Feb 01, 1999 Estimating the power draw of a ball mill is of great importance from both operational and control standpoints. There are many factors that affect the power draw, and its prediction is particularly difficult in an operating plant. The important factors that affect power draw are the mill dimensions and operating parameters. Although mill dimensions remain the same for any given mill, the ...
Nov 01, 1998 The average power is 3 105 W per meter of mill length. This gives a total power draw for a typical 7 m mill of 2.1 MW. This compares well with a typical lrnotor power of 3.3MW. Superimposed on this average power draw are irregular high frequency fluctuations of 130 of the mean, reflecting the highly impulsive and unsteady flow of the charge.
Effective mill power draw Ball mill specific grinding rate Ball mill grinding efficiency The circuit output is defined as the production rate of fines by the circuit. It is calculated from three values 1. The dry ore feed rate to the circuit th. 2. The fines in the circuit feed. 3. The fines in the circuit product.
Ball Mill Motor Power Draw Sizing and Design Formula. Apr 05, 2018 The following equation is used to determine the power that wet grinding overflow ball mills should draw. For mills larger than 3.3 meters 10 feet diameter inside liners, the top size of the balls used affects the power drawn by the mill. This is called the ball size factor S.
However, the trend is clear in that as ball mill feedrate increases the power draw falls. As can be seen the average power draw is about 12.5 MW and occurs at a feedrate new feed plus recy cle of about 6000 thr. Over a wide range of feedrates about the mean value of 6000 tph the power draw varies by only - 5. Of note
Nov 02, 2014 3. Experimental Procedure The DEM simulated mill was configured to match the environment inside the laboratory scale ball mill at Mintek. The DEM parameters used for the simulations are given in Table 3.1. 5. Discussion Fig. 4.1 shows that the mill power draw increased gradually as the lifter face angle decreased from 90 to 45.
Metso Outotec has designed, manufactured and installed over 8,000 ball and pebble mills all over the world for a wide range of applications. Some of those applications are grate discharge, peripheral discharge, dry grinding, special length to diameter ratio, high temperature milling oprations and more. All equipment adheres to the applicable ...
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
mill is the energy consumption. The power supplied to the mill is used primarily to lift the load medium and charge. Additional power is required to keep the mill rotating. 8.1.3 Power drawn by ball, semi-autogenous and autogenous mills A simplified picture of the mill load is shown in Figure 8.3 Ad this can be used to establish the essential ...
Jul 21, 2006 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. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size.
Jul 25, 2016 Discrete element method simulations of a 15-scale laboratory ball mill are presented in this paper to study the influence of the contact parameters on the charge motion and the power draw. The position density limit is introduced as an efficient mathematical tool to describe and to compare the macroscopic charge motion in different scenarios, i.a. with different values of the contact ...
ball mill and grinding circuit preparation for start-up put density controller on manual mode and set the output to 20. most of these variables are monitored in the mill control room, however, the operator is also required to sample the mill power draw by looking at the mill power draw recorder.
power draw of AGSAG and ball mills. Note that the ball mill operating work index is applied only on the portion that needs the additional grinding Q2, which renders to the AGSAG mill the credit for the fraction of the material that had been already ground to final product
at a constant mill filling, the power draw was changed with changing the ball size distribution and for all mill fillings the maximum power draw occurred when the fraction of small balls was between 30-40. The effect of ball size distribution increased with increasing mill filling and for the mill filling of
ROD AND BALL MILL POWER DRAW OBJECTIVES This module will introduce you to rod and ball mill power draw . At the end of this module, you will be able to Differentiate between energy consumed and power drawn by grinding mills. Calculate the approximate mill power draw of operating rod mills and ball mills given basic design and ...
Dec 12, 2016 Now we much select a Ball Mill that will draw this power. The ball mill motor power requirement calculated above as 1400 HP is the power that must be applied at the mill
A power analyser was utilized to measure mill power. Increase in mill speed and ball filling leads to a remarkable increase in the amount of the power. Preliminary results show that there is a definite trend between the power and the slurry filling U. Mill power draw is maximum at slurry concentration 6070 and slurry filling 0.84.
