Abstract :
The United States production of phosphate in 1980 accounted for 40 percent of the world production; however, the ability to sustain such a product ion level throughout the remainder of the century is Questionable. In light of anticipated depletion of onshore resources coupled with increasing onshore land-use conflicts, the value of further assessment of marine phosphorite mining is becoming increasingly more apparent. The marine phosphorites are principally composed of carbonate fluorapatite, and occur as crusts, plates, nodules, muds, and sands at depths generally less than 1,000 meters. Techniques for exploration and mining systems are available that consider the environmental and geological factors. Marine phosphorites in potentially economic quantities occur in a number of regions in the United States concinental margins. Major Known deposits are located off Southern California, off the coasts of Florida, Georgia, and South Carolina; off North Carolina in the vicinity of Onslow Bay, and the northwest portion of the Blake Plateau. They may also be located in other areas under U.S. jurisdiction or control, Such as the Hawaiian archipelago and the Trust Territories. These phosphorite deposits which are economically attractive should be exploitable with current technology and mining methods.
