1.9 Principal Thorium-containing Minerals

Heretofore, most of the world’s thorium has come from monazite in beach sands where coproduction of rare earths, titanium, and zirconium has defrayed much of the cost of extracting thorium. Recent increased interest in thorium as an alternative feed material for nuclear power systems has led to more extensive search for thorium deposits and to interest in other thorium minerals that could be produced if the demand for thorium (and its price) increased. Table 6.12 lists the principal thorium-containing minerals and gives their nominal composition and examples of where they have been found.

1.10 World Thorium Resources

Table 6.13 gives the thorium resources of the non-Communist world as estimated by the Organization for Economic Cooperation and Development [01] in December 1977. The definitions of the two resource categories are the same as for Table 5.17. The production cost of these thorium resources was not stated in [01], but was probably $15/lb Th02, from similar statistics cited by Nininger and Bowie [N3].

Since 1975, renewed interest in thorium as source material for production of 233U has led to extensive prospecting for thorium, discovery of numerous potentially commercial deposits and substantial increase in U. S. resource estimates over those listed in Table 6.13.