weight, and dried kelp contains the equivalent of about 25 per cent potassium chloride or 16 per cent 

 potassium oxide (K2O equivalent).^' Only the giant kelp is present in sufficient quantity to be a 

 potential source for potash. 



Sea water contains about 380 parts per million potassium (Table 6, Mineral Resources and Ocean 

 Mining) making this element one of the more abundant constituents. Although this may be regarded as a 

 virtually limitless potential resource, the extremely large high grade land-based potash resources make it 

 very unlikely that it wiU be economically feasible to recover potash from sea water for a long time. 



The sedimentary rocks in the Gulf Coast shelves are also a possible source of potash because of the 

 presence of large salt deposits; however, none is known for certain. 



McKelvey^* points out that saline deposits at shallow depths in areas of upwelling are another 

 possible source of potash, although it has not yet been found offshore. 



RARE-EARTH ELEMENTS 



Uses. The uses of rare-earth elements, as corhpounds, metals, and alloys, may be grouped in the 

 following categories hsted by order of importance: the glass industry; carbons for arc hghting; metals 

 and alloys; and miscellaneous apphcations. 



Present levels of utilization of rare-earth oxide equivalents in tons. 



World, exclusive of United States (1966 production) 6,500 



United States (1966 demand) 5,700 



U.S. production must be withheld to avoid disclosing individual confidential data. 



Ranges of demand projections to the year 2000. 



Prospective supplies and prices. Until recently, domestic production of the rare-earth elements was 

 obtained from monazite, largely imported. The bastnaesite deposit at Mountain Pass, CaUfornia, assures 

 a domestic supply of most of the rare-earth elements through year 2000 and many years beyond at 

 average prices approximating those currently in effect. Prices can show violent surges if large-scale uses 

 for individual rare-earth elements develop without concomitant increasing demand for the other 14 

 members of the group. Some low-grade resources, such as those in phosphate rock, would come into 

 production if prices showed an inclination to stiffen appreciably. 



Thorium is a by-product of monazite processing and a strong demand for it could create a surplus of 

 rare-earth elements with a consequent lowering of rare-earth prices. 



37 



Ocean Science and Engineering, Inc. report. 



V. E. McKelvey and Livingston Chase, "Selecting Areas Favorable for Subsea Prospecting," in Exploiting the 

 Ocean (Washington, D.C.: Marine Technology Society, 1966). 



VII-150 



