THE RECOVERY OF POTASH FROM ALUNITE. 13 



of the water) have a commercial value in the east, where better 

 facilities for their separation are to be had and whither the mineral 

 may be shipped at the lower rates usually prevailing for raw materials. 

 Probably factories in the Middle West are most favorably situated 

 for the handhng of the raw material. 



The ignition of the mineral could probably be very economically 

 carried on at one of the sulphuric-acid plants run in connection with 

 the fertihzer factories. The oxides of sulphur evolved during the 

 burning of ore could be turned into the Glover tower of the acid plant 

 and the yield of acid substantially increased at very httle cost. 

 Moreover, the potassium sulphate produced could be consumed on 

 the spot in the manufacture of mixed fertihzers. 



In Table IV are given the quantities and value (under normal condi- 

 tions) of the ingredients of alunite (90 per cent pure) and in Table V 

 the estimated cost of separating and preparing these products for the 

 market. 



Table IV. — Amount and value {under normal conditions) of products contained in 1 ton 



(2,000 pounds) of alunite {90 per cent pure). 



Dollars. 



K2O, 198 pounds, at4 cents per pound 7. 92 



H0SO4 (50° B.), 1,647 pounds, at |6 per ton^ 3. 44 



AigOs, 666pounds,atS7perton2 2.33 



Total value 13. 69 



Table V. — Estimated cost of mining, shipping, and extracting the products of alunite. 



I Dollars. 



Mining per ton 1. 00 



Freight to Alississippi River, per ton ^ 9. 00 



Cost of grinding, per ton 30 



Cost of ignition, per ton 50 



Cost of acid recovery, per ton 1. 00 



Cost of leaching and recovering potash 1. 00 



Total cost 12. 80 



From the figures given in Tables IV and V it is evident that in 

 normal times the margin of profit on the products of alunite would 

 be extremely narrow because of the long freight haul unless a lower 

 freight rate should be estabhshed for the raw material. Under pres- 

 ent conditions, however, the prices of metaUio aluminum, sulphuric 

 acid, and potash salts have advanced so enormously that the imme- 

 diate exploitation of the western alunite should prove both practic- 

 able and profitable. 



J Only three-fourths of the SO3 of alunite is volatilized on ignition. 



2 The value of the AI2O3 Is based on that in bauxite. The average bauxite contains CO per cent AI2O3 

 and is valued normally at $4.7.5 x>er long ton. 



» No commodity rate yet exists for alunite, but if a rate ia established it has been estimated that it prob- 

 ably would be in the neighborhood of %'.) per ton. 



