Impurity control and removal in copper tankhouse operations

During copper smelting, most of the undesirable impurities such as Pb, Sb, Bi, and As are only partially removed by oxidation. When white metal and blister copper are in equilibrium, these impurities are distributed mainly into the copper phase, from which their removal is difficult. When copper dissolves during electrorefining in a copper tankhouse, these impurities are continuously released from the anodes either as insoluble phases (slimes), which fall to the bottom of the cell, or as dissolved species in the electrolyte, the transfer of which to the cathode must be inhibited. This article presents impurity control methods in copper tankhouse operations with traditional and newly developed processes. It also summarizes the technologies demonstrated for removal of impurities from electrolyte that prevent them from being recycled in the copper smelting and refining circuit. For more information, contact Shijie Wang, Phelps Dodge Refining Corporation, 850 Hawkins Blvd., El Paso, TX 79915; (915) 775-8836; fax(915) 775-8352; e-mail swang@phelpsdodge.com.     

Anodic behaviour of copper,cobalt and nickel silicide electrodes

The electrochemical corrosion behaviour of Cu, Co and Ni silicides was studied using potentiostatic quasi-steady-state techniques. Sulphate and chloride electrolytes were employed. In separate experiments, the fraction of total current i_tota1, causing oxygen evolution, i₀₂, and corrosion, i_corr was determined. The effect of annealing did not appear to give rise to major changes of behaviour. Details of metallographic structures both before and after corrosion are given. The importance of structure in its effect on the corrosion rate is considered.     

Structural and magnetic properties of iron,cobalt and nickel nanoparticles

This study focuses on the synthesis and characterization of iron, cobalt and nickel nanoparticles through sol–gel method and heat-treating technique in argon atmosphere. The structure, morphology and magnetic properties of the as-synthesized products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) magnetometer. XRD studies indicated that the as-prepared products were iron, cobalt and nickel with well crystallized bcc, fcc and fcc structure, respectively. TEM observations showed that the as-synthesized products composed of spherical shape with size around 2, 2 and 2 nm for iron, cobalt and nickel, respectively. Magnetization results revealed that the as-obtained products showed superparamagnetic character at 300 K. The magnetic anisotropy of the products is much higher than that of bulk owing to the nanostructure.     

镍基合金电解加要渣泥中镍和钴的回收

根据镍基合金电解加工渣泥的组成和热力学分析,用水洗-浸出-水争沉淀工艺处理这种渣泥,试验结果表明：氯化钠、硝酸钠和部分铬盐等可溶性化合物可以从渣泥中洗出;继而的硫酸浸出过程中,可将洗后渣泥中的镍、钴和铬浸出,而钨和钼留在浸出渣中,在浸出过程中,镍和钴的浸出率达98%,浸出液中的铬可通过水解沉淀法以氢氧化铬的形态除去,铬的脱除率达94.44%。     

Recovering iron,manganese, copper,cobalt, and high-purity nickel from sea nodules

Many studies have investigated methods of recovering valuable metals from sea nodules. Recently, a research group in Japan developed a smelting and chlorine process after investigating a variety of existing processes and comparing their respective efficiencies with the same nodules. The best results were obtained by combining pyrometallurgical and hydrometallurgical treatments, which enabled the efficient recovery of manganese, nickel, copper, and cobalt. High-purity nickel can be also produced through further solvent extraction.     

Solvent extractants for nickel and cobalt: New opportunities in aqueous processing

The last two decades have witnessed unprecedented growth in the development and implementation of solvent extraction technology in the extractive metallurgy of nickel and cobalt. Solvent extraction is proving to be a powerful tool, opening new opportunities for simpler, more cost-efficient and environmentally sound metal refining processes. This article provides an overview of some of the latest developments regarding the solvent extractants. For more information, contact Indje Mihaylov, Inco Technical Services Limited, 2060 Flavelle Blvd., Mississauga, Ontario, L5K 1Z9 Canada; (905) 403-7910; fax (905) 403-2401; e-mail imihaylov@inco.com.     

Separation of nickel, cobalt and copper by solvent extraction with P204

Separation of nickel, cobalt and copper by solvent extraction with P204@钱东@王开毅@潘春跃@唐有根@蔡春林@蒋金枝~~Project ( 99JJY2 0 0 10 )supportedbytheNaturalScienceFoundationofHunanProvince     

Electropolishing of nickel and cobalt in deep eutectic solvents

Electropolishing is a common method for decreasing surface roughness and removing surface irregularities. In this paper the electropolishing of nickel and cobalt are successfully demonstrated in a deep eutectic solvent, comprising a 2:1 molar mixture of ethylene glycol and choline chloride. Voltammetric and electrochemical impedance studies were used to characterise the polishing mechanism and show that film formation occurs prior to polishing. Scanning electron microscopy and atomic force microscopy were used to characterise the morphology before and after polishing and 3D optical microscopy was used in-situ to observe film formation during polishing. This study shows that the impact of film formation and subsequently mass transport are responsible for electropolishing of both metals in the choline chloride-based ionic liquid.     

