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A Nonlinear Process Monitoring Appro ach K.S . McClure*, R .B. Gopaluni** ... Abstract: Detecting the onset of overloading in a semi -autogenous grinding (SAG) mill is a challenging task for operators to perform due to the complex and nonlinear nature of an overload. ... However, mill power does not have a consistently repeatable behaviour ...

Mill power Usually, plant operators use mill power readings as an indicator of ball filling degree and, often, try to keep it at the maximum level. It is well known that the mill absorbed power depends on operating parameters other than ball level, such as pulp density and liner configuration. Figure 2 shows that there is no linear relation between

reference and relative power draw formulas presented here will provide you the best overall characterization of the power draw of your SAG mill. 1-1: The Basic or Reference SAG Mill Power Draw Formula The following formula can be used to calculate SAG mill power draw as a function of mill operating conditions.

Mill Power Draw Models. The mill power draw models are used to predict how much power will be consumed by a particular type of mill, mill geometry and set of mill operating conditions. This power is transferred to the ore and used to predict the throughput when combined with the specific energy consumption models.

The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills.

Modelling SAG milling power and specific energy consumption including the feed percentage of intermediate size particles ... ables with the dependent variables SAG mill power and specific energy, to assure models with fixed parameters. ... a significant portion of the power draw.

Kinross – Round Mountain SAG Mill Adaptive Control. In summary, by using the KnowledgeScape SAG mill adaptive control system (GrindingExpert™), we were able to increase production, increase power draw through increasing the grinding efficiency of the mill. These benefits easily justify the low cost of the system and system maintenance.

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. A SAG mill with a 44' (13.4m) diameter and a power of 35 MW (47,000 HP) has been designed. Attrition between grinding balls and ore particles causes grinding of finer particles. SAG mills are characterized by their ...

The no load power is a measure of some of the power losses in the gears, bearings and electrical components and is the gross power draw of the mill when empty, obtained either during commissioning of the mill or when ground out for a mill reline. Morrell [13] developed an empirical expression for the no load power draw of ball, SAG and AG mills as

Jan 30, 2019· Mill power models have been used in a variety of ways in industrial practice since power directly equates to throughput and fineness of ground product. We first start with Hogg-Fuerstenau Power Model and show how this model successfully predicted the power draw of many grinding mills in several mining operations.

SAG mill power draw models are used in mill design and grinding circuit modeling to predict how much power will be consumed by a particular mill geometry and operating configuration. This paper will compare sAG mill models by Morrell, Loveday (using 'Power Numbers' published by Barratt) and Austin against several published mill surveys.

predictions made by two published mill power draw models for SAG mills (Austin's SAG model and Morrell's C-model). A third model (Hogg and Fuerstenau) is fit to each survey and the principal fitting parameter is tabulated. Power measurement The nature of electrical and mechanical networks is that power is lost to various types of inefficiency as

It follows that SAG mill process control systems that target maximum SAG motor power will not necessarily result in the maximum milling rate. Instead, SAG mill process control systems that aim to maximize SAG mill federate should target operation at the optimal volumetric mill filling for .

Two new SAG milling models are developed in this work, able to predict power or specific energy consumption, including the usual design variables such as mill size; balls charge level, solids concentration in the SAG mill feed and % of critical speed, but adding a .

2. A SAG mill operates with a 10,000 hp motor. Typical power draw is 80% of maximum. The 80 percent passing feed size to the mill is 6 inches and the mill discharge has an 80 percent passing size of 2.3 mm. Calculate the Operating Work Index for this mill if the feed tonnage rate is 1175 tonnes per hour.

SINGLE STAGE SAG/AG MILLING DESIGN Brian Putland 1, ... stability associated with the constant power draw and fine media in the ball mill. Lack of grinding media in ... This puts the application in the realm of a single mill with gearless drive. xPower demand of more than 28 MW.

It is imperative to ensure the efficient removal of both slurry and coarse pebbles (critical size) in order to ensure the efficient operation of AG/SAG mills. Elimination of the above mentioned material transport problems will allow the mill to respond truly in terms of power draw for changes in mill load which depends on feed ore characteristics.

SAG mill design CDM Consulting used to test Rocky DEM power draw Empirical Model Rocky DEM Model Figure 1 - Morrell C-model for mill power draw Rocky calculations for power draw were shown to accurately replicate Morrell's C-model for power draw, an increasingly critical component in mill .

If the mill feed setpoint is changed, then the actual feed rate needs to stabilise at the new target in a short period of time. The feed rate setpoint can then be tied into a SAG mill power optimisation strategy. SAG mill discharge control is quite involved due to few interactive variables, such as mill discharge sump level, classification ...

For the mill with higher mill load and lower speed, the power draw of the mill differed slightly for the different lifters with the same face angles of 20o. Rail lifter drew higher mill power and lower power for Hi-Lo lifter. The Hi-Lo lifter relatively indicated improvement in the energy efficiency of the mill approximately 22%.

operating at 90% of its maximum power. The combined power draw of the SAG mill and ball mill was 8658 kW, which caused partial over-grinding. From experience in processing plants outside of China, the power rating of the ball mill should be higher than that of the SAG mill [5]. The pebble crusher had an over-powered configuration.

of the energy required by a SAG mill. Put another way, the SAG mill energy required according to this statement, is 2.5 times more than the Ab value to produce the same degree of particle breakage. There is a speci fi c gravity factor that affects AG/SAG power draw. The lighter material, in the 2.5 specifi c .

SAG mills • Determination of your SAG mill's power draw characteristics. • SAG Mill Steel Charge Estimation tool provides an estimate of the percent steel in the charge of your SAG mill based on the power draw and the total charge volume. • Ball impact energy chart to determine the impact energy of balls as a function of mill diameters.

Using Monte Carlo simulation showed that the mean power draw of the Sarcheshmeh SAG mill is about 9349.75 kW with a standard deviation of 983.2 kW, with the highest frequency occurring between ...
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