铜粉对连铸连轧铜杆性能影响浅析

随着国内电力、电子行业的迅猛发展,电线、电缆等行业发展壮大,作为主要原材料的铜杆已经成为目前市场主要消耗的铜加工产品。铜杆品质已作为铜杆生产商之间市场竞争的主要筹码。由于铜杆多需要继续拉丝深加工,因此,下游客户对铜杆拉丝性能也有了更为严格的要求。拉丝过程中产生的铜粉也成为了铜杆生产商和铜杆下游用户关注的焦点。文章将分析铜粉产生的原因,寻找降低拉丝铜粉的针对性措施。     

分散剂对由矿浆电解铜粉分散性能的影响

超细铜粉在导电料浆等领域具有广泛的用途,利用矿浆电解直接将铜精矿制备成超细铜粉是矿浆电解新的应用领域.实验采用铜精矿为原料,通过机械活化预处理,直接在矿浆电解过程中添加分散剂进行表面改性处理,可直接在矿浆电解槽中将铜精矿制备成粒度100%小于3.5 μm的超细铜粉.研究了动物胶、硅酸钠和六偏磷酸钠对超细铜粉粒度和形貌的影响.结果表明:矿浆电解过程中添加适量的分散剂有利于提高超细铜粉的分散性能,分散剂有一最佳用量,不同种类的分散剂其最佳用量不一样,在最佳用量范围内,随着分散剂用量的增加,铜粉粒度不断下降,比表面积不断上升;但当分散剂用量超过最佳值时,铜粉反而产生团聚现象.铜粉的分散性能和分散剂的种类有关,动物胶、硅酸钠和六偏磷酸钠相比,六偏磷酸钠的分散效果较好.     

稀土对电沉积法制备泡沫铜化学预镀工艺的影响

通过实验手段，研究了稀土对电沉积法制备泡沫铜化学预镀工艺的影响。结果表明，在化学镀液中加入稀土元素，镀液稳定，使用次数多，产生的铜粉较少，且镀层厚平整。     

日本制成超细铜粉

日本制成超细铜粉日本一家公司采用一种独特的加氢加热气化金属氯化物而以粉状制取金属的蒸发法制成超细铜粉，生产的铜粉呈完整的环形，颗粒大小均匀，并可随意调整。该公司采用这种新工艺生产了直径只有０．１～１μｍ的超细铜粉，将其用于电子工业，可使网板印刷法刻制...     

纳米铜粉的制备研究

本文研究了化学还原法制各纳米铜粉的方法。本实验以次磷酸钠为制备纳米铜粉的还原剂。实验得出其较佳工艺条件： pH值在1．5—2．0之间，温度60℃左右，高速搅拌，反应时间15—20min，硫酸铜溶液中的Cu^ 2被还原为紫红色粉末。对所得产品进行XRD谱图分析，证实紫红色粉末为铜粉，但其在空气中不稳定，极易被氧化为Cu2O。通过扫描电镜图片观察，所得铜粉一次粒径约为十个纳米，但团聚体为数百个纳米的颗粒。     

阴离子膜电解制备铜粉的研究

介绍了阴离子膜体系电解制备铜粉的特点。研究了电流密度、铜离子浓度、阴极液酸度和阴极液中其它阳离子对电流效率、成粉率和成粉电流效率的影响，给出了阴离子膜体系电解制备铜粉较佳工艺技术条件。     

从镀镍废挂架直接电解生产铜粉

本文介绍了从镀镍废挂架直接电解生产铜粉的技术工艺，从热力学和动力学角度分析了其冶金原理，确定了电解制取铜粉的最佳生产工艺操作条件。     

高毛细效率纯铜毛细芯制备工艺研究

为了有效提升纯铜毛细芯的毛细效率和传热极限，利用粉末冶金方法制备高毛细效率毛细芯。以氧化亚铜粉末为铜源在不同温度还原制成铜粉，研究了还原温度对铜粉性能的影响。铜粉经模压、烧结制备出了毛细芯，研究了不同还原铜粉、生坯孔隙率、烧结温度等因素对毛细芯孔隙率、最大孔径和渗透率等多孔性能的影响，并观察了还原铜粉和毛细芯的表面显微形貌。结果表明，600～850℃还原温度区间内，随着还原温度提高，铜粉粒度增大，粒度分布宽化，松装密度随之增加；在相同烧结条件下，毛细芯烧结后的最大孔径相比生坯有所增大，毛细芯的最大孔径及孔隙率随着还原铜粉粒度增大和生坯孔隙率(40%～55%区间内)增加而增加，在孔隙率和最大孔径同步增大的耦合作用下渗透率相应增大；600～800℃区间内，提高烧结温度导致烧结毛细芯的最大孔径增大、渗透率增加而孔隙率减小；采用600℃还原所制备的<28μm铜粉在700℃烧结，获得最大孔径2.4μm，孔隙率51.5%，渗透率1.353×10^-13 m²的高毛细效率纯铜毛细芯。     

低成本电解制取铜粉新工艺

低成本电解制取铜粉新工艺上海大学材料科学院金属材料系研究生郭海亮在陈世琯教授与周邦娜副教授的精心指导下，结合当前工业生产中酸性硫酸钢水溶液电解制取铜粉时，存在的电耗大，产品质量不稳定，成本高等问题，对工艺参数、添加剂、粉末形成条件、钝化剂等进行了系统...     

