SAG and AG Mills operate by lifting ore/grinding media and dropping it on the operating bed of the mill charge. High impacts from lifting ore and media promote impact breakage which is the primary mechanism for size reduction in the mill.
Utah, SAG mill and a 11,200 kW gearless drive for the El Teniente, Chile, SAG mill. In a continued call for larger, even more powerful drives, Siemens kept pace. In 1996, Freeport ordered the first gearless drive for a 38-foot SAG mill located at the company's Grasberg plant in Indonesia. This gearless drive …
The Gearless Mill Drive system consists of the ring motor with its feeding cycloconverter, pre-installed in an E-house. It also includes the excitation rectifier, the automation sys-tem (for mill and motor) including HMI, monitoring and diagnostic system, MCC's (for mill and drive auxiliaries),
The company selected ABB's 26 MW gearless mill drive system (GMD) for the mine's 40 ft SAG mill, as well as other drives, electrical infrastructure equipment and a long-term service agreement (LTSA). This is expected to reduce operating costs, improve process throughput and reliability while saving energy and keep equipment in top form.
Gearless Mill Drive Sales Rev Up to Meet Demand By Russell A. Carter, Managing Editor. Gearless mill drives are becoming the drive system of choice on large AG, SAG and ball mill installations for new projects and existing mill expansions. At least 31 GMDs have been ordered from Siemens and ABB, for …
II. BACKGROUND: SEMIAUTOGENOUS GRINDING (SAG) MILL WITH A GEARLESS DRIVE Fig. 1 shows the general scheme of a mill with gearless motor drive. The rotor poles of the synchronous machine are bolted to the mill. There is no gear, because the elec-tromagnetic torque is generated directly to the mill. The sta-
• 28 MW GMD for a 40' SAG mill • 28 MW GMD for 42' SAG mill Whether it is size or an installation at the highest altitude (4600 m.a.s.l.), ABB's GMDs are well positioned to contribute to the building of larger and ever more powerful mills. — Leading the gearless mill drive evolution The ABB gearless mill drive (GMD) is the most powerful ...
Gearless AG/SAG mills. With the proven use of gearless drive technology, the limitation of AG/SAG mill size due to gearing constraints has been eliminated. is the world's leading supplier of gearless AG/SAG mills.
E&MJ reported in October 2010 (See "SAG Mill Gearless Drives Go to South American Projects,"p. 102) ABB Group's Minerals Division had won an order from Newmont Mining Corp. to engineer three gearless mill drive (GMD) systems to be installed at its Yanacocha Minas …
Jan 19, 2016· The mills at Sentinel in Zambia are amongst the world's biggest, with 2 off 40 ft SAG mills complete with 28 MW drives, and 2 off 28 foot-ball mills with 22 MW drives. For mines of this size ...
Gearless Warp Around SAG Mill View Larger Image For almost a decade now, very good operating experiences have been gained with a total of 28 gearless ring motor drives in the cement industry, driving tube mills with diameters of 2.5 to 4 meters with drive powers ranging from …
reliable drive system for SAG mills. Early SAG mills had a diameter of about 32', later increasing to 34, 36, 38 and 40'. At the same time the mill volume also increased. Typically a SAG mill has a much larger diameter compared to its length. Yet the SAG mill of Newmont's Yanacocha mine in Peru is a single
The first Gearless Drive has been operating successfully with this control for more than 30 years. A phase of con-tinuous improvement and further development followed ... Whether you're talking about SAG or ball mill, space is a sensitive subject, especially in the concentrator.
Siemens is now able to provide to mining companies a gearless drive system for SAG mills with a tube diameter of 42 feet. This enables throughput to be almost doubled in comparison with the 38-foot mills commonly used today. With this innovation, Siemens is responding to the rising demand for larger and more powerful drives in mining.
Siemens' gearless drive technology of 99.46 to 99.71% - as confirmed by real operational data from the Antapaccay mine in Peru. It was the first plant worldwide to use gearless drives for both applications. KEYWORDS Gearless Mill Drives, Gearless Conveyor Drives, Availability, SAG Mill, Ball Mill, Overland Conveyor, Antapaccay 15
With the proven use of gearless drive technology, the limitation of AG/SAG mill size due to gearing constraints has been eliminated. is the world's leading supplier of gearless AG/SAG mills. Features The experience gained from installation and operation of these mills enables us to offer mills of up to 35,000 installed horsepower or more.
SAG is an acronym for Semi-Autogenous Grinding. SAG mills are autogenous mills but use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor.
gearless drive mills and crushers and mw . sag mill gearless drive The direct approach The gearless design for drive systems first used in a mill in 1969 and then a belt To my knowledge there are no geared drives powering a Read more.
The Siemens 42-ft Gearless Mill Drive, still an evolutionary design approach? (SAG Conf. 2015) Optimization of the drive system for a cyclone feed pump (SME 2015) Increasing availability through advanced Gearless Drive Technology (CMP 2014) Design and dynamic behavior of large ring motors for grinding mills (SMMH 2012)
Gearless Mill Drive Protection Improvements and Its Behaviour at …. Laguna Seca concentrator uses a SAG mill and three ball mills, all driven by gearless mill drive (GMD) systems.Table 1 gives … the GMD will work fine. »More detailed
SAG Mill Gearless Drives Go to South American Projects. October 2010 | Suppliers Report. In early September, ABB Group's Minerals Division announced it had won an order from Newmont Mining Corp. to engineer three gearless mill drive (GMD) systems to be installed at the Yanacocha Minas Conga oxide copper-gold project in Peru.
Gearless mill drive (GMD) technology has further expanded the use of large AG/SAG milling allowing to produce the world's largest SAG mill of 42' in diameter drawing power at 28 MW. Today, is the world leading supplier of gearless AG/SAG mills operating globally.
advantageous features which were previously exclusively available on gearless mill drives. GRINDING CIRCUIT The grinding circuit for the Copper Mountain project consists of one FL SAG mill and two FL ball mills. Figure 1 - Overview grinding circuit The Copper Mountain SAG mill is 10363 mm [34 feet] in diameter and 6096 mm [20 feet ...
Siemens, the company that introduced Gearless Mill Drives (GMD) to mining industry started up its first GMD on a ball mill in Norway in 1980. The mill and its drive system are still in service. Today, GMDs are mainly used for SAG mills between 36 and 40 feet (10.7 to …
Presently the gearless drive is more costly than the complete mechanical portion (mill rotating element and accessories supplied by the mill manufacturers) and hence the customer/consultant needs to have two parties to deal with from the start of any project. There is an interface between the mill vendor and the gearless motor supplier.
Marsh 1 WHY shift to the gearless drives in mineral processing ??? Mill size – grinding economies of scale Relative lifecycle cost Lower power consumption Robust design Avoiding critical open gear power trains Variable speed Compatibility with processing plants Engineering design efficiencies Availability Minimal downtime
Siemens has modernised a gearless grinding mill drive at Newcrest's Cadia Valley Operations, near Orange in New South Wales, Australia. This is the first time that a gearless grinding mill had been equipped with a Sinamics SL150 cycloconverter control.