Electrorefining of copper

In the electrorefining of copper, copper(I) sulfate in the AN-H20-H2S04 solution is electrolyzed using a coarse copper electrode as anode and a pure copper electrode as cathode. The reaction at the anode is Cu° —> Cu+, while that at the cathode is Cu+ —> Cu°. Compared to the conventional process which uses aqueous acidic solutions of copper(II) sulfate, this method is advantageous in that the quantity of electricity is one-half and the electric power is also small. Moreover, the low quality AN used in this method is available at low price and in large quantity as a by-product of chemical industries. 

Electrochemical Reduction of C02 in Non-Aqueous Solvents 321 Use of Acetonitrile in Electrowinning and Electrorefining of Copper 323... 

FIGURE 18.19 Electrorefining of copper metal, (a) Alternating slabs of impure copper and pure copper serve as the electrodes in electrolytic cells for the refining of copper, (b) Copper is transferred through the CuS04 solution from the impure Cu anode to the pure Cu cathode. More easily oxidized impurities (Zn, Fe) remain in solution as cations, but noble metal impurities (Ag, Au, Pt) are not oxidized and collect as anode mud. 

Fig. 6 Current density-cell voltage dependence for the electrorefining of copper.

The Electrorefining of Copper The most common copper ore is chalcopyrite, CuFeS2, a mixed sulfide of FeS and CuS. Most remaining deposits contain less than 0.5% Cu by mass. To win this small amount of copper from the ore... 

Figure 21.27 The electrorefining of copper. A, Copper is refined electrolytically, using impure slabs of copper as anodes and sheets of pure copper as cathodes. The Cu ions released from the anode are reduced to Cu metal and plate out at the cathode. The anode mud contains valuable metal by-products. B, A small section of an industrial facility for electrorefining copper.

The studies of the use of the ion exchanger Metalfix Chelamine of tetraethylenepentamine ligands (1,4,7,10,13 - pentaazatridecane) in the process of recovery, concentration and separation of platinum metal ions, gold and their accompanying elements from the environmental samples, anodic sludges from the electrorefining of copper ores, spent car exhaust gas catalysts, etc. [93-98]. 

Analyze We are asked to predict whether nickel can be oxidized at the anode and reduced at the cathode during the electrorefining of copper. 

Zinc is another common impurity in copper. Using standard reduction potentials, determine whether zinc will accumulate in the anode sludge or in the electrol) c solution during the electrorefining of copper. 

Figure 6.19.10 Aqueous electrorefining of copper. Also shown are the potential-current relationships for a more electrochemically noble impurity (Ag) and a less noble impurity (Ni). Adapted from Hamann and Vielstich (2005).

Electrodissolution — Electrodissolution is the electrochemical dissolution of a material to soluble species. It can be regarded as the reversal of electrodeposition. While most metals dissolve anodically, oxide films usually dissolve cathodically. In an electrochemical cell one can have electro deposition on one electrode (typically the cathode) and electro dissolution at the other (typically the anode). Prominent examples for combined electrodissolution/electrodeposition processes are the electrorefining of copper or metal plating involving the utilization of soluble anodes. A high-precision technical application of electrodissolution is electrochem-... 

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