variable speed sag mill
The SAG mill was installed with a fixed speed motor however the possibility to retrofit a variable speed drive with limited speed adjustment if it is found to be necessary was allowed
variable speed sag mill:The grinding circuit comprises one 8530 mm diameter x 3650 mm semiautogenous mill driven by a 3954 kW variable speed dc motor and one 5030 mm diameter x 8340 mm secondary ball mill driven by a 3730 kW synchronous motor
More Detailvariable speed sag mill:Each SAG primary mill BolidenAllis operates with two 5000 HP Ball Mills as secondary grinding stage The Electric Drive SIEMENS consists a 11000 HP synchronous motor of variable speed General Description of the Drive The SAG Mill Drive is mainly formed by a 11000 HP
More Detailvariable speed sag mill:Mill speed influences the power draw in two ways on the one hand mill power is the lineal product of the mill rotational speed and the torque applied so there is a lineal dependence on the other hand the centreof gravity of the charge is shifted withspeed creating a nonlineal dependence The
More Detailvariable speed sag mill:revealed a thermal limitation in the 3000hp LCI variable speed drive system at low mill speeds This event resulted in variable speed operation being suspended and the mill being operated at a fixed speed 76 of critical until a thorough analysis of the event could be completed DEVELOPMENT OF A SAG MILL CONTROLLER
More Detailvariable speed sag mill:Dec 19 2014 · Advantages of SER drives for SAG mills For large mills requiring variable speed the wound rotor motor and SER drive are economical for a total rating of approximately 2MW to 16MW Above 16MW the gearless drive cycloconverter is typically used because gearboxes and pinion gears reach their present limit in size
More Detailvariable speed sag mill:5 Low ball charge high speed SAG mill 4 ball charge 90 Nc A cross between AG and SAG for average competency abrasive ores Typically operated in RSA on Witwatersrand Gold Ore Driefontein Underground Kloof Jacobina 6 SAG mill with recycle crusher 8 – 15 ball charge Competent ores better suited to coarse grind sizes High aspect mills
More Detailvariable speed sag mill:ACS 1000 variable speed drive The replacement enabled AgnicoEagle to expand the milling facility increasing its output and to achieve the expected performance and stability View of the SAG mill 3360 kW at AgnicoEagle‘s LaRonde mine
More Detailvariable speed sag mill:Siemens also supplied the gearless drives for a 36ft SAG mill with a rated power of 15 MW and a 26ft ball mill with 155 MW of rated power recently installed at
More Detailvariable speed sag mill:One of three SAG mills with 975 m diameter and 2 x 4000 kW drive power These mills operate in conjunction with ball mills for iron ore grinding in Iran Ball mill for grinding lime stone for a flue gas desulphuri sation system in a Korean power station from limestone handling through to grinding
More Detailvariable speed sag mill:SAG and ball mills have grown in size and there are now many operational mills in the range of 28–40 feet in diameter with installed powers ranging between 8–20 MW The very high capacity of these mills and the common use of variable speed drives often result in operational problems
More Detailvariable speed sag mill:As a result the number of poles can vary from 48 to 72 poles Fig 3 with typical mill speed requirements of about 10 rpm for larger SAG mills and about 15 rpm for smaller ball mills The cycloconverter Fig 4 belongs to the group of line commutated static frequency converters free from circulating current
More Detailvariable speed sag mill:Variable needs require versatile grinding equipment Metso offers flexible autogenous AG mills semiautogenous SAG mills ball and pebble mills as well as stirred mills to fit your needs Wide offering Grinding mills spare and wear parts as well as maintenance and optimization services
More Detailvariable speed sag mill:Figure 1 Overview grinding circuit 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 175 feet The mill is driven by two 8500 horsepower ABB motors
More Detailvariable speed sag mill:Buy used Sagmills from AM King Industries We can help guide you to the best solution for your equipment needs EGL SAG Mill with 6300 HP 4750 kw Variable Speed Drive Manufacturer OUTOTEC Inventory ID 6CMI02 View Details BOLIDEN ALLIS CHALMERS 73m x 274m 24 x 9 SAG Mill with 3000 HP 2237 kW Motor Inventory ID 6C
More Detailvariable speed sag mill:Buy Unused Outotec 24 X 17 7325m X 52m Egl Sag Mill With 6300 Hp 4750 Kw Variable Speed Drive from AM King Industries Request a quote online today
More Detailvariable speed sag mill:OUR EXPERIENCE SAG Mill 52m 171 dia x 487m 16 Morgardshammar with 2000 kW Drive Powered by twin 1000 kW Toshiba 50 Hz wound rotor induction motors with speed reducers Mill can be repowered with 60 HZ motors
More Detailvariable speed sag mill:Mill rotational speed may be variable in which case increasing speed increases grinding capacity since this increases the rise and subsequent fall of ore and media – provided the mill is not run up to critical speed Mill speed variation has a large gain effect in terms of control and is important to compensate for variations in ore hardness
More Detailvariable speed sag mill:For SAG 2 Siemens supplies two 8 pole high speed induction motors to replace the existing slipring motors eliminating all brush or slipring related outages and maintenance activities The four identical variable speed drives VSD operating all four mill motors are Sinamics Perfect Harmony GH180 units
More Detailvariable speed sag mill:Feb 27 2008 · There are a number of reasons to select a variable speed drive for a SAG mill If you seek optimal performance over the life of lifters in the mill you need to modify mill speed as mill internal configuration wears Your objective should be 1 Optimize grinding performance mfgrs dont know best mill speed
More Detailvariable speed sag mill:Figure 1 Overview grinding circuit 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 175 feet The mill is driven by two 8500 horsepower ABB motors
More Detailvariable speed sag mill:mills SAG mills of over 40foot diameter have been constructed Like the ball mill the AGSAG mill will have a critical rotation speed above which grinding ceases Mill motor types There are three common motor types that drive the grinding mills described above – Gearless motors These variablespeed motors range up to 30 MW and have the highest system efficiency
More Detailvariable speed sag mill:Variable speed was required for the SAG mill Various options were considered to meet the specified speed range of 65 to 85 of mill critical speed and the final selection was the IES HyperSynchronous drive Slip Energy Recovery SER in conjunction with Wound Rotor Induction motors WRIM
More Detailvariable speed sag mill: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 SAGAG mill surveys and includes mills from all over the world
More Detailvariable speed sag mill:Sep 17 2013 · wound rotor motor is not the best option for SAG mills becuse the slip rings always are a problem even with liquid option is synchronuos motor in combination with variable frequency r if you already have the wound rotor motor the ERS operation is simple
More Detailvariable speed sag mill:The maintenance is reduced to a minimum Typically a 6 – 8 pole induction machine is used to turn the mill The motors are generally forced cooled this allows running the motor at very low speed approx 510 of nominal speed for service mode
More Detailvariable speed sag mill:The mill is driven by two GE horizontal synchronous variable speed motors one of which is depicted on the bottom right SAG mill feed is conveyed from the coarse ore stockpile The ore passes through a gyratory crusher where it is reduced to 8 inch diameter before being dumped on the pile
More Detailvariable speed sag mill:combination with variable densities and coarseorecompetencies the SAG mill feed rates vary significantly due to operating conditions and metallurgical parameters The original Phu Kham grinding circuit comprised of a SAG and a ball mill in SAB flowsheet arrangement each
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