Variable Speed SAG Mills Motor Capability vs Mill Capability The specification of the prime mover of an autogenous semi autogenous mill involves an analysis of the likely operating conditions within the mill and the choice of a nominal operating speed For variable speed mills the operating range for mill speed has to be defined so that mill
Used Mining Equipment ColesMining com provide comprehensive used equipment solutions used SAG Mills used ball mills used rod mills used tower mills used Svedala used Allis Chalmers used Krupp Polysius used Mary used Dominion Engineering used used Hardinge used Denver used Allis Chalmers used Outotec used used Symonds used Fuller Traylor used Kemco Dorr
variable speed drive upgrade of the SAG mill lifter and grate design changes ball mill circuit grinding efficiency This paper summarises the chronology of
Advantages of SER drives for SAG mills Friday December 19 2014 I expect that this type of drive would be the most common large mill variable speed mill drive in the world s minerals processing industry for the range mentioned above for the last 15 years approximately
Thanks to ABB s ACS 1000 variable speed drive we are able to run the motor and the SAG mill at the required speed We no longer have to deal with plant shutdowns and are able to expand the milling facility increasing the output from originally 2 000 tpd to almost 8 000 tpd The ACS 1000 fully meets our expectations ACS 1000 key data
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
20191211 ensp 0183 enspTable of ContentsComminution Circuit DescriptionMill Availability and MaintenanceAdvantages and DisadvantagesVariable Speed SAG Mills Motor Capability vs Mill Capability The single line grinding circuit at Bond Gold s Colosseum mine consists of variable speed drive semiautogenous SAG milling and secondary grinding with a fixed speed ball mill
Low SAG Mill Critical Speed 7 replies Lower mill RPM lower throughput due to lower circulation rate at critical comminution zone near toe of charge where ore changes direction with maximum ore particle pressure and shear work are exerted Lower mill RPM lower charge lift shoulder height and therefore lower rock pressure at toe
2014101 ensp 0183 enspchallenges associated with the process design of single stage SAG AG milling circuits the design flexibility required to 3 SAG mill 8 – 15 ball charge Variable or moderate competency ore with the competency suiting the selected grind size high speed SAG mill 4 ball charge 90 Nc A cross between AG and SAG for
Table of ContentsComminution Circuit DescriptionMill Availability and MaintenanceAdvantages and DisadvantagesVariable Speed SAG Mills Motor Capability vs Mill Capability The single line grinding circuit at Bond Gold s Colosseum mine consists of variable speed drive semi autogenous SAG milling and secondary grinding with a fixed speed ball mill
Each SAG primary mill Boliden Allis operates with two 5 000 HP Ball Mills as secondary grinding stage The Electric Drive SIEMENS consists a 11 000 HP synchronous motor of variable speed General Description of the Drive The SAG Mill Drive is mainly formed by a 11 000 HP
So testwork was undertaken at the time into high speed horizontal stirred mill Figure 4 illustrates a typical IsaMill™ product distribution in open circuit at varying After the initial comminution stages of crushing and or SAG AG milling the
Many grinding mill owners choose a variable speed drive for their mill to cope The paper specifically describes SAG mills but the equations and principles
Sep 24 2018 The single line grinding circuit at Bond Gold 39 s Colosseum mine consists of variable speed drive semi autogenous SAG milling and secondary
201227 ensp 0183 ensp Variable time delay in process responses Solids flow Feeder Speed 600 400 200 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 50 40 30 20 10 0 Mintek Crushing Figures 8 and 9 on the right show results from a gold plant s SAG mill achieved with
For SAG 2 Siemens supplies two 8 pole high speed induction motors to replace the existing slip ring motors eliminating all brush or slip ring related outages and maintenance activities The four identical variable speed drives VSD operating all four mill motors are Sinamics Perfect Harmony GH180 units
2018510 ensp 0183 enspTECHNICAL AND COMMERCIAL BENEFITS OF GEARLESS MILL DRIVES FOR GRINDING APPLICATIONS M Ahrens ABB Switzerland J Gonser ABB Switzerland operating cost and reduce availability of ball and SAG mills Options for variable speed are DC motors energy recovery determining the mill size the need for variable speed and the
