Mineral Resources Potential - Geothermal Resources

IS0 M i d Resources Potentld uf Ethiopia
composed of apatite, ihenite and magnetite has the following
compositions and mums: 3.59% PzOs, 6.04% TiOz, 0.09%V205
and 2 1,87% total iron. The nm-surface, Iow-grade igneous
phosphates from Bikilal have been evaluated on their suitability for
upgrading through siezing and magnetic separation (Abera, 1 988;
Abera et a!., 1994). Apatite concentrates up to 36% P2O5 were
produced using simple processing techniques. However, the
recovery rate was low at only 40-5 8% (Abem, et al., 1994).
4.16 ~y~surn, anhydrite
Occurrence
Gypsum is a very common mineral, is thick and extensive
evaporitic beds in association with other sedimentary rocks. The
largest deposits known occur in strata from the Permian age.
Gypsum is deposited in lake yd sea water, as well as in hot
springs, from volcanic vapors, and sulfate solutions in veins.
Hydrothermal anhydrite in veins is commonly hydrated to gypsum
by groundwater in near surface exposures. It is often associated
with the minerals halite and sulfur. Because the gypsum from the
quarries of the Montmartre district of Paris has long furnished
burnt gypsum used for various purposes, this material has been
called plaster of Paris (McVey, 1989).
Production
Commercial quantities of gypsum are found in Germany, Italy,
England, in British Columbia, Manitoba, Ontario, Nova Scotia and
Newfoundland in Canada, and in New York, Michigan, Iowa,
Kansas, Arizona, New Mexico, Colomdo, Utah and Nevada in the
United States. There is also a large mine located at Plaster City,
California in Imperial County (McVey, 1989).