[Proc. Koy. Soc. Victoria, 23 ^N.S.). Pt. II., 1911.] 



Aht. XXKVU.- Flofation of Minerals. 



By KENNETH A. MICKLE, 



Government Science Research Bursar, Melbourne University, and 

 Associate Working Men's College, Melbourne. 



[Read 8th December. 1910]. . 



Intpoduction. 



The various flotation concentration processes have in the last 

 few years attained much prominence in Australia, and parti- 

 cularly at Broken Hill, and promise to displace many of the 

 ordinary gravity processes in other parts. Very little literature 

 has appeared on this subject, and, with the exception of a few 

 scientific papers, most of it has been descriptive of the Avorking 

 of various processes, and not on the investigation of the general 

 underlying principles. The two usual explanations given as to 

 the cause of the flotation of minerals and metals in various 

 solutions are : — 



(1) That it is due to certain surface tension phenomena. 



(2) That it is due to the attachment of certain gases to the 



minerals which lift the particles to the surface. 



In a paper by J. Swinburne and G. Rudorf,! the authors ex- 

 plain why the sulphides rise in preference to the silicates, etc., 

 and why the bubbles remain attached to the sulphides, as due to 

 the combined effects of surface-tension, cohesion and adhesion. 

 They consider that the rise of temperature to near boiling point 

 is necessary for flotation for the same reason. 



Behaviour of Minerals and IVletais in Water. 



The object of the writer's work was to investigate the attach- 

 ment of gases to the different minerals and metals, and inciden- 

 tally to study the adhesion, or wetting of different minerals and 

 metals, and their subsequent flotation. 



1 The Physics of Ore Flotation. Chemical News, 29th December, 130.'j. 



