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Ring-geared mill drives - Grinding | ABB

Mill load sharing – Maintains equal torques on dual pinion mills throughout the whole speed range. Controlled rollback – Prevents backlash and reduces downtime. Mill power ride through – Keeps the mill operating even under voltage dips. Over-duty cycle – Avoids unexpected downtime if the mill gets overloaded.

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Large Sag And Ball Mill Drive Systems

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.

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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 ...

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the pieces of sag mill in lumwana mine

German Technology Large Capacity Mine Mill MC World. SAG mills (semiautogenous grinding 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 ...

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Ball Mill For Mining - beckers-muehle.de

Gearless Mill Drives Grinding ABB. ABBs GMD is the most powerful mill drive system in the market to power semiautogenous SAG ball and autogenous AG mills This workhorsefor grinding operations bines a robust servicefriendly and fit for purpose design to provide highest throughput reliability . Gold Ore Impact Flail Processing Rock Quartz Crush Mill

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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-

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Paper # 25 - Copper Mountain Overview on the Grinding ...

The Copper Mountain SAG mill is 10363 mm [34 feet] in diameter and 6096 mm [20 feet] long. It is a grate discharge mill with an inside diameter of 10363 mm [34 feet] and a grinding length of 5334 mm [17.5 feet]. The mill is driven by two 8,500 horsepower ABB motors. Figure 2 - …

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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.

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FACTS brings power stability to mining equipment | ABB

GMDs are high-efficiency, variable-speed motors with powers up to 30 MW and are considered the most effective solution for high-power mills, especially when the total cost of ownership is considered. The GMD's synchronous motor is fed by a cycloconverter, which is a device that converts AC to a lower frequency AC with no intermediate DC link [1].

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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.

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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 …

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EFFECTS OF GRINDING MEDIA SHAPES ON BALL MILL …

Figure 5.11 Power variation with mill speed for different media shapes (J=15%).86 Figure 5.12 Power variation with mill speed for different media shapes (J=20%).87 Figure 5.13 Power variation with mill speed for different media shapes (J=25%).87 Figure 5.14 Variation of mill power draw with mill filling, J (cylpebs media)…..88

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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.

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Ball Mills - Mineral Processing & Metallurgy

In general, therefore, the required mill power is calculated using the following equation. where n is the number of efficiency factors, EFi, used and fo is the feed rate of new ore to the mill. The power calculated from equation 2 can be looked up in published tables (Rowland and Kjos, 1978) and the correct mill size and type can be selected.

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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

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Grinding Circuit - an overview | ScienceDirect Topics

The crushed pebbles fall directly onto the SAG mill feed belt and return to the SAG mill. SAG mill product feeds two parallel ball mills of 6.6 m×11.1 m (internal diameter×length), each with a 9.7 MW twin pinion drive. The ball mills are operated at a ball charge volume of 30–32% and 78.5% critical speed.

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how does the sag mill works

High Gradient Magnetic Separator. how does the sag mill works T00:01:34+00:00 PAI SAG Mill Training YouTube. Jan 08, 2016 In this training module, we'll cover the workings of a semiautogenous grinding mill, or SAG mill, that's designed to be the first stage of a grinding circuit Ore that's crushed in a primary Oct 12, 2017 SAG mill make use of steel balls included …

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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.

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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

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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 ...

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abb ball mill operation - vaikuendokrinologija.lt

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) m

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THE ENGINEERING AND PROCESS EFFECTS OF CHOOSING A …

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.

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Benefits of continuous data acquisition from critical ...

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 power ratings up to 28 ...

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SAG Mill Grinding Circuit Design - 911metallurgist

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 ...

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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.

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sizes of sag mills - cigar2019.nl

calcul d usure blindage sag mill; sag mill machine; mill shaft power of gmd sag mill; average temperatures for a sag mill; spesifikasi sag mill; sag mill shell bolt of 79; vibrating screen sizes; c est quoi sag mill; 18 x 9 sag mill; the maximum reduction ratio of sag mill; sag mill shell; outlet size of a sag mill; rod mill sizes in gold plant ...

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Mining Mills Mining Used For Sale

Used Sag-mills For Sale - Used Mining Processing Equipment. UNUSED FL 36' x 24' Dual Pinion SAG Mill with 2 ABB 9,000 kW (12,069 HP) Motors for Total Power of 18,000 kW (24,138 HP) Manufacturer: FL Inventory ID: 6C-HM03

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SAG Mill | Autogenous and Semi-Autogenous Mills | …

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 Mills range in size from 4.3m through 12.2m in diameter with powers as high as 28,000 kW.

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sag mill dual pinion geared drive | Prominer (Shanghai ...

Sag Mill Drives: Girth Gears At 18,000 Hp. The single helical SAG mill girth gear, which is cast in four pieces, has 362 teeth, 0.75 DP, 863.6 mm face width, 12.4 m outside diameter and a 10.5 m diameter bore."The SAG mill is 34 ft. in diameter, dual pinion with 12,000 hp," says Neal Biege Sr., head of global marketing for FL . Get Price

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INNOVATION NEWS Mills and GMDs - library.e.abb

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.

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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.

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worlds largest sag mill - atmosfera-lubawa.pl

ft x ft vecor sag mill. Semiautogenous grinding (SAG) mill liner design and development D. Royston towards largersized SAG mills with diameters of 10.4 m (34 ft) and above, with the largest being 12.2 m (40 ft) in proportion of SAG mill power and this proportion falls as the liners wear (and lifting capacity falls) even when mill .

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GMDs: the driving force behind sustainable mill operations ...

By eliminating components that limit torque transfer and achievable power, GMDs are now the preferred solution for large mills. ABB GMDs provide the power behind many of these mills and the global technology leader has even designed, manufactured and delivered the world's largest mill comprised of a 28MW, 42ft SAG.

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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 …

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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 ...

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Autogenous and Semi-Autogenous Mills - ScienceDirect

The SAG mill had a 6–8% ball charge and the power consumption was 8 kWh/t, which agreed well with the expected value. 9.6. Problems. 9.1. In an SAG mill the dimensions of the mill were 9.75 m × 3.5 m and the specific gravities of the mineral and that of the balls charged were 4.1 and 7.9, respectively.

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selection criteria for sag mill drive system

selection criteria for sag mill drive system. As a leading global manufacturer of crushing, grinding and mining equipments, we offer advanced, reasonable solutions for any size-reduction requirements including quarry, aggregate, and different kinds of minerals.

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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 ...