MINERALS IN BEACH SANDS
OF NORTHWEST PALAWAN, PHILIPPINES
Gil A. Alapan
Radioactive heavy minerals are found in
beach sands of northwest Palawan as dark
bands, laminations and streaks in an
otherwise white silica sand. The heavy
minerals were derived from granitic
intrusives underlying Mt. Capoas, Erawan
Point and Bay Peak. These occur as minor
accessory minerals in the granite.
Monazite, rutile anatase, allanite,
zircon and sphene were identified in the
detritus. Speciments of granite studied
show only zircon and allanite. The
radioactive elements associated with the
heavy minerals are uranium and thorium.
In addition high concentrations of rare
earth minerals were found in a number of
Uranium occur in greater amounts in
monazite; lesser in sphene and zircon
and much less in allanite. Uranium as U3O8
ranges from 0.0037% to 0.76%, Thorium
content is greatest in monazite and
allanite, less in sphene and zircon.
Thorium as ThO2 ranges from
0.17% to 9.65% Rare earths ranges from
3.3% to 64.85%.
Test by the International Atomic Energy
Agency in Vienna Austria indicate that
the U3O8 contained
in the heavy minerals are not
recoverable by current leaching methods.
For the present, the U3O8
can be viewed as by-product of the
extraction for thorium.
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