(PDF) Influence of feed size on AG / SAG mill performance
and ag/sag mill response and provides examples of cases where feed size has been successfully manipulated. MEASUREMENT OF FEED SIZE Successful manipulation …
AG - Autogenous & SAG Semi-Autogenous Mill Design …
The SAG mill was sized with 746 kW to give a 25% contingency for power swings on the calculated power. The ball mill was sized at 1120 kW. Total installed power for comminution exceeded that required for conventional grinding by a factor of 1.163 (including secondary crushing).
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 ...
Modelling: Transfer size limits - SAGMILLING
The software uses the particular power model (Bond/Barratt, Morrell Mi, etc.) to determine what is the transfer size where the ratio of E SAG to E ball matches the ratio of mill power (1:1.5 in this example). This is the 'maximum efficiency' transfer size where the mills will both operate at full power.
Ø Effect of SAG Mill Feed Size Distribution and Ore ...
Ø Manipulation of SAG Mill Operating Parameters (eg. load, ball charge, speed and density) Ø Maximising Pebble Recycle Load and Crusher Interaction With the SAG Mill I-12 Ø Effect of SAG Mill Feed Size Distribution and Ore Variability Ø Mill liner design modifications, and Ø Circuit Design Considerations That Influenced Throughput
Size analysis diagram of cyclones' feed, underflow, and ...
Size analysis diagram of underscreen stream along with SAG mill feed is showed in Figure 6. Characteristics of the third sample and its comparison with plant design numbers (targets) could be ...
Industrial Grinding Estimation of Blended Ore from ...
AG/SAG mill feed, trommel screen undersize product (-5.00 +0.00 mm), ball mill discharge and cyclone feed, overflow and underflow have been conducted in order to characterize the particle size distribution in the products and to carry out mass balancing of grinding circuits.
What's the Difference Between SAG Mill and Ball Mill ...
The feed size is usually between 20-30mm and the product size is 0-3mm. Feed Both the autogenous grinding mill and the ball mill feed parts are welded with groove and embedded inner wear-resistant lining plate. As the sag mill does not contain grinding medium, the abrasion and impact on the equipment are relatively small.
Model:Amelunxen SGI - SAGMILLING
Amelunxen SGI Model. This is a model that estimates the specific energy consumption of a SAG or AG mill plus ball mill circuit using the equation by Amelunxen (2014) for E SAG and the classical Bond work index equation for E ball substituting CF ball in the place of the Rowland efficiency factors.. The model requires manual calibration factors for both equations (CF SAG and CF ball ...
Publications - SMC Testing
Influence Of Feed Size On AG/SAG Mill Performance Mapping Orebody Hardness Variability For Ag-SAG Crushing And HPGR Circuits Modelling And Simulation Techniques Applied For Optimisation Of Mine To Mill Operations And Case Studies Modelling The Influence On Power Draw Of The Slurry Phase In Autogenous (AG), Semi-Autogenous (SAG) And Ball Mills
SAG Mill Grinding Circuit Design
While critical-size could be of any dimension, it is most typically synonymous with pebble-crusher feed, with a size range of 13—75 mm. Critical-sized particles can result from a simple failure of a mill's breakage rates to exceed the breakage rate of incoming particles, and particles generated when breaking larger particles.
Energy Benchmarking - SMC Testing
A number of samples were taken from the SAG mill feed belt and subjected to SMC Tests and Bond ball mill work index tests. Note that the Bond tests were conducted using 150 microns as the closing screen size so that the final product size from the tests was similar …
Claim Case Study - Concordia University
The second conveyor, the SAG mill feed conveyor, originates at the base of the Coarse ore silo (85 feet) and continues into the new mill building (45 feet) where it discharges into the SAG mill. About 95 feet of this conveyor is outside and is fully enclosed in a steel structure.
Gold Fields Granny Smith Grinding Circuit: A Metallurgist ...
After closed-circuit secondary crushing, the SAG mill feed 80% passing (F80) size was 25 mm to 30 mm. Installed grinding power is split equally between the two mills with the SAG mill fitted with a variable speed drive (VSD). SAG discharge screen oversize ('pebbles' or 'scats') was …
Grinding Mill Computer Model
Fo - Optimum Feed Size for rod mills F o W r =16 000 ... size and power relationships For SAG mills the equation becomes Power=(5.6115+%balls*0.1438)*D24. 6* L Mill Critical speed Crit Crit D = 42.3 n - revs per min nC= s*Crit Cs is the fraction of the critical speed
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.
Mine-to-Mill: The influence of feed size on AG/SAG milling ...
