PROCEEDING? OF SECTION B. 353 



8.— NOTES ON THE BEHAVIOUR AND ELIMINATION OF 

 CERTAIN IMPURITIES IN COPPER SMELTING AND 

 REFINING. 



By G. C. McMUSTEY, A.R.S.M., A.B.C.Sc. 



The presence of small amounts of impurities in copper has often a 

 marked effect on the character of the metal, rendering it more suitable 

 for some purposes than for others. 



In the metallurgy of iron and steel the influence of these small 

 amounts of other elements is well known, and their presence or absence 

 entirely alters the character of the product produced. But with copper 

 very much remains to be done in the direction of ascertaining the 

 action of these impurities. 



The cause of this branch of the metallurgy of copper being so 

 neglected is largely due to the fact that the average consumer of the 

 red metal often knows nothing of the reason why one brand of copper 

 in the market is more suitable for his work than other makes. It is 

 well known, for instance, that a copper containing a fair amount of 

 arsenic is more suitable for such pm*poses as rolling-plates for the fire 

 boxes of locomotives, or for the manufacture of commercial copper wire, 

 but such copper could never be used for electrical work, and would also 

 be unsuitable for making the best alloys of copper required for fine 

 castings or rolling. 



I remember the result of a test of some electrolytic copper wire, 

 as to its suitability or otherwise for telegraphic purposes. This wire 

 passed well all the tests except one — in fact was higher than asked for 

 in most cases ; but I think the cause of failure in the one particular 

 might be accounted for by the fact that the sample contained about 

 ■n03 per cent, of bismuth. This impurity does not affect (when only 

 present in small quantities) the electrical conductivity of the copper, 

 b)ut is apt to interfere with some of the mechanical tests which are re- 

 quired to be complied with. 



The remarks I propose to make are taken from actual results 

 obtained during the years I have been engaged in copper smelting and 

 refining operations, and in many instances the impurities were not 

 present in the original copper ore treated, but became part of the 

 ■" matte " or " regulus " produced after the first smelting had taken 

 place, and so had to be reckoned with, and means taken to eliminate 

 them. Several of the impurities came from ores of gold and silver, 

 which were smelted ^\'ith copper and finally separated from this metal 

 by electrolytic refininR. 



I wish to acknowledge my indebtedness to my predecessor, T. C. 

 Cloud, Esq., A.R.S.M., &c., who was manager of the Wallaroo Smelting 

 Works before myself, as several of the results were obtained during the 

 time I was his assistant. 



Antimony. — This metal is one which no copper metallurgist has 

 any love for, it being practically impossible to entirely eliminate, even 

 z 



