106 



CHEMICAL MANUEES. 



other. The mixer works continuously ; no stop is made except in 

 case of a breakdown. When one " mixing " is finished the sides of 

 the mixer are rapidly dusted with a little phosphate to neutralize- 



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r ^1 ■lii, ; - ~ — . 



Mim\\mmimAAmmmmm]sm- 



iii!»iiiiiii iiiimiifii niiiiiini'i ii'iiiii iiiiriiiiiii nin|i|iiii' liiilinm 



Fig. 21. — Mixer installed above the Superphosphate " Den ". 



any free acid left there which might corrode the metal. The work- 

 ing of the mixer requires three men ; the first takes charge of the 

 machine, the second superintends the measuring and running in of 

 the acid, the third brings the sacks of phosphate. The charging of 



