Engineering and Project Management History
32' x 14' SAG Mill Engineering Support ... Pad bearing inspection report for SAG mills Trunnion bearing advice and support Discussion paper GMD vs Geared Drives in 17-18MW range QA/QC for installation of girth gear Telfer Gold Mine, WA Critical spares review Telfer Gold Project, WA
Gearless mill drives - ABB
power ratings relative to the mill diameter, offer higher efficiency and throughput, round-the-clock reliability and the opportunity to mine in remote areas. This makes low ore grades economical to grind. ABB has delivered some of the world's largest GMDs: • 22 MW GMD for 28' ball mill • 28 MW GMD for a 40' SAG mill
INNOVATION NEWS Mills and GMDs - library.e.abb.com
GMD for the world's first 42' SAG mill for the Minas Conga oxide gold copper project in Peru. There are numerous GMD projects for 40' SAG mills in the pipeline for the near future, as well as some other 42' SAG mill projects. Furthermore, ABB has GMD designs ready for 44' diameter SAG mills with a rated power of up to 35 MW.
SAG Mill | Autogenous and Semi-Autogenous Mills | FL
Single stage SAG Mills are very beneficial in reducing CAPEX for plants with a staged throughput approach. When future tonnage is to be increased, the SAG Mill can feed downstream ball milling to boost capacity. Fuller-Traylor SAG/AG …
Ball Mill - an overview | ScienceDirect Topics
3.5.2.2 Ball Mills. The ball mill accepts the SAG or AG mill product. Ball mills give a controlled final grind and produce flotation feed of a uniform size. Ball mills tumble iron or steel balls with the ore. The balls are initially 5–10 cm diameter but gradually wear away as …
ABB gearless mill drive system to power SAG mill
It is situated near the Newmont Yanacocha gold mine, where an ABB GMD has been operating successfully since early 2008.The contract includes the engineering for a 28 megawatt GMD system for a 42 feet SAG (semiautogenous) mill, the world s …
TECHNICAL AND COMMERCIAL BENEFITS OF GEARLESS MILL …
SAG mills have a power higher than 10 MW. Even ball mills have a power larger than 10 MW. For this reason, they have an important impact in energy consumption and in the operation of the power distribution system. Figure 1. Picture of a typical GMD system for a SAG mill Figure 2 presents the power circuit of a cycloconverter fed synchronous motor.
Mill Pinion Failure Modes
Gearless mill drives - ABB • 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. Keep Reading
mill shaft power of gmd sag mill - coopspizza.fr
SAG mills . Gearless mill drive (GMD) technology has further expanded the use of large 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 SAG mills operating globally.ball mill drives maldivedelsudsalento.
advantages of gearless drives on ball mills
The gearless design for drive systems – first used in a mill in 1969 and then a belt conveyor ... Gearless drives also offer an energy-efficiency advantage. ... a 29 MW drive for the 40-foot SAG mill and two 22 MW drives for the 28-foot ball mills. Get Price.
SAGMILLING.COM .:. Articles
An updated data set for sag mill power model calibration This paper expands the SAG mill survey database published by the Author at Procemin 2013. The new database includes 49 published SAG/AG mill surveys and includes mills from all over the world.
Mill (grinding) - Wikipedia
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 ...
Gearless mill drives - Grinding | ABB
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 design to provide highest throughput, reliability and availability for your processing plant.
Gearless Ball Mill India
gearless ball mill india gearless ball mill india ABB's GMD is the most powerful mill drive system in the market to power semiautogenous SAG ball and autogenous AG mills This 'wo Get price gearless ball mill 24x36
Grinding Mill For Tar Oil Malaysia
Gmd System For Toromocho Mine. As a result abb developed three of the largest diameter and most powerful drive systems for a sag and two ball mills installed at the highest altitude to date the fully integrated and optimized solution for the grinding circuit consists of 1 x 28 mw gmd to power the 40 ft sag mill 2 x 22 mw gmds to power two 28 ft ...
