Orders for ABB gearless mill drives — giant motor and drive systems that enable mines to grind vast amounts of minerals and ore – are at record levels as the mining industry seeks to boost production to meet the global boom in demand.
ABB has won orders for some 18 gearless mill drives (GMDs) in the past 18 months alone as mining companies strive to meet the global surge in demand for raw materials by increasing production capacity and opening new mines. This represents a fourfold increase on ABB’s usual annual order intake.
ABB mill drives are a critical component in ore and mineral processing. They combine huge capacity and brute strength with energy-efficient operation and round-the-clock reliability. Compared to conventional geared drive systems, ABB GMDs offer better energy efficiency, superior reliability, increased process availability and longer lifespan.
GMDs are large cylindrical drums, as much as 40 feet (12 meters) in diameter, which grind mineral ore into smaller pieces for further processing. A typical 40-foot mill has a power rating of 21-26 megawatts (MW)*, a speed of 9 revolutions per minute and a grinding capacity of several thousand tons of ore per hour.
Energy consumed in grinding can be 50-70 percent of the total energy used to recover ore. Drives are an energy-efficient way to match mill speed to the needs of the grinding process. With no moving parts between the motor and the drum, a gearless mill is also extremely strong and can reliably process vast quantities of ore.
ABB delivered the world’s first GMD to a Lafarge cement mill in 1969 (it is still in operation to this day) and has broken the record for the world’s largest GMDs on several occasions over the past 40 years.