First Mining Drc-Zambia March -April 2020 digital edition First Mining Drc-Zambia March - April 2020 digital | Page 24

FEATURE
Further, structural data comprising
of structural identifications and their
respective orientations is measured by
means of Acoustic Televiewer, a down
the hole geophysical method. There are
instances where the upper sections of
the rock mass is highly fractured making
the drilling and identification of strata
more complex.
through highly fractured rock which
required the grouting of holes and the
use of specifically designed drilling
muds. An Acoustic Televiewer was used
to ensure that the direction of the holes
did not deviate more than 2º from the
required angle of -70º.
According to Nkosi Nene, Chief Rock
Engineer at Foskor, “Our experience
working with Geomech Africa has been
a good and a professional one. Our
working relationship and collaborative
efforts and engagement has yielded
good results.”
The holes have had to be grouted in
places to allow the drill to pass through
larger cracks and specific drilling muds
have been used in the production
process to help prevent the collapse
of unstable strata into the borehole
and the escape of essential cooling
and lubricating drilling muds into open
cracks. The correct drilling muds were
identified through a combination of
experience and trial and error.
Drilling supervisor, Kiewiet Mahlangu
has been in the exploration drilling
division of Geomechanics for 14 years
and using his knowledge, he tested
various scenarios and their impact on
the formations as the drill advanced, until
the correct balance was found. The final
solution involved Aus plug, Bentonite
and CR650.
The contract lasted 3 months and
was completed on time.
According to Nkosi Nene, Chief Rock
Engineer at Foskor, “Our experience
working with Geomech Africa has been a
good and a professional one. Our working
relationship and collaborative efforts and
engagement has yielded good results
and progress on the project and we are
pleased thus far.”
Facebook summary
Geomech Africa recently completed a
3-month geotechnical survey for Foskor
Mining Division in the Limpopo Province
of South Africa. The objective of the
project was to identify the continuity of
the rock. The data obtained will be used
to help optimise Foskor’s North and
South pits.
The orientated holes, which ranged
from 300m to 500m deep, were drilled
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