浅谈试金炉法在铜米检验中的运用

文章主要介绍了改变现有含铜品位97.5%以上的铜米的检验模式,97.5%以上的铜米一般采用中频炉熔融法,在当前减员增效的背景下,人员的减少,产量的加大,给原料检验带来很大压力,不改变现有的铜米检验模式,不仅无法满足检验要求,中频炉设备负荷也重,作业人员的劳动强度也大,原料检验及时率无法得以保障,因此我们对于含铜品位大于97.5%的铜米改用试金炉法。通过试金炉法在铜米检验中的应用,大幅减少了中频炉的开炉炉次,降低了劳动强度,提高了原料检验及时率。

漆包线铜米介质摩擦脱膜精制的实验研究

为解决漆包线铜米漆膜的脱除问题,利用离心式摩擦装置,以铬铁矿砂作为摩擦介质,使铬铁矿砂与漆包线铜米进行充分摩擦,从而达到铜米脱膜精制的目的。根据铜米脱膜工艺,考察了铬铁矿砂粒径、离心式摩擦装置转子转速、铬铁矿砂与铜米混合比、摩擦循环次数等因素对铜米脱膜率的影响。结果表明,漆包线铜米脱膜最佳方案为:铬铁矿砂粒径为325μm、离心式摩擦装置转子的转速为2 700 r/min、铬铁矿砂与漆包线铜米混合比为1. 5∶1、摩擦循环次数为15次,在此最优条件下漆包线铜米脱膜率为96. 65%,满足了直接回收利用的条件。

漆包线铜米摩擦脱膜精制生产线设计研究

针对废漆包线低能耗、无害化精制的需求,提出使用摩擦碰撞方法去除铜米表面漆膜,设计并研制了漆包线铜米摩擦脱膜精制生产线,在保证生产线高程度自动化的基础上,要求设备平稳高效运行。使用长度为5~10 mm、直径为0. 26~0. 6 mm的漆包线铜米对样机进行测试,结果表明:铜米脱膜效率达96%以上,处理能力为10 t/h,平均能耗为1. 7 kW·h/t,满足设计要求。

浅谈碎料铜米检验风险防控的探索与实践

碎料铜米是炼铜的主要原料,主要由废五金类物料经过拆解分离、破碎、筛选、除尘等工艺流程后生成。碎料铜米在生产过程中带有少量泥砂、铁等非铜物料。目前,其所夹带泥砂量未有明确规定,检验过程中发现一些不法商贩使用与碎料铜米颜色相似的小砂石或铁米,不均匀埋藏在碎料铜米内谋利。贵冶原料部针对检验过程中存在的问题进行探讨分析,通过开展调查摸底、完善作业机制等方式,堵塞漏洞,有效降低了检验风险,维护了企业正当利益。

框式电解铜米冷压块生产阴极铜

铜米直接电解工艺是一种高铜回收率、高电流效率的废铜线材回收技术。针对直接电解铜米工艺的优缺点,提出并开展了使用阳极框(钛篮)电解铜米冷压块生产阴极铜的试验。结果表明,电解液温度升高时,电流效率升高但阴极铜质量下降;提高电解液循环速度时,较多铜粉颗粒被带至阴极表面,造成阴极铜质量下降;增加阴极电流密度,阳极产生大量铜粉颗粒并在框内聚集,对阴极铜质量产生一定的负面影响。在温度50℃、电解液循环速度14 L/h、阴极电流密度200 A/m^(2)的条件下直接电解48 h,可以得到表面致密的阴极铜产品,阴极电路效率为93.15%,阴极铜沉积速率为1.39 g/h。

铜米电解工业化试验研究

以铜米为原料在铜电解系统进行工业化应用试验,主要对铜米电解的生产过程控制、能耗、产品质量的研究情况进行了阐述。工业试验结果表明,铜米电解工艺可以产出接近A级铜品质的阴极铜,目前技术条件下,铜米直接电解生产阴极铜工艺成本高,仍需进行改进。

直读光谱仪测定回收铜米的铜及杂质含量

直读光谱仪作为一种便捷、快速的检测方法,但对杂质较多的回收铜米无法分析,本文通过对回收铜米进行初筛,吸附铁粉处理后,将样品铸锭,然后通过与国家标准中的分析方法进行对比,得出直读光谱仪能较好分析出回收铜米中的铅、锡含量,铜、锌、镍的含量有一定的偏差。因此可用直读光谱仪分析回收铜米中的铜及杂质含量,为合理利用回收铜米提供重要的参考价值。

