(PDF) RealTime Simulation and Control of a SAG .
eight years in a large v ariablespeed SAG mill at MMG''s Century Zinc operation in Australia and controls the mill with minimal operator involvemen t over 95% of the time
eight years in a large v ariablespeed SAG mill at MMG''s Century Zinc operation in Australia and controls the mill with minimal operator involvemen t over 95% of the time
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). This was deemed to be the most cost effective solution for the required speed range of 70 to ...
Low SAG Mill Critical Speed Grinding Classification . 202068 · If you have to reduce the SAG mill speed because of avoiding liner breakage, maybe it''s better to modify the shell lifter design. Low speed may cause decreasing capacity, higher steel ball and liner wear rate. D80 of SAG mill may be finer because of more cascading action ...
Figure Simplified calculation of the torque required to turn a mill. RI FULWLFDO VSHHG 3RZHU Figure 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 ...
SAG Mill 2 Ball Mill Simulations of the Mill Power Effect on the Throughput Conclusions. Introduction At the moment, the conventional grinding technologies of SAG and Ball Mills are power inefficient, they use from 35% of the total of the energy consumed. Some researchers have indicated that the maximum grinding efficiency of grinding is limited to 3 about 20% using intra particle fracture ...
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 RPM with a range of +50% / 10%
AG/SAG circuits. Its accuracy is demonstrated using data from a wide range of plants. The DW i has been found to be correlated to the point load index, which makes it valuable for MinetoMill projects. It is also correlated with the operating work index of HPGR circuits and in conjunction with pilot and/or
A control strategy recently implemented on a large variablespeed SAG mill at MMG''s Century Zinc operation in Australia is shown in the chart (found on pg. 32). 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 ...
The "Critical Speed" for a grinding mill is defined as the rotational speed where centrifugal forces equal gravitational forces at the mill shell''s inside surface. This is the rotational speed where balls will not fall away from the mill''s shell. Mill Inside Diameter: Enter the mill diameter inside the shell (excluding liners). Most mill sizes are reported by vendors are outside the ...
OPTIMAL SAG MILL CONTROL USING VIBRATION DIGITAL SIGNAL PROCESSING TECHNIQUES *Karl S. Gugel, Digital Control Lab, 4647 NW 6th St. Gainesville, Florida USA 32609 (*Corresponding author: ) VANCOUVER 2015 2 | P a g e 2/23/2017 OPTIMAL SAG MILL CONTROL USING VIBRATION DIGITAL SIGNAL PROCESSING .
01/01/2016· The mill speed is 70% of the critical speed. A high aspect SAG mill had an ID of m and the length measured m along the central line. The mill was charged with ore having an of and the load was 40% of the mill volume. The grinding media steel balls occupied % of the mill volume. The mill was rotated at 75% of its ...
factor of that accounts for the difference in grinding efficiency of a SAG mill versus a ball mill. The original Barratt papers do not specify values to use for PC and PR, but we can use the same values as Table 1 of 10 000 µm and 2100 µm, respectively. The value T80 is the "synthetic" transfer size between the SAG mill and ball mill ...
SAG Mill power draw models are used in mill design and grinding circuit modelling to predict how muc h pow er wi... [↓ read more ↓] Alex Doll: modelling: A simple estimation method of materials handling specific energy consumption in HPGR circuits [] Multistage crushing plants, including high pressure grinding roll (HPGR) circuits, require more mat erial s han... [↓ read more ↓] Alex ...
The ball mill speed is reduced so that the secondary power draw is exactly what is necessary to achieve the target circuit P 80. Secondary mill limited condition . The software generates a "Secondary mill limited" warning when the ratio of primary:secondary power available has too much primary power (or insufficient secondary power). This means either your SAG mills are too big (or you have ...
These equations are used by SMCC Pty Ltd to estimate the specific energy of AG/SAG mills under all normal operating conditions, eg ball load, mill speed, feed size and ore hardness and for all ...
Percent of critical speed, operating range, [%] 73% Ball loading, operating, [% v/v] 1215% Ball loading, max, [% v/v] 20% Mill power transmission loss, estimated, [%] 5% Feed slurry percent solids, [%] 65% New feed rate operating average, [DTPH] 2265DTPH Maximum motor power, [kW] kW Table 1. General Characteristics of SAG1 and SAG2 Process Control The two main variables for controlling ...
During normal operation the mill speed tends to vary with mill charge. 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 ...
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). Get Price
19/10/2020· The SAG Mill is a machine added by Ender uses Micro Infinity (µI) to grind (or mill) items into their crushed variants, like Ores into SAG Mill has four output slots; recipes can have 14 different outputs, with different chances of obtaining those outputs. Uniquely, the SAG Mill can use Grinding Balls made from various materials to increase energy efficiency (resulting in ...
With variances in mill ore feed rate, mill speed and slurry density, critical impacts can occur in your SAG mill. The speed at which these variances are adjusted for is thus crucial for minimizing damage and optimizing liner life. Every second counts, and adjusting these parameters within seconds can have a significant effect on the wear of your SAG mill, which will effect on your bottom line.
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).
wide speed range allow advanced optimization of the process. The design of such large mill drive systems requires modern simulation tools to verify the system behavior. An optimized design must take into account the mechatronic interaction between all individual mechanical and electrical components. Calculation methods and related design targets must be defined in a very early stage of the ...
the mill speed as a fraction of the critical speed, ϕC, can be observed by plotting the process power and torque draw superimposed on the relevant motor capability curve. Such plots for an example mill, the SAG mill at Cadia (described by Dunne et al., 2001) is shown in Figure 3.
Mill Speed . No matter how large or small a mill, ball mill, ceramic lined mill, pebble mill, jar mill or laboratory jar rolling mill, its rotational speed is important to proper and efficient mill operation. Too low a speed and little energy is imparted on the product. Too fast and inefficient media movement (known as cataracting) will generate high impact but also greatly increase mill wear ...