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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.
Some protection functions have tripped in the gearless mill drives operating at Minera Escondida and have been reviewed subsequently. This paper describes improvements in …
In 2010 Newmont made the decision to purchase a 42 foot (ft) Semi-Autogenous Grinding (SAG) mill from and a 28 Mega-Watt (MW) Gearless Mill Drive (GMD) from ABB …
method of driving SAG mills, Ball mills and other rotating elements. 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.
Fig. 1 depicts a gearless mil drive, where the mechanical power is transferred electromagnetically between the stator and poles of the rotor (Errath et al., 2003).Due to the mass flow, materials, and power involved in the process, SAG mills face the problem of high-energy impacts caused by steel balls cataracting against the shell of the mill, with …
Autogenous grinding is favored when the ore is quite competent and a fine grind is required. Semi-autogenous grinding is applied when fine crushing could cause severe problems or when ore is variable in hardness or competency. Figure 2 shows a typical conventional crushing-grinding circuit with three stages of crushing followed by …
A recent calculation on a 30′ diameter, 7000 Hp, semi-autogenous mill indicated that a flat end vs. conical end construction …
GMDs: 22 MW GMD for 28' ball mill 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 …
SAG mill drives (as GMDs) by some operators and principal motor designers/manufacturers until the reasons for known problems in design or manufacturing were better understood and resolved. Accordingly, the latest 40 ft dia. SAG mill is rated at 29 MW and 78% C.S., with a 42 ft dia. mill built but not yet operational. The more recent option
This work addresses some current issues involving design application of high-power drives employed in SAG grinding mills, highlighting industrial electronics aspects: complex …
As an example, early in 2006, Cia. Minera Doña Ines de Collahuasi had to make temporary repairs on the drive on the largest and newest of its three SAG mills at the Collahuasi copper mine in northern Chile, and then in …
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
Ringmotor of the Gearless Mill Drive (GMD) System. CYCLOCONVERTER Principle The Cycloconverter is a frequency changer which converts a poly-phase voltage with the frequency f1 into a single or poly-phase voltage with a different, lower frequency f2. On Gearless Mill Drives (GMD), the operational output frequency varies from 0.3 Hz up to …
Remedial design of the worldÕs largest SAG mill gearless drive. In: International Conference on SAG grinding, SAG2001, Vancouver, Canada, 2001. New performance enhancements technologies for the ...
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 stage mill (no ball mill after ...
• 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 ...
SAG mills use a combination of steel balls and rock particles as grinding media, while AG mills use only the ore itself. Both types of mills are used for grinding ore in mineral processing operations, but SAG mills are larger in size and can grind larger quantities of ore. AG mills, on the other hand, are smaller and are typically used for ...
The optimum operation was found after 3000 hours running. The capacity was some 10% over the guaranteed capacity. This large mill 17′ x 56′ is not less efficient than a smaller mill 10′ x 28′ used in comparative tests. Maintenance of "Gearless Drive" Mill. The lubrication system. This depended on gravity feed of oil to the bearing pads.
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 …
When mill diameter and mill power became again increased, only the Gearless Mill Drive (GMD) could be envisaged to cover this requirement above 10 MW. The GMD is by its nature a variable speed drive system. Process operators, once having the facility of adjustable speed, could not live anymore without it for SAG mills.
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 ... SAG mill, 40 ft, 42 ft, gearless mill drive, GMD, SAG manufacture, reliability THE PROJECT
(EGL) SAG mill driven by a 24,000 kW gearless drive. The SAG mill feeds two FL ball mills each 26 ft. in diameter × 40 ft. long (EGL), each driven by a 16,400 kW drive. The SAG mill is one of the largest volumetric capacity SAG mills in the world and represented the first 40 ft. SAG mill in Peru (Garcia & Villanueva, 2013 [1]).
SAGMILL NNDN RING 13uu PIN~ GEAR AIR CLUT SAGMILL I RINGMOTOR I I {I 1 1 Fig. 1 — Twin-pinion drive gear driven motor. Fig.2— Gearless mill with a ringmotor. of the grinding systems. NPCS were capital costs in Table 1 are based on variable speed ac drive complete determined on grinding systems that operations with three different produc- with …
Now I finished the calculation of flowsheet with pre-crushing, SAG mill and Ball mills. The result is follows: 1. Pre-crushing- three crusher MP-2500() for crushing from 300mm to 50mm. Two working and once in reserve. 2. Primary grinding- once SAG mill with size 42ft x 24ft, power motor 28MW. F80-50mm, p80- 2mm. 3.
Mill in Brazil and Lumwana having a 38ft, 18 MW SAG and one 26ft, 16 MW Ball Mill in Zambia, all three mills put in operation in 2008, as well as Los Bronces, Confluencia in Chile equipped with one 40ft SAG Mill of 22 MW and two 26ft Ball Mills of 16.4 MW commissioned in 2011. In the light of increasing interest in that technology various ...
Eleven 5MW gearless drives with synchronous motors running at low speeds (50-60rpm) drive three conveyors; two with four motors each and one with three. Two 20MW conveyors transport the ore from the open pit operation to the surface, overcoming an elevation change of around 1,300m, while the second conveyor feeds into a slightly smaller, 15MW ...
for a 20 MW SAG mill considering a power supply price of 11 US Cents per kWh. Erection and commissioning works on site are reduced ... 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- ...
The first Gearless Mill Drive (GMD) with a power of 6.5 MW was installed 1969 in a cement milling process in the cement plant Le Havre in France. In the first few years, the GMD was only used in the ... numerous GMDs for ball mills and SAG mills have been installed in the minerals industry. The main advantages are that the GMD is
Gearless drive for a SAG mill. Fig. 3 shows the comparison between a conventional pump drive and the gearless scheme using low-speed high-torque motor fed by a frequency converter. With a global efficiency of near 89% instead of 76%, the latter has an improvement in efficiency of about 13% because it has no gearbox losses.
Case studies: Aktogay and Bozshakol. ABB has partnered with Kaz Minerals to supply GMDs for the company's Aktogay and Bozshakol copper mines in Kazakhstan, both of which are expected to process 25 Mt/y of ore. ABB was awarded a multi-million contract to provide a 28 MW GMD for a 40 ft (12.2 m) SAG mill and two 22 MW drives for …