Preferential sulfation of nickel and cobalt in lateritic ores

Pilot plant operations have confirmed the validity of a process for the recovery of nickel and cobalt from the ores of laterite deposits, the world’s largest known reserves of these metals.     

Burrs—Analysis, control and removal

Increasing demands on function and performance call for burr-free workpiece edges after machining. Since deburring is a costly and non-value-added operation, the understanding and control of burr formation is a research topic with high relevance to industrial applications. Following a review of burr classifications along with the corresponding measurement technologies, burr formation mechanisms in machining are described. Deburring and burr control are two possible ways to deal with burrs. For both, an insight into current research results are presented. Finally, a number of case studies on burr formation, control and deburring along with their economic implications are presented.     

含纳米金刚石粉镍钴基复合镀层的研究

通过对爆轰制备的纳米金刚石粉进行去除杂质,亲水处理,制备出分散稳定的含纳米金刚石粉的镀液。利用这个镀液制备出含纳米金刚石粉的Ni—Co复合电镀层,并研究了镀液中分散不同含量纳米金刚石粉对制备镀层的表面形貌,晶粒尺寸的影响,镀液中纳米金刚石粉含量从2g／L增加到6g／L,镀层的晶粒尺寸减小近一半。纳米金刚石粉对晶粒的细化程度和镀层中含有的纳米金刚石粉的含量有很大关系。镀层的显微硬度与镀液中分散的纳米金刚石粉的含量并不成线性关系,镀层的显微硬度最大可达601．53HV。团聚的纳米金刚石粉导致镀层晶粒的异常长大。     

Indentation size effect in nickel and cobalt laser clad coatings

In this work it is reported a comparative study of the indentation response at different length scales in nickel and cobalt samples produced by laser cladding. The indentation tests were carried out in the load range 57 μN to 2 N. Both in Ni and Co, the indentation hardness increases as the indentation dimension decreases from the micrometer to the nanometer range. It is shown that the experimental results can be accurately described by an analytical function, whose terms account for the contributions of dislocation density and surface free energy to the material's hardness. Although the good relation between the model and the experimental points is not a fully evidence, it strongly suggests that, as the hardness scale decreases, the increase of dislocation density and the increase of the surface-to-volume ratio of the plastically deformed region are the most important causes for the observed indentation size effect.     

The effect of cobalt and nickel on transformation in TiRh

The transformations in TiRh and the effect of replacement of rhodium in TiRh by cobalt and nickel have been studied. TiRh undergoes two structural transformations which are of first order, exhibit thermoelastic properties and persist in the Ti---Rh---Co and Ti---Rh---Ni ternary alloys. Stabilization of the high temperature phase of TiRh of B2 type crystal structure down to room temperature can be achieved by substitution of cobalt at about 15 at.% and of nickel at about 20 at%. The TiCo---TiRh and TiNi---TiRh sections of the corresponding ternary systems are found to be quasi-binary.     

硫酸氢铵硫酸化焙烧法红土镍矿提取镍钴

针对传统硫酸化焙烧红土镍矿能耗高、设备腐蚀大等缺点,提出硫酸氢铵焙烧循环工艺。以菲律宾红土镍矿为原料,对焙烧剂添加量、焙烧温度和焙烧时间等工艺参数及焙烧机理进行研究。结果表明:焙烧温度300℃、焙烧时间90 min的条件下,Ni、Co、Mn、Mg、Fe的提取率分别为95%、96%、92%、57%、79%,硫酸氢铵具有良好的硫酸化能力。该工艺具有效率高、能耗低、环境友好等特点,对低品位红土镍矿的开发利用具有重要意义。     

锈蚀法提取预还原红土镍矿中镍和钴

以国外某红土镍矿经氯化离析法预处理后的还原矿为原料,对锈蚀法处理预还原红土镍矿工艺进行研究,系统考察酸料质量比、空气流量、锈蚀温度、锈蚀时间、搅拌速率以及固液比(固体质量与液体体积比,mg/mL)对铁、镍和钴浸出率的影响。结果表明:在酸料质量比0.10,空气流量1 L/min、锈蚀温度80℃、锈蚀时间8 h、搅拌速率300 r/min和固液比1:10的条件下,镍和钴的浸出率分别达到90.9%和80.2%,铁的浸出率仅为9.9%,实现了铁与镍和钴的分离。