Anodizing copper

The tank house is divided into commercial and stripper sections. In the latter, one-day deposits are prepared by electrorefining anode copper onto oiled copper, stainless steel, or titanium blanks. These copper sheets are stripped from the blanks and fabricated into starter sheets for the commercial sections as starting cathodes. After 9—15 days, depending on the tank house, hill-term cathodes are pulled and washed and either sent to the casting department or sold direcdy. 

The series system was used in the past as an alternative to the multiple system. In this system only anodes were charged and a potential was maintained between the ends of each cell so that copper dissolved from one anode was plated on the adjacent anode. After a sufficient period of time, all the original anode copper was replaced by a cathodic deposit and the impurities were either in the form of anode slime or in solution. The series system demanded highly uniform anodes, a requirement that was difficult to meet with horizontal equipment. 

Refining operations have two principal wastestreams, waste electrolyte and cathode and anode washwater. Spent electrolyte is normally recycled. A bleed stream is treated to reduce copper and impurity concentration. Varying degrees of treatment are necessary because of the differences in the anode copper. Anode impurities, including nickel, arsenic, and traces of antimony and bismuth, may be present in the effluent if the spent electrolyte bleed stream is discharged. Tables 3.14 and 3.15 present classical and toxic pollutant data for raw wastewater in this subcategory. 

A three-dimensional variation of the theme is offered by the oscillatory behaviour of anodic copper dissolution into a NaCl/KSCN electrolyte mixture.27 This is a complex process involving solid states CuSCN (pKsp = 14.32) and Cu20 or CuOH (pKsp = 14), and CuCl (pKsp = 5.92), and ionic species Cu+, CuCl22, CuCl3, and Cl. Among other plausible schemes,... 

As an illustration, the oscillatory behaviour of anodic copper dissolution discussed in Section III.3, with P elements shown in Table 5, is chosen. The eigenvalue theorem yields three relationships (k= 1,2,3) ... 

At the impure Cu anode, copper is oxidized along with more easily oxidized metallic impurities such as zinc and iron. Less easily oxidized impurities such as silver, gold, and platinum fall to the bottom of the cell as anode mud, which is reprocessed to recover the precious metals. At the pure Cu cathode, Cu2+ ions are reduced to pure copper metal, but the less easily reduced metal ions (Zn2+, Fe2+, and so forth) remain in the solution. 

The viologens are alkyl derivatives of the 4,4 -dipyridylium dication. The one- or two-electron reduction leads to a radical cation or a diamagnetic product, respectively [95]. This type of redox reaction has a good reversibility. In the phthalocyanines (PCs) and other 4-chelates, the nitrogen is also a component of the ring system. Donor-type Li" " insertion compounds of metal-free phthalocyanines were formed reversibly in LiC104/PC with up to six cations [96]. At the anode, copper phthalo-cyanine (CuPC) inserted reversibly y — 0.42 CIO4 anions/mol [97]. For copper tetraphenylporphyrin, y = 0.65 was found [98] (cf. Table 4). Composites of these... 

A study of seawater by stripping analysis reveals an anodic copper peak having a height of 0.13 /xA when deposition is carried out at —0.5 V. However, deposition at —1.0 V yields a larger peak of 0.31... 

When electric current flows between the electrodes of a cell, an electrochemical process occurs. Taking the classical example of two copper electrodes and a solution of copper sulphate in v/ater, we knox / that at the anode, copper oxidizes and the positively charged ions pass into solution. In the ideal case, at the same time and with the same amount (since the current is the same) at the cathode the positively charged copper ions are reduced upon the electrode. The amount of material dissolved or deposited is directly proportional to the amount of electricity which has flowed. 

Anode (copper plate) Cathode (constantan wire)... 

To collect current from the segmented anodes, copper flat wire is run to each anode segment and is electrically connected to the fabric with stainless steel staples. Installation of insulated copper flat wire is described as follows and depicted in Figure 11.7. The goal here is to create good, waterproof electrical contacts between the carbon... 

Copper and other sulfide ores with gold are concentrated by flotation, when gold concentrates with copper. In the final step, in which anode copper is dissolved in an electrolytic process (and copper is precipitated on the cathode) gold is not anodically dissolved but stays with the silver in the slime. This is melted to a raw silver, which is used as an anode in a new electrolytic process in an electrolyte containing nitric acid. Silver is dissolved but gold, and platinum, stay in a new anode sludge, from which gold is extracted. 

Blister Melted blister copper Poling reduces the oxygen The anode copper, with... 

Anode copper, produced in the metallurgical process, is used for electrolytic refining. The anodes are placed in an electrolyte containing copper sulfate and sulfuric acid. Between the anodes, thin start plates made of pure copper are inserted as cathodes. In the process the anodes are dissolved and the cathode plates grow by copper precipitation. After electrolysis for 10 days the weight of the cathodes has increased to 145 kg and their copper content is 99.95% or more. This copper is delivered as refined copper. 

Nodulation was resolved by taking the copper dissolution out of the module and replacing the standard anode with an inert or insoluble anode. Copper dissolution or oxidation was achieved by different means, such as the use of rectification, the use of ozone, or the dissolution of copper oxide. 

Schematic of grain boundary region in a 2XXX alloy. Precipitation of the very-high-copper-content precipitates on the boundary causes a copper-depleted zone on either side of the boundary. The difference in the electrochemical potentials of the copper-depleted zone and the copper-rich matrix form a strong galvanic cell with a potential difference of about 0.12 V. Furthermore, the anodic copper-depleted zone is small in area compared with the area of the cathodic grain matrix, resulting in a high driving force for rapid intergranular corrosion. (Courtesy of Alcoa Technical Center, Edward L. Colvin.)...

A method of measuring the TOW has been developed by Sereda and correlated with the corrosion rates encountered in the atmosphere [13]. The moisture sensing elements in this sensor are manufactured by plating and selective etching of thin films of appropriate anode (copper) and cathode (gold) materials in an interlaced pattern on a thin nonconductive substrate (Fig. 9.23). When moisture condenses on the sensor it activates the cell, producing a small voltage (0 to 100 mV) across a 10 Q resistor. 

LOOPING SULFIDE OXIDATION PROCESS FOR ANODE COPPER PRODUCTION... 

Kroll Institute for Extractive Metallurgy, Colorado School of Mines, Golden, CO 80401 Keywords Copper Smelting, Anode Copper, Flash Smelting, Looping Sulfide Oxidation ... 

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