Jun 23, 2020 Estimates of the increases in power draw possible with grate discharge ball mills range from 10 to 20, according to mill size and other operating parameters. The figures from pilot tests and some operating sites are even higher, up to 25 more power draw.
Ball mill power draw predicted from the Denver slide rule, kW 0 200 400 600 Calculated ball-mill power draw from the m odel derived, kW Data compared Line yx Fig. 2. Comparison of the ball mill power draw from the Denver slide rule and the proposed model. Dashed line corresponds to yx.
Results show the mill ball charge shoulder angle is strongly affected by the liner lifters face angle and that Morrells Model C could be improved by including a correction parameter that reflects the power draw of a mill along the service life of its liner. The correction parameter is to reflect the effect of wear on the shoulder angle.
Motor power and media addition. The power drawn by the Vertimill motor is required to establish the grinding rate. Motor power should be measured using corrected power. As the grinding media wears fine enough to be carried out by the uprising velocity in the mill, the total media charge will diminish, and the power draw will decrease.
close to the maximum mill power draw. The power-load relationship is highly non-linear and shifts around as the ore and steel loadliner changes. Traditional control and modeling techniques can therefore not be used. Mintek has developed a Power Optimiser that Continuously seeks for the optimum mill
Ball Mill Gearbox Features. Mill drive gearboxes are designed to complement the girth gear to deliver cost effectiveness across the entire system. Gear cases machined from rigid housings to ensure optimum shaft alignment, reduced noise and dynamic deflections. Simple lubrication and cooling allows the system to operate at various speeds ...
randpicBest way to determine the ball-to-powder ratio in ball ...The maximum power draw in ball mill is when ball bed is 35-40 by volume in whole empty mill volume. Considering that ball bed has a porosity of 40 , the actual ball volume is consi
Effect of ball diameter size on mill power draw The mill power draw for each mill run was determined from the voltage required by the mill motor average voltage and torque. To take a closer look at the relationship between the power draw and the ball diameter, Figure 4 below was plotted using data from 4 mill
Dec 02, 2016 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 conguration. The installed power draw of 630 kW
the mill with ore up to the point where maximum mill power draw is registered. At maximum power draw it is assumed that the void spaces within the ball load are filled with ore particles and that the charge is well mixed. In order to conduct the study an inductive proximity probe was used to measure the dynamics of the load behaviour.
Dec 17, 2018 Net power draw for an industrial mill is calculated by one of the methods as N k x F x n x x D x a 21 Where, N Net power kW k Constant for unit conversion F Quantity ball charge, Ton and mill filling about 28 35 of available millvolume n Mill rotation, rpm 12.
investigate the power draw, load behaviour and impact energy profile of an experimental ball mill under different milling conditions. The variables considered were mill rotational speed critical speed, ball size, and lifter face angle. The DEM simulation results indicated that the grinding efficiency would be
ball mill as a function of mills power draw or investigation on the ball filling ratio under batch wet conditions, due to load density alters 2, 3. In addition it is to be noted that too large or too small mills load filling could conduct to unproductive operating conditions, or to an aggressive ...
We perform power calculations for maximum power draw for Ball Mill liners for maximum throughput. Process Review. Study of slurry flow from SAGAG mills for slurry pool or slurry flow back issues for mill throughput improvement. Study of slurry flow from grates to improve the grate wear life.
The discrete element method for the simulation of ball determine the mill power draw of each size. The model uses a simpli- mills. Appl. Math. Model. 16 11, 598604. ed, probability based form of the current approach to determine the Morell, S., 1992. Prediction of grinding-mill power. Transactions of the Institution of Mining and ...
Jun 19, 2015 A motor with around 1400 Horse Power is calculated needed for the designed task. Now we much select a Ball Mill that will draw this power. The ball mill motor
Apr 01, 1999 The calculated power draft is maximum at about 50 ball load. According to Eq. 1, mill power is a function of ball mass M b and the distance between mill
Oct 19, 2015 Ball Mill Motor Power Draw Sizing and Design Formula. The following equation is used to determine the power that wet grinding overflow ball mills should draw.