ABB was recently contracted to supply gearless mill drive (GMD) systems for two 38 foot semiautogenous grinding (SAG) mills at the Serra Azul iron ore mine in Brazil. The Serra Azul mine unit, owned by MMX Mineração e …

The current paper looks at evaluating the merits of large geared mills versus gearless driven mills by evaluating the following factors: The capability of currently available systems in terms of power and mill diameter Efficiency in terms of overall electrical power consumed vs mechanical output power Capital cost Running costs Cooling requirements in terms of air versus water cooling ...

In [1], Svalbonas reviews the states-of-the-art in the design of grinding mills and ring-motors (for gearless drives). He concludes that failures in ring motors occurred because the structural design of these motors had not been validated through measurement. Svalbonas expresses his hope that gearless drive manufacturers will follow the example ...

Gearless mill drive (GMD) technology has further expanded the use of large SAG milling allowing Outotec to produce the world's largest SAG mill of 42' in diameter drawing power at 28 MW. Today, Outotec is the world leading supplier of gearless SAG mills operating globally.

With this cement installation, it is possible to find the optimum production by changing the following: a) Mill speed from 13.0 rpm to 14.5 rpm (68.4% to 76.31% of critical speed). b) Diaphragm opening (in division head from open to closed position). c) Auxiliary fan blade speed from 50 to 150 rpm. d) Feed of clinker, gypsum and gypsum tailings.

Gearless Motor Drives for Grinding Mills . Fig. 1, General scheme of a Gearless Mill Motor drive [24]. of the airgap is in the range of 15-17 mm. A tolerance of

Outotec Premier™ horizontal grinding mills are customized and optimized grinding solutions built on advanced simulation tools and unmatched expertise. A Outotec Premier™ horizontal grinding mill is able to meet any projects needs, even if it means creating something novel and unseen before. Learn more about the Premier ...

A cycloconverter-fed gearless mill drive is a drive system that has hardware and software protection functions to protect the equipment in case of abnormal operating conditions, malfunctions or ...

general, the bigger the mill diameter, the lower are the mill operating and critical speeds. Thus, for larger mills the number of poles will increase. As a result, the number of poles can vary from 48 to 72 poles (Fig. 3.) with typical mill speed requirements of about 10 rpm for larger SAG mills and about 15 rpm for smaller ball mills. Figure 3.

A grinding mill liner has a plurality of liner elements with respective bolt passages that are placed such that the passages, when the liner is installed into a mill shell, are placed outside a footprint of a peripheral device on the mill shell. ... Most typically, the peripheral device is a gearless motor drive that is operationally coupled to ...

The availability and reliability of large grinding mills and their Gearless Mill Drives (GMDs) are of paramount importance for the grinding process. Although GMDs have been in service for decades, and are known for their operational efficiency (reliability and robustness with reduced operating cost per ton),

Grinding Mills; Gearless Mill Drives; System Analysis; Literature Reviews; Currently browsing category Grinding Mills Mill Castings – QC – Consultants. It is a terrible waste in terms of energy, cost, human effort, damage to the environment, etc., to scrap a mill casting. However sometimes, this is necessary and it does not take an expert ...

the mill, the mill itself becomes the rotor of the gearless motor. Building a track record ABB's experience in optimizing gearless solutions for grinding applications extends over 50 years, making it the market leader with the largest number of installed units worldwide. In 1969, ABB commissioned the first GMD for a ball mill at Ciments Lambert ...

Gearless mill drives are a well established solution for grinding applications in the minerals and mining industries. The paper describes the functionality and technical features of such drive systems as well as their advantages compared to other drive solutions. Due to the variable speed operation the grinding process can be optimized for ores with varying grinding properties.

SWEDISH-Swiss automation company ABB has revamped its ability predictive maintenance for grinding platform, which maintains, assesses and analyses gearless mill drive systems, with a cloud-based app allowing mine operators to check gearless mill drive performance from anywhere on their smartphones or tablets. Available for iOS and Android, …

Geared mills typically are power limited to approximately 9000 horsepower per pinion or 18,000 horsepower for a dual-pinion driven mill. Gearless mills, also called Ring Motor mills are employed when a mine operator desires a mill of greater than 18,000 horsepower, or in such cases, where the economics benefits justify the use of a Gearless ...

