Making Millions Out of Bubbles 



Huge profits, undreamed of yesterday, are now 

 obtained from the dump pile of low-grade ores 



By George Merriman Oaks 



Managing Editor of the Popular Science Monthly 



MILLIONS are at stake in lawsuits 

 brought about by infringement of 

 the froth flotation patents. Clear- 

 ly, they must be very important patents. 

 In truth, they are 

 the basis of a great 

 industrial achieve- 

 ment. In one mine 

 alone the flotation 

 method increased 

 the daily output of 

 zinc by 200,000 

 pounds; in another, 

 the daily increase 

 in copper was 

 120,000 pounds. 

 The adoption of 

 froth flotation by 

 the five leading 

 porphyry mines of 

 the United States 

 would mean a 

 yearly saving of 

 $17,000,000. 



What is froth 

 flotation? Nothing 

 but the industrial 

 utilization of bub- 

 bles. Who would 

 believe that bub- 

 bles could be 

 turned to money — ■ 



Why Doesn't He Sink? 



This water-spider Hoats, not because he is so lisht, 

 but because of surface tension. With a little 

 care, a needle can be floated in the same way 



yes, millions? And to think of ap- 

 plying such ethereal objects as bub- 

 bles, whose greatest achievement has 

 always been to grow a little bigger and 

 then burst, to an 

 industry like min- 

 ing! 



It seems as 

 though Nature's 

 most precious gifts 

 are often hedged 

 about with thorns 

 so prickly that 

 ceaseless labor is 

 necessary to obtain 

 them. We find cop- 

 per combined with 

 sulphur as copper 

 sulphide. Further- 

 more, the sulphide 

 is shaken up with 

 all sorts of worth- 

 less mineral mat- 

 ter, such as sand 

 and limestone, un- 

 til it seems hope- 

 lessly hidden from 

 man's reach. The 

 same is true of the 

 other base metals, 

 zinc and lead. 

 The useless matter 



U/et 



Not 

 wet 



Wet 



Floating Bodies Are Attracted or Repelled Depending on Their Wetness 



Attraction of two bodies not wet by a 

 lic|uid. In this instance, the pressure 

 is tlie sainf at all |K)inls indicated by 

 the dotted line, namely, that of the 

 outside atmosphere. Pressure is also 

 that of the atmosphere in the air 

 space between the two bodies; but 

 tlic water pressure on each side (in- 

 dicated by the arrows) is greater, 

 pushing the two bodies toward each 

 other. Applies to sulphides in water 



Repulsion of two bodies, only one of 

 whigh is wet by a liciuid. Pressure on 

 left side of wet body is less than that 

 of atmosphere whicli-acts on its rifiht 

 side, pusniuK it away from the other 

 body. Pressure 'on left ••■ide of body 

 not wet by liquid is ureater (below 

 surface of li(|uiil) than that of atmos- 

 phere on riKht side. Hence the i)res- 

 Bure of the linuid pushes the body 

 not wet away from the other Viody 



82 



Attraction of two bodies wet by a 

 liciuid. Pressure is the same at all 

 points indicated by dotted lino, 

 namely, that of the outside atmos- 

 phere. Pressure is less in the liquid 

 between the bodies and above the 

 dotted line. Therefore, the atmos- 

 pheric pressure outside pushes the 

 bodies toward each other. The liquid 

 rises between the bodies due to the 

 principle of capillary atlraetion 



