UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 415 i 



Contribution from the Bureau of Soils. 

 MILTON WHITNEY, Chief. 



^S^J^^^U 



Washington, D. C. 



PROFESSIONAL PAPER. 



October 10, 1916 



THE RECOVERY OF POTASH FROM ALUNITE. 



By TV. H. Waggaman, Scientist in Fertilizer Investigations, and J. A. Cullen, Analyst. 



CONTENTS. 



Introduction 1 



Composition and properties of alunite 2 



Geological occurrence and origin 2 



Location, extent, and accessibility of the 



Utah deposits 3 



The production of alum from alunite 5 



The production of potash from alunite 6 



Temperature of ignition and its effect on the 



subsequent leaching of alunite 9 



Influence of fine grinding on the extraction 



of potash from alunite 11 



Economic considerations 12 



Summary 14 



INTRODUCTION. ' 



The scarcity of potassium salts in this country due to disturbed 

 conditions abroad, coupled with the discovery of extensive deposits 

 of high-grade alunite ^ in central Utah, have caused considerable 

 development work in this field and greatly stimulated interest in 

 processes for the extraction of potash from this mineral. 



Alunite, even when fairly pure, must be regarded as a relatively 

 low-grade potash carrier, and since the more important deposits 

 occur in a region far from the f ertihzer market, any process employed 

 for the extraction of potash from the mineral must be not only highly 

 efficient but extremely cheap. Indeed, under normal conditions it 

 is unhkely that any method wOl prove commercially practicable for 

 exploiting the Western alunites which does not produce in addition 

 to a soluble potash salt, somfi other salable product. 



Experience in the handling of low-grade ores, or in operations for 

 the extraction of a moderate-priced product from any raw material, 

 has sho\vn that strict attention to details and a knowledge of their 

 importance will often mean the difference between profit and loss. 



It was with a view to determining the importance of such details 

 in the recovery of potash from alunite that the work described in 

 this paper was undertaken. 



J Butler and Gale, Bull. 511, U. 8. Geological Survey (1912). LoughJiii, O. F., Bull. 620-K, U. S. Geo- 

 logical Survey (1915). 



54C27»— Bull. 4ir, 10 