铜电解废液—胆矾—铜粉—金属铜币

从铜电解废液中制取铜粉比生产胆矾,经济效益可提高几倍。而用铜粉进一步生产金属铜币,价值又可成十倍地增加。本文介绍了铜粉与铜币的生产工艺。     

锰粉代替锌粉去除硫酸锌溶液中铜镉研究

湿法炼锌过程中,溶液净化过程中需要进行除铜镉操作,传统除铜镉方法以锌粉为还原剂去除铜镉,锌粉耗量高,产出铜镉渣品位较低.为了降低除铜镉工序物料消耗,提高铜镉渣品位,研究了用锰粉替代锌粉进行硫酸锌溶液中铜镉的去除,研究结果表明,金属锰粉代替锌粉除铜镉工艺可行.除铜镉速率及去除效果均优于电炉锌粉,同时也达到了降低成本的效果...     

电工用铜线坯对漆包线耐压性能影响

通过漆包线耐压检测、金相显微观察、铜粉检测等检测手段,研究了漆包线耐压性能的影响规律。通过对漆包线耐压击穿点的形貌分析、类型统计,影响耐压性能主要是漆瘤、针孔、划伤,对铜粉含量、铜粉形态等进行研究,研究表明随着铜粉含量的增加击穿不良率越高,铜粉含量控制在 4mg 以下且成细小颗粒状能有效改善耐压性能,为漆包线生产提供了指导。     

电化学方法回收废旧电路板制备高纯超细铜粉

采用电化学方法回收废旧电路板中的铜,以十二烷基硫酸钠(SDS)和吐温-80(Tween-80)为添加剂,制备高纯超细铜粉,通过四因素(电流密度、温度、SDS质量浓度和Tw-80浓度)三水平的正交实验优化工艺条件。采用等离子发射光谱分析仪、扫描电镜、X射线衍射和傅立叶红外光谱分析等对铜粉的形貌与结构进行观察与分析,并对铜粉的抗氧化性能进行测试。结果表明,最优工艺条件为:在p H值为0.5,温度为20℃的点解液中,脉冲占空比0.8、周期10 ms,电流密度100 m A/cm~2,电解液中SDS的质量浓度为2 g/L,Tween-80的体积分数为2%。制备的铜粉纯度为99.92%、平均粒度为4.9μm,其微观形貌为紧密堆积的圆形颗粒,平均晶粒尺寸为33 nm,抗氧化性能良好,接近400℃温度下才开始氧化。     

矿浆电解法制备超细铜粉

以铜精矿为原料,通过活化预处理,采用超声场辅助矿浆电解的方法直接利用铜精矿制备成平均粒度小于10μm的超细铜粉。研究了超细铜粉的粒度分布、形貌及比表面积特性。超细铜粉经油酸和丙酮的表面改性处理后,抗氧化性能得到提高。     

Direct electrolytic refining of end-of-life industrial copper waste scraps for production of high purity copper powder

The end-of-life electric cables from both domestic and industrial sources offer an attractive resource of copper metal. In addition, copper wastes generated during fabrication of copper components remains another valuable source of recyclable copper. This work reports a simple, cost-effective and eco-friendly direct electrolytic refining using waste electrical copper wire scrap and copper plate rejects for producing the value added high purity copper powder. Suitable anode support system was applied in which compressed wire scrap or copper plate rejects were held to make anode for electrolytic cell. Electrolysis parameters like current density, acid concentration and copper ion concentration were varied to arrive at optimum condition. Results showed the energy consumption of 1.44 kW h/kg at 89% current efficiency for producing the copper powder, that consisted of >80% of–325 mesh size particles, from waste copper wire anodes. However, slightly lower energy consumption of 1.32 kW h/kg at 91% current efficiency was observed during production of copper powder from copper fabrication rejects. The copper powder thus produced was characterised by chemical analysis, XRD and optical microscope to examine the purity and morphology etc. and found suitable for powder metallurgical applications. Present investigations have established the potential utilisation of copper waste wire scrap and copper plate rejects for the production of value added high purity copper powder.     

