UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 415 
Contribution from the Bureau of Soils. 
MILTON WHITNEY, Chief. 
Washington, D. C. 
PROFESSIONAL PAPER. 
October 10, 1916 
THE RECOVERY OF POTASH FROM ALUNITE. 
By W. H. Waggaman, Scientist in Fertilizer Investigations, andj. A. Cullen, Analyst. 
CONTENTS. 
Introduction 
Composition and properties of alunite 
Geological occurrence and origin 
Location, extent, and accessibility of the 
Utah deposits 
The production of alum from alunite 
The production of potash from alunite 
Page. 
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 1 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 fertilizer 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 unlikely that any method will prove commercially practicable for 
exploiting the Western alunites which does not produce in addition 
to a soluble potash salt, some other salable product. 
Experience in the handling of low-grade ores, or in operations for 
the extraction of a moderates-priced product from any raw material, 
has shown 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. 
i Butler and Gale, Bull. 511, U. S. Geological Survey (1912). Loughlin, G. F., Bull. 620-K, U. S. Geo- 
logical Survey (1915). 
54627°— Bull. 415 16 
