108 • Marine Minerals: Exploring Our New Ocean Frontier 



facture of calcium phosphates for animal feeds, den- 

 tifrices, food additives, and baking powder. Tech- 

 nical grades of phosphoric acid are used for cleaning 

 metals and lubricants. Food-grade phosphoric acid 

 is used as a preservative in processed foods. 



National Importance 



There is no substitute for phosphorus in agricul- 

 tural uses; however, its use in detergents has been 

 reduced by the substitution of other compounds to 

 reduce environmental damage in lakes and streams 

 partially caused by phosphorus enrichment (eutro- 

 phication). 



The United States leads the world in phosphate 

 rock production (table 3-14), but it is likely to be 

 challenged by Morocco as the world's largest pro- 

 ducer in future years. Domestic production sup- 

 plies nearly all of the phosphorus used in the United 

 States, except for a small amount of low-fluorine 

 phosphate rock imported from Mexico and the 

 Netherlands Antilles and high-quality phosphate 

 rock for liquid fertilizers from Togo. The United 

 States is currently a major exporter of phosphate 

 rock and phosphate chemicals but is facing in- 

 creased price competition from foreign sources (fig- 

 ure 3-7). Producers in the Middle East and North 

 Africa may continue to encroach on U.S. export 

 markets as new phosphorus fertilizer plants begin 

 operation and U.S. production continues to shut 

 down. 



Figure 3-7.— Major World Exporters of Phosphate Rock 

 Since 1975, With Projections to 1995 



Table 3-14.— World and U.S. Phosphate 

 Rock Production 



World Us^ ila 



Year production production production 



(million tons) (percent) 



1977 130 52 41 



1978 138 55 40 



1979 147 57 39 



1980 173 60 34 



1981 161 60 37 



1982 136 41 30 



1983 149 47 32 



1984 166 54 32 



1985 168 56 33 



1986 154 44 29 



SOURCE: Adapted from W. Stowasser and R. Fantel, "The Outlook for the United 

 Stales Phosphate Rock Industry and Its Place In the World," Society 

 of lillnlng Engineers of AIME. Society of Mining Engineers, Inc.. Reprint 

 85-116, 1985. 



The United States is currently a major exporter of phosphate 

 rock and phosphate chemicals but is facing increased price 

 competition from foreign sources, principally Morocco. 

 Domestic mines are shutting down, and some analysts be- 

 lieve that the U.S. industry is in danger of collapsing in the 

 future. 



SOURCE: W. Laver, "Phosphate Rock: Regional Supply and Changing Pattern 

 of World Trade," Transactions of the Institution of Ivlining and Metal- 

 lurgy, Sec. A— Mining Industry. July 1986, Transactions Vol. 95, p. A119. 



Domestic Resources and Reserves 



Phosphorus-rich deposits occur throughout the 

 world, but only a small proportion are of commer- 

 cial grade. Igneous phosphate rock (apatites) are 

 also commercially important in some parts of the 

 world. Commercial deposits in the United States 

 are all marine phosphorites that were formed un- 

 der warm, tropical conditions in shallow plateau 

 areas where upwelling water could collect. U.S. 

 phosphate rock reserves are estimated to be 1.3 bil- 

 lion tons at costs of less than $32 per ton.^^ The 

 reserve base is about 5.8 billion tons (at costs rang- 

 ing from less than $18 per ton to $91 per ton), with 

 total resources estimated at 6.9 billion tons. Over 

 70 percent of the U.S. reserve base is located in 

 Florida and North Carolina. There are also large 

 phosphate deposits in some Western States. 



Although the United States has potentially vast 

 inferred and hypothetical resources (7 billion tons 

 and 24 billion tons of phosphate rock respectively), 

 economic production thresholds for these resources 

 have not been calculated. Other deposits probably 



"W. Stowasser and R. Fantel, "The Outlook for the United States 

 Phosphate Rock Industry and its Place in the World," paper presented 

 at the SME-AIME Annual Meeting, New York, NY, Feb. 24-28, 

 1985, Society of Mining Engineers Reprint No. 85-116, p. 5. 