基体铜的粒度对铜基粉末冶金摩擦材料性能的影响

采用粒度为270、150、106和75μm的气雾化纯铜粉作为基体,通过粉末冶金热压烧结的方式,制备铜基摩擦材料.研究基体铜的粒度对材料的物理力学性能、材料组织和摩擦性能的影响.采用MM-3 000摩擦磨损试验机测试3 000~7 000 r/min转速条件下材料的摩擦性能,结果表明:铜粉粒度从270μm减小到75μm时,材料的流动性变差,压坯密度降低,材料的硬度呈减小趋势,从18.5 HBW降到14.0 HBW.但是铜粉粒度为106μm时,硬度反而增加为2.0 HBW.随着转速的升高,摩擦系数呈先增加后减小的趋势,粒度为106μm的试样摩擦系数比较稳定,摩擦系数变化从0.336到0.348,磨损率也最低,在7 000 r/min初速度下仅为47 mg.     

铜基粉末冶金双锥同步器同步环的加工及优化

以-200目电解铜粉和雾化细黄铜粉为原料, 利用喷撒烧结设备、拉伸成锥设备及模具, 研究了铜基粉末冶金双锥同步器同步环的撒粉烧结和拉伸成锥工艺。结果表明, 铜基粉末冶金摩擦材料的孔隙率保持在30%左右, 且孔隙呈细微和均匀分布; 摩擦材料层的平均动摩擦系数为0.081, 静摩擦系数为0.146, 磨耗率为8.70×10-9 cm3/J; 该材料在随钢芯板冷拉伸成锥形时不掉渣, 厚薄均匀, 锥度、圆度及尺寸变化很小, 其原料配方和拉伸成锥工艺可适用与大批量生产。     

Hydrogen reduction of copper bleed solution from an Indian copper smelter for producing high purity copper powders

A bench scale investigation on the hydrogen reduction of a highly acidic copper bleed solution to produce high purity copper powder is discussed in this paper. A titanium lined autoclave of 1 L capacity was used for this study. The parameters optimized on the bench scale were validated by performing hydrogen reduction of copper in a larger autoclave. Effect of various parameters viz., time of reduction, temperature of reduction, pressure variation, iron dose, volume of copper solution etc. were studied. Experiments were performed with synthetic and actual solution obtained from a copper plant. A 99% copper powder recovery is achieved by hydrogen reduction at a pressure of about 2400 kPa, reaction temperature of 453 K, stirring speed of 400 rpm for a reaction time of 2 h. The fine copper powder thus obtained had a good metallic lustre. Kinetics of reduction of copper was examined by drawing samples at different times and analyzing the percent copper reduction. The copper depleted solution was further purified with respect to the residual copper and can be processed for the recovery of nickel powder by hydrogen reduction.Properties of the copper powder obtained from the large-scale experiments from actual plant and synthetic solutions have been evaluated for powder metallurgical applications. The raw and annealed copper powders obtained from the synthetic copper solution were found to have an apparent density of 3.50 g/cm³, flow rate 35.6 g/min, hydrogen loss 0.2%, purity 99.8% and green density of 8.6 g/ cm³ while the powder from actual plant solution was found to have an apparent density of 3.59 g/ cm³, flow rate 46.0 g/min, hydrogen loss 0.6%, purity 99.4% and green density 8.6 g/ cm³. Thus, the copper powder produced by hydrogen reduction was found suitable for the application.     

基体Cu粉粒度对制备镍包铜粉包覆效果的影响

在预先制备出不同粒度的Cu粉上采用化学沉积法制备超细镍包覆铜复合粉体,用扫描电子显微镜、能谱仪研究镍包覆铜粉末的微观形貌及成分,考察基体Cu粉的粒度对镍包覆效果的影响.结果表明:基体Cu粉的粒度越细镍包覆效果越好,但同时会降低粉体的分散性.     

OBSERVATIONS ON THE SINTERING OF COMPACTSFROM A MIXTURE OF IRON AND COPPER POWDERS

Abstract

Three grades of iron powder-an atomized steel powder, a sponge iron powder reduced from magnetite with carbon, and a powder reduced from mill scale with hydrogen were mixed with 3% of copper powder and pressed into compacts. The diametral dimensional changes of the compacts during sintering below and above the melting point of copper were measured, their microstructures examined, and both related to the characteristics of the powders, particularly their specific surface. During sintering below the melting point of copper, compacts of all three powders shrank. Micrographic examination showed that the copper is transported by solid-state diffusion along the surfacesand grain boundaries of the iron powder particles. During sintering above the melting point of copper, compacts of the atomized and the MH-100 sponge iron powders grew while those of the hydrogen reduced mill-scale powder shrank. This phenomenon is related to the different mode of penetration of liquid copper in the compacts from the three powders, observed in the microstructures of the compacts.