464 



UNITED STATES MINERAL RESOURCES 



of gold mining. Part of the African resources are 

 probably paramarginal because of their remote 

 location. 



The total identified recoverable uranium re- 

 sources of countries listed in table 93 is about 1.6 

 million tons of UaOg, which is enough to supply the 

 estimated world demand until the late 1980's. 



Uranium resources in the U.S.S.R., China, and 

 some other Asiatic and eastern European nations 

 not listed in table 93 occur in deposits similar to 

 those found in North America. Data on identified 

 resources for these areas are not available. It is 

 known, however, that in the U.S.S.R., peneconcor- 

 dant uranium deposits occur in unspecified localities, 

 and uranium-bearing veins occur in the Ukrainian 

 region and elsewhere. 



Domestic hypothetical recoverable resources are 

 estimated to total about twice the identified recover- 

 able resources, or about 500,000 tons. If these re- 

 sources are found by continued exploration and are 

 mined, as expected, they will satisfy the estimated 

 domestic requirements only until the early 1990's. 

 After that, the domestic requirements, which will 

 gradually decrease if the fast-breeder reactors are 

 developed or will continue to increase if they are not, 

 will have to be satisfied by importing much of the 

 uranium needed or by mining much lower grade 

 uranium resources at a high unit cost. 



CONDITIONAL RESOURCES 



Peneconcordant sandstone deposits and vein de- 

 posits contain about 200,000 tons of UsOg classified 

 as identified paramarginal resources. These re- 

 sources, which are too lean to be mined at present 

 prices, are mostly adjacent to minable ore bodies 

 where they would be bypassed in mining, and sub- 

 ordinately in separate deposits. The material ad- 

 jacent to minable ore bodies would be very costly to 

 recover by conventional mining methods after mine 

 openings are abandoned and caved; perhaps, how- 

 ever, techniques of solution mining can be developed 

 to recover some of this uranium at moderate cost. 

 Alternately, a scheme to subsidize the extraction and 

 stockpiling of the low-grade material that is being 

 bypassed in current mining operations might be jus- 

 tifiable to conserve a resource that will be much 

 needed in the future. 



Other conditional resources consist of small 

 amounts of uranium concentrated in certain types of 

 rocks that are moderately abundant, and although 

 the amount of uranium in a single ton of these rocks 

 is small, the total amount of uranium contained in 

 them is indeed large. The uranium in such rocks 

 should be considered in appraising uranium re- 



sources, provided some of the factors limiting its 

 availability are appreciated. These factors are chiefly 

 price, technology, and byproduct status. 



Where the amount of uranium per ton of rock is 

 small, the recovered UsOg is necessarily expensive. 

 Such high-cost uranium must compete with possible 

 substitutes, including less expensive uranium from 

 domestic or foreign sources, thorium, and fossil 

 fuels. The abundance of coal, gas, and oil as alternate 

 fuels for the generation of electricity in the short 

 term and the possible increase in use of thorium in 

 nuclear reactors (see "Thorium") will effectively 

 limit the price that will be paid for uranium. Conse- 

 quently many domestic low-grade uranium deposits 

 will not be a source of uranium in abundance for 

 many decades to come. 



Whether much of the uranium in low-grade de- 

 posits becomes an available resource depends heavily 

 on developments in metallurgical and other tech- 

 nology. For some types of deposits the technology of 

 recovery has not yet been developed; from others 

 the uranium can be recovered but only at consider- 

 able expense. The development of new recovery 

 methods and the improvement in the efficiency of 

 others will determine how soon and how much of the 

 low-grade deposits become an available resource. 



The supply of uranium recovered as a byproduct 

 in the production of another commodity is deter- 

 mined by the amount of the prime commodity pro- 

 duced. It can be increased only as the markets for 

 the prime commodity expand. 



Factors such as the foregoing, which limit avail- 

 ability of conditional resources, must be borne in 

 mind in connection with the ensuing discussion of 

 the large low-grade uranium resources in the United 

 States. 



Marine phosphorites in the United States contain 

 large uranium resources. The Phosphoria Forma- 

 tion in Idaho and adjacent States is estimated to 

 contain identified paramarginal resources of about 

 700,000 short tons of UsOs in rock with an average 

 grade of not less than 0.012 percent UaOs (0.24 lb 

 UaOs per ton) and not less than 31 percent P2O5 (V. 

 E. McKelvey, written commun., 1951). Identified 

 paramarginal resources in the Bone Valley Forma- 

 tion in Florida are estimated to be about 300,000 

 short tons of UaOg in phosphate rock products of 

 about the same grade as in the Phosphoria (Alt- 

 schuler and others, 1956; J. B. Cathcart, written 

 commun., 1951). Additional marine phosphorites in 

 Idaho and North Carolina are estimated to contain 

 identified submarginal resources of about 5 million 

 short tons of UaOg in rock whose grade ranges from 

 about 0.006 to about 0.012 percent UsOs (0.12-0.24 