一种进口铜米机的性能&故障剖析及改进创新

笔者公司引进了一套先进的丹麦进口的电线切粒、铜塑分离自动化设备。由于分离出来后的铜像米粒一样,因此称为铜米机。它是将拆解后的废弃电器电子产品所含的各类废杂线和报废的电缆线如何有效的回收再利用,将金属(铜)和非金属(塑料皮)有效的分离一直是废弃电器电子产品拆解项目后期的一个重要设备。技术先进的进口铜米机处理废线缆的效果很好,可以得到纯净的铜米和塑料。然而,精细化拆解工艺对原料、输送量、操作技能、风量、时间掌控等各参数都有严格的要求,如果条件缺一,加工出来的铜米纯度低,废塑料中残留铜较高,不仅降低铜回收率,还降低了废塑料的利用档次。进口铜米机吃进各种混杂原料,故障率高,设备损耗大。作为设备管理工程师,笔者从生产工艺入手,对性能掌握、特点分析与故障原理的剖析,进行一次全方位的隐患整改与技术创新。增加开机率,降低故障率,提高铜回收率及各种产物的质量。

电沉积铜钴纳米多层膜的机理研究

采用动电位扫描、循环伏安以及电化学交流阻抗等方法研究了铜钴纳米多层膜的电沉积机理．结果表明：在所研究的体系中，铜的沉积是扩散控制的可逆电极过程，而钴的沉积是首先形成Ｃｏ（ＯＨ）ａｄｓ的吸附中间产物，而后在电极上进一步还原为原子态．基于研究结果，提出了铜钴沉积的机制．

Preparation and tribological properties of surface modified Cu nanoparticles

Cu nanoparticles surface-modified by dioctylamine dithiocarbamate （DTC8） were synthesized using a two-phase extraction route. The size, morphology and structure of resultant surface-capped Cu nanoparticles （coded as DTC8-Cu） were analyzed by means of X-ray diffraction, transmission electron microscopy and infrared spectrometry. The tribological behavior of DTC8-Cu as an additive in liquid paraffin was evaluated with a four-ball machine, and the surface topography of the wear scar was also examined by means of scanning electron microscopy. Results show that Cu nanoparticles modified by DTC8 have a small particle size and a narrow size distribution. Besides, DTC8-Cu as an additive in liquid paraffin has excellent antiwear ability, due to the deposition of nano-Cu with low melting point on worn steel surface leading to the formation of a self-repairing protective layer thereon.

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.

A gradient nano/micro-structured surface layer on copper induced by severe plasticity roller burnishing

In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100μm in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries （LAGBs）. The coarse grains are refined into the few micro-sized grains by dislocation activities;deformation twinning was found to be the primary form for the formation of submicron grains;the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region.

Preparation of gradient wettability surface by anodization depositing copper hydroxide on copper surface

A facile route for preparation of gradient wettability surface on copper substrate with contact angle changing from 90.3°to4.2°was developed.The Cu（OH）2 nanoribbon arrays were electrochemically deposited on copper foil via a modified anodization technology,and the growth degree and density of the Cu（OH）2 arrays may be controlled varying with position along the substrate by slowly adding aqueous solution of KOH into the two-electrode cell of an anodization system to form the gradient surface.The prepared surface was water resistant and thermal stable,which could keep its gradient wetting property after being immersed in water bath at 100℃ for 10 h.The results of scanning electron microscopy（SEM）,X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS） demonstrate that the distribution of Cu（OH）2 nanoribbon arrays on copper surface are responsible for the gradient wettability.

Effects of reaction parameters on preparation of Cu nanoparticles via aqueous solution reduction method with NaBH_4

The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution.

Preparation of Cu nanoparticles with ascorbic acid by aqueous solution reduction method

Cu nanoparticles were prepared by reducing Cu2＋ ions with ascorbic acid through aqueous solution reduction method. The effects of solution pH and average size of Cu2O particles on the preparation of Cu nanoparticles were investigated. Cu particles were prepared at pH 3, 5 or 7, with the smallest Cu particles obtained at pH 7. However, Cu particles could not be prepared at pH 9 or 11. The average size of Cu2O particles can affect that of Cu particles. Larger Cu2O particles result in larger Cu particles. In addition, experiments were conducted to explore the reaction process by measuring the X-ray diffraction （XRD） patterns of specimens collected at different time points during the reaction. It was found that Cu（OH）2 was initially formed as a precursor, followed by the formation of Cu2O, which was finally reduced to Cu particles.

