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PRODUCT News
February 2017
MODERN MINING
43
The United Cement Company of Nigeria
(UNICEM) recently successfully com-
missioned its new cement plant 2 at
Mfamosing in Cross River State, Nigeria.
The cement plant at Mfamosing has
been fully operational since February 2009
and is equipped with the latest technol-
ogy. With a capacity of 2,5 million tons of
cement per year, it has now been extended
by LOESCHE technology.
LOESCHE’s order was for two LM 60.4
vertical roller mills (VRMs) for grinding
cement rawmaterial and an LM 70.4+4 CS,
the biggest LOESCHE VRM, for grinding
cement clinker.
This mill is designed for a capacity of
more than 370 t/h and has required a new
drive systemoffering an operational power
up to 8 800 kW to be developed. This was
undertaken by LOESCHE in close coopera-
tion with RENK AG Augsburg with input
from the end-user, LafargeHolcim, as well
as from a renowned technical university in
Germany, being taken into consideration.
The innovative result is the COPE
(Compact Planetary Electrical) drive. It is
designed for gearboxes from 4 000 kW
to 12 000 kW making a single and special
motor obsolete, as well as eliminating the
potential for failure in the fast running first
stage gear of conventional gearboxes.
The system has the same footprint
as a standard mill gearbox for VRMs and
also represents the first time use of eight
drive motors for a VRM gearbox. It is also
the first multiple drive in a VRM to operate
with or without VFD (Variable Frequency
Drive). It allows easy removal of individual
mill motor units to minimise down times
(approximately two hours) and has an
extremely compact design with motors
directly attached to the gearbox housing.
According to LOESCHE, the distinguish-
ing feature of this installation is that long
mill downtimes (of up to seven months)
as a result of repairs to conventional gear-
boxes are eliminated.
Implementing the COPE drive requires
a standard foundation. The replacement of
one of the eight small size motors is eas-
LOESCHE mills installed at cement plant
ily undertaken as they are readily available
and easy to install.
LOESCHE South Africa, tel (+27 11) 482-2933
The LM 70.4+4 CS mill in operation with the new
COPE drive at the cement plant in Mfamosing.