Modern Mining February 2017

PRODUCT News

LOESCHE mills installed at cement plant

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-

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.

February 2017  MODERN MINING  43