[Proc. Rot. Soc. Victoria, 24 (N.S.) Part II., 1911]. 



Art. XXII. — Flotation of Minerals. 

 Part 11. 



By KENNETH A. MICKLE 



(Government Science Eesearch Bursar, Melbourne Univ^ersity, and 

 Associate Working- Men's College, Melbourne.) 



[Read 4th December, 1911]. 



As stated in my paper read before this Society in December, 

 1910, the various flotation processes which are now being so 

 largely used for separating metallic sulphides from sulphide ores 

 depend upon differential gas and liquid attaching phenomena. 

 The sulphides are floated (on aqueous solutions) as a sort of scum 

 or froth by the agency of either gases alone or by gases assisted 

 by small proportions of various oily substances. The paper 

 referred to contained the results of investigation bearing on 

 these gases and liquid attaching phenomena, and the present 

 paper deals with a continuation of this work. 



The attachment of gases and liquids to solids 



and to each other with special reference 



to flotation processes. 



As oils and other substances of an oily nature are being exten- 

 sivety used in these processes, the behaviour of these substances 

 under varying conditions was investigated. 



In a paper^ by Lord Rayleigh it was shown that the presence 

 of small proportions of various contaminants in water very 

 materially affected its frothing properties. Pure water on being 

 vigorously agitated with air shows very little tendency to pro- 

 duce a froth. This tendency is very much increased by the 



1 "On the tension of water surfaces clean and contaminated." Phil. Mag. xxx., Nov. 

 1890, pp. 386-400. 



"Experiments with surface films." Phil. Mag. xxxiii., 1892, pp. 363-373. 



"On the theory of Surface Forces: Effects of slight contaminations." Phil. Mag. 

 xxxiii., pp. 468-471. 



"Investigations on Capillarity." Phil. Mag. xlviii., 1899, pp. 321-337. 



