Gearless mill drives Gearless mill drives (GMD) for semiautogenous (SAG), ball and autogenous (AG) mills eliminate the typical mechanical components of the drive train (shaft, gearbox, pinion and ring gear). In 1969, ABB delivered the first GMD ever, which is still in operation today. The upper limit of the power range today is about 35 MW.

sag mill gmd how does it work BINQ Mining. Nov 07 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 systemsTable 1 …

• 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 Mill Grinding Circuit Design - 911metallurgist. SAG Mill Design and Specification . The Kidston plant was designed to process 7500 tpd fresh ore of average hardness; but to optimise profit during the first two years of operation when softer oxide ore will be treated, the process equipment was sized to handle a throughput of up to 14 000 ...

how does the sag mill works_Mill (grinding) - WikipediaA SAG mill with a 4439; (13.4m) diameter and a power of 35 MW (47,000 HP) has been designed. Attrition between grinding balls and ore particles causes grinding of fin

Ri Sag Mills For Iron Ore Grinding Abb To Supply Mill Drives For Iron Ore Processing In Brazil. December 8, 2011 abb will supply gearless mill drive gmd systems for two 38foot semiautogenous grinding sag mills at the serra azul iron ore mine in brazil. the serra azul mine unit, owned by mmx mineragco e metalicos, an ebx group company, is located in the iron …

The SAG mill pinion energy W SDT (kWh/t) and SAG discharge Bond ball mill work index S d-BWI (kWh/t) are then used to calculate the total energy to grind the ore from 80 passing 152 mm to 80 passing the client specified final product size P 80.This information along with the ore specific gravity is used to calculate necessary mill sizes and ...

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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 ...

- Energy savings typically up to 750,000 USD per annum for a 20MW SAG Mill considering a power supply price of 11 US Cents per kWh - Erection and commissioning works on site are reduced by using a completely installed, wired and pre-commissioned E-house. Details of the installed components are listed below in the next paragraph.

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 12.2 m) and ball mills from 24 to 28 feet (7.3 to 8.5 m).

Gearless mill drive system (GMD) 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 ...

sag mill gmd how does it workBINQ Mining. CONGA THE WORLD S FIRST 42 FOOT DIAMETER 28 MW GEARLESS SAG MILL. The test and study work showed that a single line 42 ft SAG mill circuit gave the most The 42 ft diameter Conga SAG mill GMD power density value of 0.67 is not an »More detailed

SAG mills grinding media includes some large and hard rocks, filled rate of 9% – 20%. SAG mill grind ores through impact, attrition, abrasion forces. In practice, for a given ore and equal processing conditions, the AG milling has a finer grind than SAG mills. How does a sag mill work?

sag mill gmd how does it work - binq mining. mill (grinding) wikipedia, the free encyclopedia. wi is the work index measured in a laboratory ball mill . Get Price> Application Of Operating Work Indices In Autogenous

SAG mill conference, provided details of the then largest gear drive in operation on a SAG mill (34ft x 18ft) at Escondida 13.4MW, which ... FEA & basic design work which takes a further 6/8 weeks. This is not ... Mill. In this case the GMD requires slightly less space but it does require more concrete. Refer to Figures 11 through 14 below.

By combining with SAG discharge and screening on the SAG discharge screens, top size control to the ball-mill circuit feed is maintained while still unloading the SAG circuit (Mosher et al, 2006). A variant of this method is to direct pebble-crushing circuit product to the ball-mill sump for secondary milling: while convenient, this has the ...

ABB has been awarded the delivery of a 23MW SAG Mill GMD system. Currently under commissioning phase and expected to reach the nominal production by beginning of 2020, this system is the first one to be in operation serving the spanish mining industry.

Gearless Mill Drive (GMD) systems are characterized by having the motor wrapped around the mill like a ring. For this reason, they are often referred to as ring motors. The rotor poles are attached directly to the mill (head) flange, and hence the rotor becomes an integral part of the mill, as shown in figure 4.

The 28 MW GMD for the 40 ft SAG mill of the Toromocho Project has been delivered and will be installed at an even higher altitude of 4,600 masl (over 15,000 ft) … »More detailed. outokumpu ball mill power ratings; sag mill gmd how does it work; hardinge ball mill liner 11ft length 8 ft diameter; how brake operated in auxiliary drive of ball ...

By combining with SAG discharge and screening on the SAG discharge screens, top size control to the ball-mill circuit feed is maintained while still unloading the SAG circuit (Mosher et al, 2006). A variant of this method is …

In conventional mills the diameter of the mill is smaller than its length. In autogenous mills the diameter is greater than the length. They can be as much as 40+ feet in diameter. Patented in 1959, AG Mills are not so popular any more. This large diameter of mill is required to achieve the impact necessary to grind the ore.

how does a sag mill work - Crusher Machine. how does a sag mill work . Mill (grinding) - Wikipedia, the free encyclopedia To calculate the needed grinding work against the grain size changing three .

Ball Mill SAG Mill Figure 2 Core pressing system with spring plate/washer and re-tightening statistics in a typical installation Access to the inside of the motor and the cooling system The easier the access to the inside of the motor is, the more convenient and efficient is …

SAG mills are autogenous mills that also 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. A SAG mill with a 44' (13.4m) diameter and a power of 35 MW (47,000 HP) has been ...

SAG mill design, GMD design and the associated component manufacturing. This paper also addresses, where applicable, the potential reliability differences between the initially proposed 40 ft SAG mill and the finally accepted 42 ft SAG mill. KEYWORDS SAG mill, 40 ft, 42 ft, gearless mill drive, GMD, SAG manufacture, reliability THE PROJECT

Rod Mills How Do They Work Rod mills are very similar to ball mills except they use long rods for grinding media The rods grind the ore by tumbling within the the mill similar to the grinding balls in a ball mill To prevent the conditions leading to rod charge tangling the length to diameter ratio is maintained at 14 to 16 Rod mills accept feed up to...

Figure 4: Two SAG Mills 24MW each and Two Ball Mills 16.4 MW each with Gearless Mill Drives For larger applications the well-proven Gearless Mill Drive (GMD) technology has shown to be very effective since its introduction in mining in 1980; currently in operation for horizontal mills up to 40 feet (~12.2m) diameter with

The test and study work showed that a single line 42 ft SAG mill circuit gave the most favorable project economics in comparison to an equivalently powered single line 40 ft SAG mill circuit. This paper does not address the process design or the project economics, but instead focuses on the key aspects of the SAG mill design, GMD design and the ...