Pollution Abatement in a Copper Wire Mill

2 Pollution Abatement in a Copper Wire Mill 1.9.2.1 The Significance 

The metal must also be washed free of pickling solution. The resulting rinsewaters contain metal salts. Because of the low concentration of these contaminants the rinses are difficult to treat economically. 

In the case of the production of copper wire, additional complications are present because of the chemical reduction of cupric oxide to a cuprous oxide coating, which cannot be removed by sulfuric acid. This coating has normally been treated by a secondary pickle of chromic acid-sulfuric acid, chromic acid-ammonium bifluoride mixtures, or by nitric acid. All of these techniques produce additional pollutants. Each of the three to four drawing steps required to produce fine copper wire from copper rod requires these pickling and rinse steps. 

The waste from such an operation, if treated by conventional precipitation techniques without an examination of the manufacturing process itself, would impose a severe cost on the manufacturing operation and produce large amounts of sludge for disposal. 

Comparison of Effluent Quality before and after Process Modification 

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