1865.] MACFARLANE EXTRACTION OF COPPER. 219 



ON THE EXTRACTION OF COPPER FROM ITS ORES 

 IN THE HUMID WAY. 



By Thomas Macfarlane. 



In the last Report of the Geological Survey of Canada refer- 

 ence was made to the poor pyritous copper ores of the Eastern 

 Townships ; and with regard to the best method of utilizing them, 

 it was remarked as follows: " It is much to be desired that some 

 of the various methods which have been proposed for removing 

 the copper in a soluble form, could be applied to these ores."* 

 The importance of this question has by no means diminished, 

 since the publication of the report alluded to. The recent discov 

 ery, in the neighborhood of Lennoxville, of several very promising 

 beds of pyritiferous copper ore, the difficulty of concentrating 

 these by any of the usual mechanical processes of ore-dressing, 

 and the obstacles to the establishment of smelting-houses near to 

 the mines for the production of ingot copper, all combine to ren- 

 der this subject one of somewhat more than ordinary interest. 



The processes which have been from time to time proposed, and 

 put into practical operation, for the humid treatment of copper 

 ores are so numerous and diverse, that I shall not attempt to de- 

 scribe them minutely. I shall merely refer to some of the more 

 important among them, and especially to those which bear some 

 resemblance in principle to the method pursued in certain experi- 

 ments which I have performed on a small scale, with various 

 Canadian ores, in order to the extraction of the copper contained 

 in them. The results of these experiments having been very 

 satisfactory, I shall proceed to describe them, and, in conclusion, 

 refer to the manner in which the method of extraction founded 

 on them might be most advantageously carried out on a large scale. 



1. One of the oldest modes of producing copper in the wet way 

 is the precipitating it, by means of metallic iron, from the water 

 of mines, or that resulting from lixiviating old waste-heaps in 

 their neighborhood. These waters contain the copper in the form 

 of sulphates, derived doubtless from the oxidation of sulphuret 

 ores. This process is or was not long ago carried on at Schmollnitz 

 and Neusohl in Hungary, at Moldava in Croatia, in Anglesea, and 

 at Rammelsberg in the Lower Hartz. 



* Geology of Canada, page 736. 



