3 kJ/mol.

Mathematical model for coupled reactive flow and solute transport during heap bioleaching of copper sulfide

Based on the momentum and mass conservation equations, a comprehensive model of heap bioleaching process is developed to investigate the interaction between chemical reactions, solution flow, gas flow, and solute transport within the leaching system. The governing equations are solved numerically using the COMSOL Multiphysics software for the coupled reactive flow and solute transport at micro-scale, meso-scale and macro-scale levels. At or near the surface of ore particle, the acid concentration is relatively higher than that in the central area, while the concentration gradient decreases after 72 d of leaching. The flow simulation between ore particles by combining X-ray CT technology shows that the highest velocity in narrow pore reaches 0.375 m/s. The air velocity within the dump shows that the velocity near the top and side surface is relatively high, which leads to the high oxygen concentration in that area. The coupled heat transfer and liquid flow process shows that the solution can act as an effective remover from the heap, dropping the highest temperature from 60 to 38 ℃. The reagent transfer coupled with solution flow is also analyzed. The results obtained allow us to obtain a better understanding of the fundamental physical phenomenon of the bioleaching process.

Selective separation of copper and cadmium from zinc solutions by low current density electrolysis

Copper and cadmium ions were selectively separated from zinc sulphate aqueous solution or zinc ammonia/ammonium sulphate aqueous solution by low current density electrolysis.It was shown that the concentration of cadmium ion in zinc sulphate solution decreased from 4.56 g/L to 0.18 g/L in an electrolysis time of 8.5 h,whilst it decreased from 5.16 g/L to lower than 0.005 g/L in zinc ammonia/ammonium sulphate aqueous solution.On the other hand,the deposition rate of copper was so low that it was difficult to separate copper and cadmium ions from the zinc ammonia/ammonium sulphate aqueous solution during electrolysis.But copper ion could be decreased to 0.002 g/L in this solution through solvent extraction by using kerosene diluted LIX984N as extractant.Therefore,it is favorable to recover cadmium ion from the zinc ammonia/ammonium sulphate solution by electrolysis after solvent extraction of copper.