UNITED STATES. DEPARTMENT OF AGRICULTURE 
| BULLETIN No. 312 
' Contribution from the Bureau of Soils 
MILTON WHITNEY, Chief 
Washington, D. C. PROFESSIONAL PAPER November 5, 1915 
PHOSPHATE ROCK AND METHODS 
PROPOSED FOR ITS UTILIZATION 
AS A FERTILIZER 
By 
WILLIAM H. WAGGAMAN and WILLIAM H. FRY 
CONTENTS 
Page 
PMUYOHUMCHONY 5) G05) ie Jee elie ss) 1 | Processes in which the Phosphorus or 
Phosphate Deposits of the United States 3 Phosphoric Acid is Volatilized . . . 15 
Forms in which Phosphoric Acid is Ap-_ . Processes Dealing with the Production 
PEO tO SOUS. aie) se Soe 8 of Two or More Fertilizer Elements . 17 
Processes for Treating Phosphate Rock f Processes Dealing with the Production 
in the Manufacture of Phosphoric Acid; of Available Phosphates by Electrolysis 18 
and Phosphatic Fertilizers . . ... - §* Processes for the Enrichment of Phos- 
Processes for the Production of Phos- — DhateS) e ayia sehen all outa mt peneee 19 
phoric Acid or Soluble Phosphates by Mechanical Treatment of Phosphates . 20 
' Combined Heating and Acid Treatment 12 | Miscellaneous Processes for the Produc- 
Double Decomposition by Means of an tion of Available Phosphates . . .. 26 
Alkali, an Alkali Salt, or Alkaline Earth. 12 | Appendix: Classified Tabular List of ’ 
Processes to be Used in Connection Patented Processes .... 2.2. 21 
with the Iron and Steel Industries . . 14 . 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1915 