In this presentation an historical perspective of the origins of Mine-to-Mill is described and is followed by a discussion of how AG/SAG feed size affects throughput and specific energy and the factors that in turn influence AG/SAG feed size, such as ore hardness, Run of Mine (RoM) size distribution and crusher operation (both primary and secondary).
SAGDesign Test | Starkey and Associates Inc.
The SAG mill pinion energy, W SDT (kWh/t) and SAG discharge Bond ball mill work index, S d-BWI (kWh/t), are then used to calculate the total energy to grind the ore from 80% passing 152 mm to 80% passing the client specified final product size P 80.This information, along with the ore specific gravity, is used to calculate necessary mill sizes and motor power in industrial applications.
IMPROVEMENTS IN SAG MILL THROUGHPUT FROM FINER …
1 IMPROVEMENTS IN SAG MILL THROUGHPUT FROM FINER FEED SIZE AT THE NEWMONT AHAFO OPERATION *Adrian Dance1, Sonny Mwansa2, Walter Valery 2, George Amonoo3 and Bryon Bisiaux3 1SRK Consulting (Canada) Inc 22nd Floor, 1066 West …
The appropriateness of the transfer size in AG and SAG ...
In his approach the total specific energy of the entire AG/SAG circuit is firstly predicted using the SAG mill feed F80 and the ball mill cyclone overflow P80. ... that the feed particle size has ...
Major Mines & Projects | Rainy River Mine
The SAG mill feed conveyor is equipped with a weightometer to monitor and control the SAG mill feed rate. Primary grinding – SAG mill The SAG mill is an 11.0 m diameter by 6.1 m long grate discharge mill with a dual pinion drive consisting of two 7,500 kW motors with VFDs. The surveyed mill feed is a F80 of 46 mm and the discharge transfer ...
Design for sampling—preliminary exploration
photos to be taken to monitor feed size variation during testing. For new plant design it is strongly recommended that a camera imaging system is installed to give an online sample of feed size— especially for AG/SAG mills. As both valuable minerals and moisture tend to be concentrated into finer size fractions, it is useful to measure
(PDF) DESIGN AND OPERATION OF VERTIMILL® FOR SECONDARY ...
Morrell and Valery Jnr., W. (2001) Influence of Feed Size on AG/SAG Mill Performance. SAG2001 - SAG mill circuit. International Conference on Autogenous and Semiautogenous
Power-based modelling of single-stage AG and SAG mill …
P80 is the SAG hydrocyclone overflow 80% passing size, µm F80 is the milling circuit feed 80% passing size, µm, fSAG is a calibration parameter for pebble crushing and/or fine feed (typically 1.0 for 80% passing six inch mill feed and when no pebble crusher is present). WiBM is …
Grinding Circuit Final Grind Control at Agnico Eagle ...
size depending on the required mill feed rate and ore hardness. Figure 3 – Meadowbank milling flowsheet . Crushed ore is conveyed to a covered stockpile with an 8,500 t live capacity. Two variable frequency drive pron feeders reclaima the stockpiled material to a conveyer belt feeding the SAG mill in the primary grinding circuit.
GMSG GUIDELINE: DETERMINING THE BOND EFFICIENCY …
mills, and use a rod mill feed size (F80) of 16,000 m and a rod mill µ product size of 1,000 m . Also note µ that in order for no correction factor for ball mill product fineness to apply, the ball mill circuit P80 should be no less than approximately 70 µm (See reference by Bond, 1962).
Optimization and Performance of Grinding Circuits: The ...
targets by lowering the throughput. Further, the SAG mill circuit was characterized by fluctuating feed size of between x. F, 80 =102 to 185 mm. A need for control of the feed size as well as blending ratios was recommended for an efficient operation in terms of throughput and final product size. This could be achieved through closer monitoring of
SAG Mill - goldcilplant
The capacity of the SAG mill is related to lots of factors such as feed size, size distribution, discharge size and grindability, etc., and it should be confirmed according to the actual situation. SM40*14'——means it is a dry mill.
Chapter - M MODELLING, SIMULATION, OPTIMIZATION
To sample SAG mill fresh feed, belt conveyor was stopped and a sample was taken by removing material over a two-meter length. Operating condition ... Mill fresh feed particle size distribution was also determined using rod screens and laboratory screens. Weight of …
Autogenous and Semi-Autogenous Mills - ScienceDirect
The feed to high aspect AG/SAG mills are usually preferred from gyratory crushers, while the feed to low aspect mills are preferred from jaw crushers. Depending on the set, the maximum size of the particles discharged from gyratory crushers is about 300 mm and from jaw crushers is about 180–100 mm; thus, the optimum feed size may be taken to ...