14 BULLETIlSr 415, U. S. DEPAETMENT OF AGKICULTURE. 



SUMMARY. 



Considerable interest is being evinced in processes for the recovery 

 of potash and other products from alnnite. This mineral is a hy- 

 drous sulphate of potash and alumina. It occurs in important 

 deposits both north and southwest of Marysvale, Utah. 



Difficulty in effecting a complete separation of the potash after 

 the ignition of the mineral has been experienced both in the labora- 

 tory and in factory practice; and since the material must be regarded 

 as a relatively low-grade potash carrier, cheapness and efficiency in 

 the extraction of the potash are essential to its successful commer- 

 cial development. 



Eleven samples of Hght-colored alunite from the undeveloped, but 

 readily accessible, area north of Marysvale were ignited at different 

 temperatures and the residues subsequently leached with water. A 

 temperature between 750° and 800° C. was found to be best for the 

 complete extraction of the potash with the minimum amount of 

 water. Temperatures above 800° C. caused a fixation of the potash, 

 particularly where the samples contained much siUoa. 



An experiment to test the influence of fineness of grinding on the 

 subsequent extraction of potash from alunite showed that nothing 

 is to be gained by grinding the material finer than 60 mesh. 



Since practically all of the constituents of high-grade- alunite have 

 their market in the East, it is suggested that it would prove more 

 economical to ship the mineral East, taking advantage of the lower 

 freight rate on raw material, than to manufacture the finished prod- 

 ucts near the mines. The freight charges, even then, however, are 

 so great as to leave a very narrow margin of profit on the products 

 in normal times. 



ADDITIONAL COPIES 



OF THIS PUBLICATION MAY BE PROCURED FROM 



THE SUPERINTENDENT OF DOCUMENTS 



GOVERNMENT PRINTING OFFICE 



■WASHINGTON, D. C. 



AT 



5 CENTS PER COPY 

 A 



