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Acquisition enables ABB to further strengthen gearless mill drive system
Zurich, Switzerland, July 30, 2013 – ABB, the leading power and automation
technology group, announced today the acquisition of Alstom’s ring motor
business to enhance its gearless mill drive (GMD) system business. The parties
agreed not to disclose financial details of the transaction.
The business, based in Bilbao, Spain, has about 120 employees and will become
part of ABB’s Process Automation division.
Gearless mill drive systems are used in the mining industry for processing large
quantities of ore to extract metals such as copper, gold, platinum, iron and
The market for GMD systems is expected to grow due to rising demand for minerals
in emerging countries undergoing industrialization. Deeper mines with more
complex ore bodies and lower ore grades require the grinding of increased
amounts of material to yield the same volumes of metal. GMD systems are designed
to address the need for extremely high ore throughput, reliability and
availability of the grinding circuit.
“The acquisition will combine the leading ring motor product from Alstom with
ABB’s electrical offering for GMD systems, enabling ABB to enhance its position
as a strong vertically-integrated systems provider,” said Veli-Matti Reinikkala,
head of ABB’s Process Automation division. “The acquired expertise and market
strength will provide new opportunities for growth.”
The ring motor product and ABB’s current electrical offering for GMD systems can
only work in combination and are therefore fully complementary. The know-how,
experience and technology that this acquisition brings will enable ABB to
increase manufacturing capabilities and strengthen the ring motor business. In
the long term, end users will enjoy the benefits of ABB’s enhanced product
quality control and system performance.
The GMD eliminates all mechanical components of a conventional mill drive
system. By mounting the rotor poles directly onto the mill, the mill itself
becomes the rotor of the gearless motor. The gearless motor - also called wrap
-around motor or ring motor - is a very large synchronous machine which uses
power electronics and a magnetic field to control the speed of the motor
rotation. With no mechanical interaction between the stationary and rotating
parts, there is a significant reduction in the amount of energy used, fewer
parts and higher reliability. The motor power, so far, can go up to 28 megawatts
for such an application. An infographic of the ring motor and further visual
materials can be found
here (
Raw material from the crushing stage is typically fed to SAG (semi-autogenous),
AG (autogenous) and ball mills for further processing to break the rock into
smaller pieces. These mills are large rotating cylinders, from 10 to 15 meters
in diameter. They can grind hundreds of tons of ore per hour. For effective
grinding, these mills rotate at low speeds.
ABB ( is a leader in power and automation technologies that enable
utility and industry customers to improve their performance while lowering
environmental impact. The ABB Group of companies operates in around 100
countries and employs about 145,000 people.

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