SECTION IV. 



ELECTKO-METALLURGY. 



CHAPTER XIIL 



REFINING OF COPPER AND LEAD. 



Refining of Copper Calculation of the Work to be performed Various Fac- 

 tories Hamburg Refining Establishment Works of Messrs. Oeschger 

 and Mesdach M. Andre's Works at Frankfort M. Hilarion Roux's 

 Works at Marseilles The Elliott Metal Company's Works Oker 

 Foundry M. Gramme's Experiments M. Ed. Becquerel's Experiments 

 Thickness of the Deposition Work performed in the Refining of 

 Copper Absorbed Capital Cost Price Refining of Lead. 



AMONGST the various metals, the refining of which is obtained 

 by means of electricity, we shall mention copper and lead : 

 copper in various English and Continental factories, lead in the 

 Electro-metal Refining Co.'s works, of New York. 



COPPER REFINING. To obtain chemically pure copper, and 

 extract from raw coppers the often considerable quantities of 

 gold and silver which they contain, a bath of sulphate of copper 

 and thin copper cathodes, previously purified, is often used. 



The electric current must here, as in all applications of 

 electrolysis, supply the work required by the chemical decom- 

 position, and overcome the various resistances which oppose its 

 passage in the bath : metallic resistance, polarisation of elec- 

 trodes, &c. The electric energy must also effect the deposition 

 of the metallic atoms on the cathodes. 



In a bath of sulphate of copper, with copper anodes, the 

 sulphate is decomposed by the action of the current, and the 



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