Adsorption behavior and adsorption mechanism of Cu(Ⅱ) ions on amino-functionalized magnetic nanoparticles

Amino-functionalized magnetic nanoparticle （NH2-MNP） were prepared by a sol-gel approach. The adsorption behavior of Cu（II） ions on NH2-MNP was discussed systematically by batch experiments. The effects of initial Cu（II） ions concentration, time, pH and temperature were investigated. In kinetic studies, the pseudo-second-order model was successfully employed, and the pseudo-first-order model substantiated that Cu（II） adsorption on NH2-MNP was a diffusion-based process. Langmuir model and Dubinin-Radushkevich model （R2〉0.99） were more corresponded with the adsorption isotherm data of Cu（II） ions than Freundlich model. The adsorption capacity was increased with the increment of temperature and pH. NH2-MNP remains excellent Cu（II） recoveries after reusing five adsorption and desorption cycles, making NH2-MNP a promising candidate for repetitively removing heavy metal ions from environmental water samples. According to the results obtained from adsorption activation energy and thermodynamic studies, it can be inferred that the main adsorption mechanism between absorbent and Cu（II） ions is ion exchange-surface complexation.

Synthesis of Cu2O/Ag Composite with Visible Light Photocatalytic Degradation Activity for in situ SERS Analysis

A multifunctional Cu2O/Ag micro-nanocomposite, which has the characteristics of high cat- alytic activities under the visible light and high surface-enhanced Raman scattering （SERS） activity, was fabricated via a facile method and employed for the in situ SERS monitoring of the photocatalytic degradation reaction of crystal violet. Through the variation of the AgNO3 concentration, Ag content on the Cu2O template can be controllably tuned, which has great influence on the SERS effect. The results indicate that Ag nanopartieles form on the Cu2O nanoframes to obtain the Cu2O/Ag nanoeomposite, which can act as an excellent bifunetional platform for in situ monitoring of photocatalytic degradation of organic pollutions by SERS.

Preparation and photocatalytic performance of Cu-doped TiO_2 nanoparticles

Cu-doped TiO2 nanoparticles with different doping contents from 0 to 2.0% （mole fraction） were synthesized through sol-gel method. X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the crystalline structure, chemical valence states and morphology of TiO2 nanoparticles. UV-Vis absorption spectrum was used to measure the optical absorption property of the samples. The photocatalytic performance of the samples was characterized by degrading 20 mg/L methyl orange under UV-Vis irradiation. The results show that the Cu-doped TiO2 nanoparticles exhibit a significant increase in photocatalytic performance over the pure TiO2 nanoparticles, and the TiO2 nanoparticles doped with 1.0% Cu show the best photocatalytic performance. The improvement in photocatalytic performance is attributed to the enhanced light adsorption in UV-Vis range and the decrease of the recombination rate of photoinduced electron-hole oair of the Cu-doped TiO2 nanoparticles.

Octahedral Cu_2O-modified TiO_2 nanotube arrays for efficient photocatalytic reduction of CO_2

A photocatalyst composed of TiO 2 nanotube arrays（TNTs） and octahedral Cu2 O nanoparticles was fabricated,and its performance in the photocatalytic reduction of CO2 under visible and simulated solar irradiation was studied. The average nanotube diameter and length was 100 nm and 5 μm,respectively. The different amount of octahedral Cu2 O modified TNTs were obtained by varying electrochemical deposition time. TNTs modified with an optimized amount of Cu2 O nanoparticles exhibited high efficiency in the photocatalysis,and the predominant hydrocarbon product was methane. The methane yield increased with increasing Cu2 O content of the catalyst up to a certain deposition time,and decreased with further increase in Cu2 O deposition time. Insufficient deposition time（5 min） resulted in a small amount of Cu2 O nanoparticles on the TNTs,leading to the disadvantage of harvesting light. However,excess deposition time（45 min） gave rise to entire TNT surface being most covered with Cu2 O nanoparticles with large sizes,inconvenient for the transport of photo-generated carriers. The highest methane yield under simulated solar and visible light irradiation was observed for the catalysts prepared at a Cu2 O deposition time of 15 and 30 min respectively. The morphology,crystallization,photoresponse and electrochemical properties of the catalyst were characterized to understand the mechanism of its high photocatalytic activity. The TNT structure provided abundant active sites for the adsorption of reactants,and promoted the transport of photogenerated carriers that improved charge separation. Modifying the TNTs with octahedral Cu2 O nanoparticles promoted light absorption,and prevented the hydrocarbon product from oxidation. These factors provided the Cu2O-modified TNT photocatalyst with high efficiency in the reduction of CO2,without requiring co-catalysts or sacrificial agents.