PART II 

 SULFATE OF POTASH, HIGH-GRADE 



It is customary to make sulfate of potash 

 from the double salt by adding sufficient 

 potassium chlorid to carry on the following 

 reaction : 



3KC1 + K2SO4 • MgS04 • 6H2O = 2K2SO4 + 

 KCl . MgCl2 . 6H2O. 



Procedure. — Calculate the amount of 

 potassium chlorid necessary to react with 

 the am.ount of double salt at hand, and weigh 

 out enuf muriate of potash to furnish this 

 amount of actual salt, allowing for impurity. 

 Heat the necessary amount of water to boil- 

 ing, dissolv the salt, filter off the dirt on a Witt 

 plate, and heat the filtrate until it is satu- 

 rated all as previously described under sul- 

 fate of potash-magnesia. 



Add the sulfate of potash-magnesia to 

 boiling water, using 100 cc. for every 80 grams 

 of salt, and put this mixture with the hot 

 saturated solution of the chlorid. Potas- 

 sium sulfate begins to separate at once and 

 continues to come out on cooling. After 

 standing 24 hours the salt may be filterd off 



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