### Mill (grinding) - Wikipedia

SAG mills are characterized by their large diameter and short length as compared to ball mills. The inside of the mill is lined with lifting plates to lift the material inside the mill, where it then falls off the plates onto the rest of the ore charge. SAG mills are primarily used at gold, copper and platinum mines with applications also in the lead, zinc, silver, alumina and nickel industries.

Get Price### SAG Mill - Mining engineering - Eng-Tips

01.06.2005· Anyway, SAG mills can be calculated as inefficient, except they do not require a large grinding load like ball and rod mills. Capital and operating costs have to be compared, system vs. system in order to assist with the selection. The feed suitability vis-a-vis the grind method is critical.

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Any failure to the gear system leads to the total system failure. Imagine driving a car with a broken gear in its gearbox. Knowing the various modes by which the gears tend to fail helps one to identify the problem at an initial stage and rectify the problem related to the gear. Now let us look into the various modes by which the gears fail: The various major areas by which the gears tend to ...

Get Price### A Method of C alculating Autogenous/ Semi-Autogenous ...

SAG mills mimic the same shortcoming. It follows that in order to obtain the speciﬁ c energy (SE) to achieve a certain transfer size, based on the 80 per cent passing value, an inefﬁ ciency factor must be applied to the SE of single stage ball mills, rod mills or AG/SAG mills when calculating power according to the Bond Third Theory method. Rod mill and AG/SAG mill products are similar and ...

Get Price### Ingeteam will supply VSD variable speed drive for .

The drive configuration for this project known as SBRS (Start Ball, Run SAG) meaning that the VSD is to soft- start with frozen charge detection the ball mill, run up to nominal speed, smoothly connect ball mill to the grid so that the ball mill is operating with fixed speed, then soft- start with frozen charge detection the SAG mill as well as operate the SAG mill with variable speed. Each ...

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The SAG mill is followed by two 20-ft diam., 7,500-hp gear-driven ball mills. Another type of drive, less commonly used, consists of a motor-driven speed reducer that is coupled to one of two ...

Get Price### Trunnion Bearing Assembly Ball Mill & Rod Mill

Metallurgical ContentBall Mill TRUNNION BEARINGSTrunnion BRONZE BUSHINGSTRUNNION BASE AND CAPBall Mill LUBRICANT JACKSBall Mill PINION SHAFT BEARINGS The first part of the mill that we will look at is the TRUNNION BEARING. This is a HYDROSTATIC BEARING which is a slow moving bearing that carries a heavy load. Usually it is constructed from Babbitt's metal. If you happen to .

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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 .

Get Price### Ring gear drives huge grinding mill | Machine .

The SAG mill is followed by two 20-ft diam., 7,500-hp gear-driven ball mills. Another type of drive, less commonly used, consists of a motor-driven speed reducer that is coupled to one of two ...

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has been selected to design and supply a 42ft x 25ft, (12.8m x 7.6m) 28MW gearless SAG mill, plus two 26ft x 42ft, (7.9m x 12.8m) 15.6MW ball mills and two VTM-1500-WB VERTIMILLS® for Newmont Mining's Yanacocha Conga copper-gold project in Peru. The 42ft diameter SAG mill is the world's largest and the first of its kind.

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Our largest mills has been delivered to SINO Site to date are Ø12.2m x 11m 28MW Gearless Drive AG Mills and Ø7.9m x 13.6m 2x8 MW Twin Pinion Drive Ball Mills. These mills are scheduled of start up on 2012. Our market share in China exceeds 80% with the largest mills supplied to date being a Ø7.9m x 13.6m 2x8.5MW Ball Mill and a Ø11m x 5.4m 2x8.5MW SAG Mill, being the largest in China ...

Get Price### SAG mill ball charge determination and its .

SAG mill ball charge determination and its influence on mill drive requirements Abstract: In semi-autogenous grinding (SAG), the grinding mill inventory, (i.e. volume of total charge, volume of ball charge, etc.) is important in determining the optimum operating condition for maximum production (tph), minimum specific energy (kwh/t) or lowest cost ($/t). A two-dimensional graphical method is ...

Get Price### SAG mills (semi-autogenous grinding mills) - .

SAG milling extends itself to many applications due to the range of mill sizes available. They can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill and some or all of the work done by a ball mill. SAG mills are also an optimum solution for wet grinding since crushing and screening in these ...

Get Price### SAG mills (semi-autogenous grinding mills) - .

SAG milling extends itself to many applications due to the range of mill sizes available. They can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill and some or all of the work done by a ball mill. SAG mills are also an optimum solution for wet grinding since crushing and screening in these ...

Get Price### How Ball Mills Work (Engineering and Mining) - .

20.06.2019· Learn how a ball mill works, all of its main parts and some of its design features! This 3D animated video allows you to see all the internal parts of a ball...

Get Price### Grinding in Ball Mills: Modeling and Process Control

Keywords: Ball mills, grinding circuit, process control. I. Introduction Grinding in ball mills is an important technological process applied to reduce the size of particles which may have different nature and a wide diversity of physical, mechanical and chemical characteristics. Typical examples are the various ores, minerals, limestone, etc. The applications of ball mills are ubiquitous in ...

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Mill application features. Frozen charge protection – Detects frozen charge in the mill, minimizing equipment wear and liner replacements.; Coupling supervision – Detects if a failure or slippage occurs in the couplings and stops the system in case, preventing major damages.; Stand-still detection – Prevents the motors from re-starting if the mill is still rocking or moving after a stop ...

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has been selected to design and supply a 42ft x 25ft, (12.8m x 7.6m) 28MW gearless SAG mill, plus two 26ft x 42ft, (7.9m x 12.8m) 15.6MW ball mills and two VTM-1500-WB VERTIMILLS® for Newmont Mining's Yanacocha Conga copper-gold project in Peru. The 42ft diameter SAG mill is the world's largest and the first of its kind.

Get Price### Case Study - Grinding Mill Bearing Failure

The drive spindle has three (3) bearings: two (2) cylindrical roller bearings and one (1) ball bearing. The mill is being belt driven by a 100 hp, two-pole motor. The mill normally operates at 3,150 rpm. 1.Outboard Motor Bearing Legend 2.Inboard Motor Bearing 3.Inboard Mill Bearing* 4.Outboard Mill Bearing * Bearing that was failing. The mill rotor bearings, which are mounted in a steel ...

Get Price### TECHNICAL NOTES 8 GRINDING R. P. King

LG A mill power equation for SAG mills. Minerals and Metallurgical Processing. Feb 1990 pp57-62. Gross power No load power Net power drawn by the charge (8.13) The net power is calculated from Net power KD2.5L e! c./ Watts (8.14) In equation 8.14, D is the diameter inside the mill liners and Le is the effective length of the mill including the conical ends. ! c is the specific gravity of the ...

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