AMERICANS ADVANCE IN POTASH PRODUCTION 39 
During 1917 brines supplied more than 60 per cent of the 
total potash production in the United States. 
h. Alunite. Alunite is essentially a basic sulphate of alumi- 
num and potassium containing ^ ^potash’ ^ (K 2 O) to the extent 
of about 11 per cent in the best varieties. At Marysvale, Utah, 
deposits have been developed on a large scale and a steady out- 
put of potassium sulphate has been maintained. At Sulphur, 
Nevada, are less well known deposits. 
The treatment, of alunite consists essentially of roasting the 
mineral, usually in rotary kilns of the cement-burning type, to 
drive off a part of the sulphur trioxide, convert the alumina 
into an insoluble form and the potash into a soluble sulphate. 
The last named salt is then extracted with water, separated from 
the insoluble residue, and recovered by evaporation. As no 
satisfactory method for disposing of the by-product alumina has 
yet been made, commercially, the industry is generally viewed as 
being of the ^Var-baby type,’’ but capable of stabilization 
through development of by-products when readjustment to peace 
conditions occurs. During 1917 the production amounted to 
2400 tons of potash, or about 8 per cent of the nation’s output. 
c. Cement kilns. At Riverside, California, a cement plant 
was compelled to abate its dust nuisance, and applied the Cot- 
trell process of precipitation, i.e., passing flue gases between 
electrically charged conductors maintained at high potential 
differences. The removal of 95 per cent of the solids was at- 
tained with relative ease, and to the surprise of the technical 
staff it was found that a large portion of this recovered dust con- 
sisted of water soluble potash, or of material that could readily 
be made water soluble. It is another illustration of a fact 
so often seen in industry — a plant is forced to correct a nuisance, 
and the improvements installed yield valuable products that 
formerly escaped, thus adding to the earning power of the plant. 
Modifications of this process were installed later for cement 
plants located at Hagerstown, Maryland, Salt Lake City, Utah, 
and other points, and success so far attained indicates that the 
adoption of this or similar systems will become general, espe- 
cially in the east. 
