Diatomaceous deposits of Fayum, Egypt: Characterization and evaluation for
industrial application
Mervat S. Hassan, Ibrahim A. Ibrahim and
Ismail S. Ismail
Central Metallurgic Research and Development Inst., Helwan, Cairo, Egypt |
The Holocene lacustrine diatomaceous earth of Fayum, SW of Cairo, is studied to define its
minerals, chemistry, petrography and physical properties.. Mineral processing
techniques were carried out using calcination at 550o C followed by acid
leaching to reduce levels of mineral impurities. The diatomite is of biogenic opal A, with
calcite as the main gangue mineral, quartz and clay minerals (smectite followed by
kaolinite in abundance and trace of illite) . The average content of silica in
diatomaceous earth is about 63%.
Positive correlation between CaO and CO2 indicates that Ca is mainly present as
calcite. Al2O3, Fe2O33, MgO and K2O
are mainly attributed to clay minerals. However, the physical properties of the
diatomaceous earth as filter- aids and filler for paint and plastic are poor due to the
general high level of impurities. Technologic properties of diatomaceous earth was
significantly improved due to upgrading of diatoms through mineral processing trials, to
be used as acid leaching
and calcination treatments.
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