In the past the conventional method of driving large ball mills included some form of speed reducing gear between the higher speed driving motor and the lower speed ball mill. Process developments in the mining and cement industries have increasingly tended toward the use of ever larger ball mills for grinding their products. As the horsepower drive ratings required have …

The current paper looks at evaluating the merits of large geared mills versus gearless driven mills by evaluating the following factors: The capability of currently available systems in terms of power and mill diameter; Efficiency in terms of overall electrical power consumed vs mechanical output power; Capital cost; Running costs

Gearless motors up to 22 MW are in service in many of these ore processing plants. Gearless motor drives are also known as "ring motors" or "wrap around motors." The motor consists of a large number of magnets placed circumferentially on the shell of the grinding mill. This is similar to the rotor of a conventional motor.

A grinding mill liner has a plurality of liner elements with respective bolt passages that are placed such that the passages, ... Most typically, the peripheral device is a gearless motor drive that is operationally coupled to the mill shell in a position other than the end of the mill shell. Inventors: Kheifets, Alexander (Coquitlam, CA) ...

Looking at SAG mills for instance there are huge differences in CAPEX regarding their different drive systems. Especially in the the multi-MW class gearless drive systems seem to be a thing because of their advantages such as variable speed control and low maintenance requirements. How much of the total costs of a SAG mill relate to the drive ...

Several thousand grinding mills have been manufactured and have been in operation for the last century. The gearless drive came into the minerals industry in 1980 and as per their reference lists, Siemens have approximately 60 installations and ABB have approximately 85. The reasons why these gearless drives on mills came about in the late

Smarter processing for the future, in the area of SAG mill design involves accurate grinding test data, completing fi nal mill design in less than three months, and at a cost of less than US$80 000.

Gearless Drives for grinding mills. Among the most outstanding GMD's in operation are the ones for the Antapaccay mine. The SAG mill has an inner diameter (ID) of 40 feet, an effective grinding length (EGL) of 25 feet and …

Geared mills typically are power limited to approximately 9000 horsepower per pinion or 18,000 horsepower for a dual-pinion driven mill. Gearless mills, also called Ring Motor mills are employed when a mine operator desires a mill of greater than 18,000 horsepower, or in such cases, where the economics benefits justify the use of a Gearless ...

CONGA: THE WORLD'S FIRST 42 FOOT DIAMETER 28 MW GEARLESS SAG MILL T. Orser1, V. Svalbonas 2 and *M. Van de Vijfeijken 3 1Newmont Mining Corporation 10101 East Dry Creek Road Englewood, CO 80112, USA ... Semi-Autogenous Grinding (SAG) mill from and a 28 Mega-Watt (MW) Gearless Mill Drive (GMD) from ABB for the Conga Project …

A grinding mill liner has a plurality of liner elements with respective bolt passages that are placed such that the passages, when the liner is installed into a mill shell, are placed outside a footprint of a peripheral device on the mill shell. ... T. Orser, V. Svalbonas and M. Van de Vijfeijken, CONGA: The World's First 42 Foot Diameter 28 MW ...

demand for grinding mills beyond today's standards of 40ft is just part of the natural market development and will soon challenge the suppliers. Past experiences guided Siemens to establish a new culture in designing bigger and more powerful Gearless Mill Motors for the expected de-mand for 42ft and 44ft mills.

Go gearless to meet your business objetives by exceeding standard availability targets in your grinding operations. ABB's GMD is the most powerful mill drive system in the market to power semiautogenous (SAG), ball and autogenous (AG) mills, This 'workhorse' for grinding operations combines a robust, service-friendly and fit for purpose ...

Two 28 MW gearless mill drive systems (GMDS) are operating in the mine's 12-metre SAG mills and four 16.5 MW GMDS are employed in 26 ball mills along with associated control systems. "Gearless mill drives are the 'workhorses' for grinding operations which are at the heart of any mine. The six ABB GMDs at the world class Cobre Panama project are ...

With this cement installation, it is possible to find the optimum production by changing the following: a) Mill speed from 13.0 rpm to 14.5 rpm (68.4% to 76.31% of critical speed). b) Diaphragm opening (in division head …

The SAG mill was fitted with a gearless drive with a power rating of 24 MW and the ball mills were also fitted with gearless drive systems, each providing 16.4 MW.

That is why the gearless drive of a grinding mill is one of the most crucial pieces of equipment in the concentrator and why it is subject to particularly high demands. Siemens has provided about 80 SIMINE Gearless mill drives …

The size reduction, crushing and grinding, is one of the main stages in mineral processing, because of energy, material and maintenance costs. Looking at economy of scale, new projects consider the use of big mill grinding circuits, where larger power gearless motor drives with cycloconverters in the range around 20 MW are being applied for ...