NATURAL RADIOACTIVITY, MINERALOGY AND RADIOLOGICAL HAZARD ASSESSMENT OF FELDSPARS FROM ESH EL MELAHA RANGE, EASTERN DESERT, EGYPT

The feldspars at Esh El Melaha range, North Eastern Desert of Egypt, are excavated from
Gabal Homret Al Gerigab and Gabal Esh areas. They are separated from the stream sediments, which
characterized by granitic composition and contain high amounts of feldspar phenocrysts. The two feldspar
occurrences were sampled from their quarry stockpiles and the activity concentrations of U, Th, Ra and
K were determined by gamma ray spectrometry. The abundance of these radionuclides in Gabal Homret
Al Gerigab are higher than those in Gabal Esh area, except K that is higher in all feldspar samples.
However, for all feldspar samples, the radiometrical measurements are higher the recommended levels of
these radionuclides.
The mineralogical characterizations of the investigated feldspars indicated that zircon, monazite and
to a lesser extent fluorite are the main radioactive accessory minerals. The contents of these minerals in a
given sample were affecting directly on the level of radioactivity. The elevated concentrations of natural
radionuclides in Gabal Homret Al Gerigab area are connected with the presence of higher quantities of
the aforementioned accessory minerals.
In order to assess the radiological impact from the investigated feldspars, parameters such as radium
equivalent activities, external hazard index and absorbed dose rate were determined. The results indicated
that the use of the studied feldspars as raw materials for ceramic industry is unsafe to the public due to their
elevated radioactivity. The studied feldspars require intensive purification from the radioactive accessory
minerals by the application of suitable technologies of magnetic separation and chemical processing.