The engineering and process effects of choosing a motor design speed Many grinding mill owners choose a variable speed drive for their mill to cope with variations in ore hardness plant throughput and other process considerations
SINGLE STAGE SAG AG MILLING DESIGN ABSTRACT Single stage semi autogenous autogenous S AG milling has become a common design for a variety of ore 3 SAG mill 8 – 15 ball charge Variable or moderate competency ore with the competency suiting the selected grind size high speed SAG mill 4 ball charge 90 Nc A cross between AG
A common approach across these systems is to provide the mill operator with a SAG weight setpoint Mill feedrate and mill speed for mills equipped with variable speed drives are manipulated by the control system to control mill weight to this setpoint
2016105 ensp 0183 enspVariable Speed Appliions 23 Cement Process overview Pumps A device that raises transfers delivers or compresses fluids or that attenuates gases especially by suction or pressure or both Benefits l Increases output and performance of SAG mill – l l Cement
201879 ensp 0183 enspVariable 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
2015729 ensp 0183 enspor stopping the SAG mill Feed System Control Crushed ore is fed onto the feed conveyor using one or more variable speed feeders The feeders are loed under the ore stockpile or bins By running different feeder combinations the size distribution of the SAG mill feed can be regulated to some extent The feedrate
2 d4 TM Mill Drivesystem 7 MW 7 MW 14 MW 28 MW 7 MW 4 MW 7 MW 7 MW 7 MW 4 MW 7 MW 7 MW SAG mill 32 ft single drive The natural progression in gear pinion mill drives The QdX4TM Mill Drive provides the next step in the evolution of change in mill drive architecture while allowing the system to be built with components that are within current manufacturing capabilities
speed sag mill feed conveyor feed conveyor sag gatewaypreschoolorg 321 Primary FAG SAG Mill Circuit Ore is withdrawn from the conical stockpile via 2 of 4 apron feeders and delivered to the primary mill feed conveyor variable speed sag mill feed conveyorsHammer base Gold Fields St Ives SAG mill main feed conveyor with classification tower and hydrocyclone variable nature of the SAG mill
0 a crush forward configuration of the SAG mill scats 0 partial to full secondary crushing 0 variable speed drive upgrade of the SAG mill 0 lifter and grate design
world s first 12 8m diameter SAG mill equipped with a drive which starts the mill way to match mill speed to the needs of Research Report 2007 34 Low Voltage Ride Through
A control strategy recently implemented on a large variable speed SAG mill at MMG s Century Zinc operation in Australia is shown in the chart found on pg 32
ACS1000 variable speed drive increases output and performance of SAG mill The LaRonde mine in Canada is Agnico Eagle s flagship operation producing about 260 000 ounces of gold annually In order to run the motor and the SAG mill at the required load output the existing drive was replaced with ABB s ACS1000 variable speed drive
2010413 ensp 0183 enspIn this case mill speed is the primary manipulated variable used to control mill load While there is no generic control strategy for SAG milling there is a considerable amount of reusable engineering In contrast to an expert or black box system the control loop approach was built using standard blocks connected as shown
The variable speed RMD solutions offer the ability to minimize the wear of mechanical components of the mill As an example the impact of the balls on the liners of the mill can be avoided by reducing the rotation speed
For SAG 2 Siemens supplies two 8 pole high speed induction motors to replace the existing slip ring motors eliminating all brush or slip ring related outages and maintenance activities The four identical variable speed drives VSD operating all four mill motors are Sinamics Perfect Harmony GH180 units
2017712 ensp 0183 enspThe singlestage SAG mill circuit was shown to efficient operate ly on primary crushed Wallaby Deeps underground material With relatively coarse competent feed and a reasonable ball charge the variable speed SAG mill generated a product with sufficient fines content that the cyclones could manage without excessive recycle
In this case mill speed is the primary manipulated variable used to control mill load While there is no generic control strategy for SAG milling there is a considerable amount of reusable engineering In contrast to an expert or black box system the control loop approach was built using standard blocks connected as shown