THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



JUNE 1856. 



LI I. Contributions to the Metallurgy of Copper. 

 By Ai' DibK*. 



■ ! !, " .1- ,l-j . 



THE following investigation was made in the metallurgical 

 laboratory of the jMuseum of Practical Geology, at the 

 request of Dr. Percy, with the special object of ascertaining 

 the causes of the characteristic properties of ordinary "tough 

 pitch copper" and of ''overpoled copperf." 



Before detailing the experiments, it may be well to describe 

 very briefly that part of the smelting process termed refining, iu 

 which the copper is obtained in these conditions. An impure 

 copper, the product of previous operations, is kept melted in the 

 oxidizing atmosphere of a reverberatory furnace for a consider- 

 able time. The products are copper containing suboxide in 

 solution, and a slag rich in suboxide of copper. The object of 

 this process is to remove as completely as possible by oxidation, 

 the last traces of various metals and the sulphur left in the cop- 

 per after the previous treatment. Copper thus saturated with 

 suboxide is known as dry copper. The slag is then skimmed off, 

 and anthracite thrown upon the surface of the melted copper. 

 By this means the suboxide is reduced, and the action is com- 

 pleted by plunging one end of a pole of green wood under the 

 surface of the melted metal. The gases produced by the decom- 

 position of the wood produce a kind of ebullition, which causes 

 every portion of the metal to be brought more rapidly and 

 thoroughly in contact with the anthracite than would otherwise 



* Communicated by the Author. 



t For a detailed description of the refining of copper see Phil. Mag. 

 S. 4. vol. V. p. 40fi. 



Phil. Mag. S. 4. Vol. 11. No. 74. June 185G. 2 E 



