Copper cathodes

Copper carbonates Copper cathode Copper cathodes... 

The New York Commodity Exchange (Comex) prices for cathode copper in January 1993, 1994, and 1994 were 2.218/kg, 1.844/kg, and 3.084/kg, respectively. The primary uses for copper metal and alloy are constmction, 42% electrical/electronic, 24% industrial machinery, 13% transportation equipment, 11% and consumer/general products, 10%. Copper compounds for use in agriculture and industry account for about 1% of total copper consumption. 

It will be instructive to consider briefly the methodology employed in the development of solvent extraction processes that have become operational. The development of the Bluebird Mine operation for the extraction of copper from dump leaching liquors by solvent extraction and the subsequent recovery of copper as either copper sulfate or cathode copper is used as an example. The initial investigations [11] included the following ... 

The filtrate from the jarosite process is now ready for copper electrowinning. In this step, copper is extracted from the sulfate electrolyte down to a concentration of 500 ppm. While leaving the nickel, tin, chrcme, cadmium and zinc in solution. Each batch produces 679 lb6 of cathode copper of 99% purity. 

The copper cylinder is the anode. The copper ring is the cathode. Copper ions and hydronium ions (H30+) are cations and nitrate and sulfate ions are anions. 

A current is passed through a solution of copper sulphate in a U-tube with copper electrodes in the opposite arms. At the cathode copper ions are reduced... 

These rate laws demonstrate that Cu(II) is not involved in the anodic partial reaction, whereas both HCHO and OH are involved in the cathodic copper deposition reaction. It is interesting to note that HCHO acts as an inhibitor of the partial cathodic reaction. The above rate laws suggest that the mechanisms are more complex than indicated by simple combination of two independent partial reactions. 

Typical anode and cathode analyses are shown in Table 5. Comparisons are made to the ASTM standard B 115-91, grade 1 cathode copper and European Standard EN1978 1998, Cu-CATH-1, which is the same as the London metal exchange (LME) grade A copper. 

The cathodes are grown for 5-14 days. The cathodes weigh 40-160 kg [20]. After being removed from the cell, the cathodes are thoroughly washed to remove the electrolyte that would otherwise contaminate the copper during melting. Two types of cathodes are commonly used. Cathode copper can be deposited on consumable thin copper starter sheets or on... 

Reactive metals in the copper anode, such as iron and zinc, are also oxidized at the anode and enter the solution as Fe and Zn + ions. They are not reduced at the cathode, however. The less electropositive metals, such as gold and silver, are not oxidized at the anode. Eventually, as the copper anode dissolves, these metals fall to the bottom of the cell. Thus, the net result of this electrolysis process is the transfer of copper from the anode to the cathode. Copper prepared this way has a purity greater than 99.5 percent (Figure 20.7). 

Electrodes anode (platinum, n-type silicon, conducting glass, stainless steel, gold/ glassy Carlson) cathode (copper) Electrolytes copper sulfate, acetonitrile + p-toluenesulfonoc acid (HTSO), lithium jjerchlorate, sodium perchlorate, sulfuric acid... 

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