A mill power equation for SAG mills | SpringerLink
where m p is in kW; D is internal mill diameter (meters), L is internal mill length (meters); J is total fractional charge loading of the mill; J B is the fractional mill filling by balls; ε B is the effective porosity of the charge, taken as 0.3; ρ s and ρ b are true densities of rock and balls (tons per cubic meter), respectively; w c is the weight fraction of rock in water and rock in ...
ABB Library - Gearless Mill Drives
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 ...
SAG Mill Grinding Circuit Design - 911metallurgist.com
This refers to high-aspect AG/SAG mills. Ball Charge Motion inside a SAG Mill. With a higher density mill charge. SAG mills have a higher installed power density for a given plant footprint relative to AC mills. With the combination of finer grind and a lower installed power density (based on the lower density of the mill charge), a typical AG ...
What's the Difference Between SAG Mill and Ball Mill ...
The biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1 mm. The calculation shows that the crushing ratio can reach 3000 ~ 4000, while the ball mill's ...
The engineering and process effects of choosing a motor ...
The SAG mill power draw model of Austin (using the cali-bration by Doll, 2013) is used to predict the process power draw at the mill shell, Pshell, and the efficiency losses for the drive's mechanical components based on Doll (2012) are used to determine the motor output power, P. The effect of varying the mill speed as a fraction of the critical
ball mills motor
• 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 GMDs are well positioned to contribute to the building of larger and ever more …
How digitalized gearless drive technology results in ...
When used to power semi-autogenous (SAG), ball and autogenous (AG) mills, GMDs provide improved throughput, reliability and availability at processing plants Traditional ring-geared mill drives have a ring-shaped gear that encircles the mill and drives it through one or two pinions followed by conventional motors.
What's the Difference Between Ball Mill, Rod Mill and SAG ...
Ball mill： Ball mills are the most widely used one. Rod mill： The rod mill has the highest efficiency when the feed size is <30mm and the discharge size is about 3mm with uniform particle size and light overcrushing phenomenon. SAG mill: When the weight of the SAG mill is more than 75%, the output is high and the energy consumption is low ...
SAG Mill Process Control - Grinding & Classification ...
If the SAG mill is not intended to be the rate-limiting step in a process plant, then it is best to adjust the SAG load (and power) to hold a constant tonnage to satisfy another constraint elsewhere. Underground mines are an example: the hoisting capacity of the mine shaft is the rate-limiting step in the process, and the SAG mill must adapt to ...
THE ENGINEERING AND PROCESS EFFECTS OF CHOOSING …
Gearless Mill Drive (GMD) or a conventional gear drive. T = P × (2π × ω)−1 ( 1 ) where, T is motor output torque measured at the output shaft (pinion) or mill shell (GMD), N·m; P is motor output power measured at the output shaft (pinion) or mill shell (GMD), W; ω is the motor speed, revolutions per second or Hz.
GROSS POWER CALCULATOR - SMC Testing
A reasonable working estimate to use in the case of gear-and-pinion drives would be 6-7%, ie the estimated power at pinion would be about 6-7% lower than the gross power draw. Gearless drives (also known as wrap-around motors) are quite different to gear-and-pinion drives.
VFD dimensioning: High altitude - Drive Services
Medium voltage VFDs operate there successfully driving large SAG and ball mills, pumps, conveyors or fans. Figure 4: Gearless Mill Drive (GMD), courtesy of ABB Figure 4 shows a typical gearless mill drive (GMD) featuring so called ring motor (introduced in 1969 by ABB): the rotor poles are fixed directly to the mill shell and the stator is ...
Gearless Drives for Ore Conveying and Grinding - Cmms ...
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). The current size and power limits for GMD's are 42 feet and up to 35,000 kW. Among the most outstanding GMD's in operation are the ones for the Antapaccay mine.
Increasing availability through advanced Gearless Drive ...
Mill speed can be adapted to upstream and downstream processes – avoids overgrinding, and optimizes load distribution between SAG and ball mill (Mular, Halbe & Barratt, 2002). Power consumption is influenced by load respectively torque and mill speed. This means that further energy can be saved if a mill speed below the rate speed is re-
Mining and mineral processing industries
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.