In my experience, SAG Mills are normally variable speed, and Ball Mills are normally fixed speed. There are multiple ways to provide variable speed, the common ones are WRIM+LRS+SER or SCIM+VSD, the top of the range is gearless mill drives.
SAG is an acronym for semi-autogenous grinding. SAG mills are autogenous mills that also use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor.
at the kiln or mill shell at normal operating speed when the main drive is operating. • Full load running torque required at the kiln or mill shell at inching operating speed. Typically this is set at 120% of main drive operating torque. • The desired output speed at the shell. Usually this is targeted at 0.1 RPM with a range of +50% / -10%
Mill Steel Charge Volume Calculation. Previous Next. View Larger Image. We can calculate the steel charge volume of a ball or rod mill and express it as the % of the volume within the liners that is filled with grinding media. While the mill is stopped, the charge volume can be gotten by measuring the diameter inside the liners and the distance ...
Jun 19, 2015· Ball Mill Critical Speed & Working Principle ... The only assumptions required for determination of the single ball trajectory are a coefficient of friction between the ball and mill lining, and ...
the fundamental requirements of your operation. We can determine the most suitable changes to implement in order to reach your production goals. Applications • AG and SAG mills • Ball and FGD mills • Pebble and rod mills • Multi-compartment mills • Rotary kilns and dryers • Mixers and other equipment A complete range of gear and ...
Model Predictive Control for SAG Milling in Minerals Processing | 5 Model Predictive Control on a SAG Mill and Ball Mills The solution for the SAG Mill is an adaptive controller which controls mill load using direct mill weight measurement or indirectly from bearing oil pressure.
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Figure 8.3 Simplified calculation of the torque required to turn a mill. RI FULWLFDO VSHHG 3RZHU Figure 8.4 The effect of mill speed on the power drawn by a rotating mill. The liner profile and the stickiness of the pulp in the mill can have a significant effect on the actual critical velocity. Mills usually operate in the range 65 - 82% of ...
Required Tool : Fused Quartz is a utility block used in crafting various blocks introduced by EnderIO mod. It can also be used instead of Hardened Glass in Thermal Expansion recipes. Recipe ... Alloy Smelter • Crafter • Painting Machine • SAG Mill • Slice ...
DESIGN OF AG/SAG MILL CIRCUITS USING THE SMC TEST. ... mill speed, feed size and ore ... Predicting the Overall Specific Energy Requirements of AG/SAG, Ball Mill .
Table of ContentsSAG Mill ChargeSAG Mill Horsepower — Drive PowerOre Testing for AG & SAG Grinding Mill Design Mill Sizing: After laboratory and pilot plant testing confirm the feasibility of autogenous or semi-autogenous grinding, it can be used to establish the exact grinding circuit and mill size. In the pilot plant tests, the tare power of the pilot plant mills should be determined ...
The motor power draw required to turn a mill from rest to the operating speed includes the energy required for the initial starting torque and mechanical arrangements to rotate the mill. It is generally accepted that practical mill power (PM ) is a function of mill capacity and diameter, i.e.,P M = Mill Constant * (Mill Diameter ) n
SAG is an acronym for Semi-Autogenous Grinding. SAG mills are autogenous mills but use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor.
According to available literature, the operating speeds of AG mills are much higher than conventional tumbling mills and are in the range of 80–85% of the critical speed. SAG mills of comparable size but containing say 10% ball charge (in addition to the rocks), normally, operate between 70 and 75% of the critical speed.
part inventory. If required, ring motor drives can be fitted to shell-supported grinding mills up to the largest sizes. SAG/ball mill circuit incorporating pebble crushers and a POLYCOM® high-pressure grinding roll. SAG and ball mill for gold ore grinding. One of three SAG mills with 9.75 m diameter and 2 x 4000 kW drive power. These mills
SAG Mill Control at Northparkes Page: 1 SAG Mill Control at Northparkes Mines (Not So Hard After All) A. J. Thornton, Principal Process Control Engineer1 Tom Pethybridge, Production Superintendent – OPD2 Tom Rivett, Process Control Engineer2 Richard Dunn, Metallurgical Superintendent2 1.
Oct 12, 2017· The SAG mills are generally used in pre-processing of any type of material in grinding process. SAG mills are also known as first stage grinders. These heavy output SAG mills are usually powered by electricity. As requirements and needs in grinding field are enhanced. Improved SAG mills came in trend, which gives highly rated production.
The required process power is divided into circuits and numbers of mills within a circuit, followed by the selection of the mill sizes to fulfill the requirements. The optimal drive type can only be selected after determining the mill size, the need for variable speed and the .
The model assumes all SAG mills are variable-speed; if a fixed-speed mill encounters this condition, it will completely grind out and operators will probably be forced to stop the SAG mill. Pick your mills sizes to avoid secondary mill limited conditions. This transfer size is .
Modelling SAG milling power and specific energy consumption including the feed percentage of intermediate size particles ... the SAG mill critical speed; Pc = SAG mill power consumption (kW); % 600 +100 = % of the fresh feed in the size range 152 +25 mm. M. Silva, A. Casali/Minerals Engineering 70 (2015) 156–161 157.
May 02, 2018· A variable speed drive can generally provide inching or creeping capabilities — which eliminates the need for a separate inching drive — as long as the motor is capable of operating within the speed range required for inching.
the correct power required to grind ore in a SAG mill, by developing ore hardness variability functions for the ore body to be mined. This paper describes the next step in the SAG design process, which is choosing a SAG mill to accomplish the required specified design performance.
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 Hyper-Synchronous drive Slip Energy Recovery (SER), in conjunction with Wound Rotor Induction motors (WRIM).