the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling and operators had to learn more. However, the power consumption is 0.3-1.3 kWh / ton lower than before. The …
close to the maximum mill power draw. The power-load relationship ... Figures 8 and 9 on the right show results from a gold plant's SAG mill achieved with MillStar's Segregated Ore Feed Controller ... Mill Power Optimisation results for Case Study 2 Figure 9: Feed Control Distribution for Case Study 2.
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The SAG mill power draw model of Austin (using the cali-bration by Doll, 2013) is used to predict the process power draw at the mill shell, Pshell, and the efficiency losses for the drive's mechanical components based on Doll (2012) are used to determine the motor output power, P. The effect of varying the mill speed as a fraction of the critical
You must manually check the motor's tent diagram to confirm that the predicted power draw is actually within the motor's capability at the indicated speed. Liner and grate design. The design of mill liners and SAG mill discharge grates will have a large effect on how …
Analysis of Power Draw in Ball Mills by the Discrete Element Method. Abstract Ball mills, like other comminution devices, consume large amounts of energy. Mill operators often have to assess the power draft of mills for an entirely different set of operating conditions or for a reconfigured circuit. It is shown that the power draft can be ...
The model output variables are: power-draw, load level, ball load, mineral discharge rate and size distribution, water discharge rate, ball throughput, bearing pressure, pebble throughput, and toe and shoulder angles of the internal load. 2.1 SAG mill model The particles fed to the mill are ground in the milling chamber and subsequently
Figure 5.11 Power variation with mill speed for different media shapes (J=15%).86 Figure 5.12 Power variation with mill speed for different media shapes (J=20%).87 Figure 5.13 Power variation with mill speed for different media shapes (J=25%).87 Figure 5.14 Variation of mill power draw with mill filling, J (cylpebs media)…..88
The attributes of the Ok Tedi SAG mills . that are used by the expert system are power draw, lift pressure, motor temperature and recycle tonnage. Fresh feed tonnage and feed density are the manipulated variables. Set point changes in tonnage or SAG mill feed density are returned to the DCS PID controllers. Fuzzy sets are defined for all the
where two SAG mill power models are developed. The first model calculates the mill power draw by combining several individual data-driven algorithms. The second model uses historical data to forecast the mill power draw in advance. These data-driven methods can make high
However, from experience gained with single stage AG/SAG mills it became clear that even grate discharge mills can accumulate slurry at the toe of the charge and this can considerably affect power draw depending on the extent of the slurry pool (Morrell, 1989, Morrell and Kojovic, 1996). Hence it can be concluded that the extent of the slurry ...
The SAG mill power draw model of Austin (using the calibration by Doll, 2013) is used to predict the process power draw at the mill shell, Pshell, and the efficiency losses for the drive's mechanical components based on Doll (2012) are used to determine the motor output power, P. The effect of varying
The modeling and simulation of semiautogenous (SAG) mills have been widely used in the design and optimization of mill performance in terms of its power draw, processing capacity and product size distribution. However, these models are solved under steady approximation and do not provide any information on mill charge distribution in real time. This paper attempts to characterize …
SAG mills are a key asset for mineral processing operations as one of the critical stages of extracting mineral out of ore, and their continued stable operation is central to productivity, the JKMRC says. ... predicting mill filling can increase operators' confidence in running the mill at a higher average filling and power draw, thereby ...
SAG Mill Testing - An Overview of the Test Procedures Available to Characterize Ore Grindability : SUMMARY... power draw, especially if the AG/SAG mill is designed for a low steel charge. One other interesting feature of the drop- weight test procedure is that …
A 35% decrease in the SAG mill power draw from 3,908 HP to 2,526 HP (2,915 kW to 1,884 kW) was recorded. This equates to a 47% decrease in SAG unit energy consumption from 8.98 kWh/ton to 4.74 kWh/ton. A 11% decrease in SAG mill speed was …
The ball mill motor power requirement calculated above as 1400 HP is the power that must be applied at the mill drive in order to grind the tonnage of feed from one size distribution. The following shows how the size or select the matching mill required to draw this power is calculated from known tables 'the old fashion way'.
product fractions, specific power draw, and mill performance. Therein, load density and ball filling percentage in semi-autogenous mill and its effect on the mills power draw is of great value. There exist several ways to calculating ball filling such as drawing out …
Approximate mill diameter is derived from: Power =5.*6115 DL24. 6* La= * D where a is the aspect ratio L/D derived from a regression equation on 25 manufacturers' mill 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 ...
power draw. The most frequently used power-based methodologies for calculating energy requirements for comminution circuits using AG/SAG mills are concisely presented in the following section. This paper describes the Orway Mineral Consultants (OMC) approach determining power requirements for thto e
Optimising SAG mills • Objective – Optimised load – Increased liner life – Increased throughput / flowrate – Optimise power draw = increase throughput • Limitations – Structural load limit – Noise impact limit • Restricted by shell liner design Lifters + liners = protects the shell from wear Charge (mill load) = rocks + …
SAG Mill Power. SAG milling can be optimised to achieve maximum breakage and throughput (or any other number of objectives). The relationships between the key variables are highly non-linear and shift as the ore hardness, steel load and liner conditions change.
In semi-autogenous grinding (SAG), the grinding mill inventory, (i.e. volume of total charge, volume of ball charge, etc.) is important in determining the optimum operating condition for maximum production (tph), minimum specific energy (kwh/t) or lowest cost ($/t). A two-dimensional graphical method is presented for determining the actual ball charge within the total charge when …
I have an AccuPath CNC mill with power draw bar and would really like to find a quicker way to change tools without having to go through the Z-axis setup every time. 12-31-2007, 11:30 PM #2. Mr. O. View Profile View Forum Posts Cast Iron Join Date …
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 …
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.
SAG mill power draw models are used in mill design and grinding circuit modelling to predict how much power will be consumed by a particular mill geometry and operating configuration. The importance of conducting surveys suited to model calibration will be highlighted because the review of
Tega Soft (Discrete Element Method) :Simulate Mill Power draw, Power vs. Impact spectra & 3D-charge motion in a grinding mill. Used for optimizing mill lining design. Application: Ball …
SAG Mill power draw models are used in mill design and grinding circuit modelling 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.
SAG mills have a higher installed power density for a given plant footprint relative to AC mills. With the combination of finer grind and a lower installed power density (based on the lower density of the mill charge), a typical AG mill has a lower throughput, a …
predicted. Slurry pooling causes the power draw in AG and SAG mills to be lower than a mill without a slurry pool. This phenomenon results in overflow mills usually drawing less power than grate discharge mills that are operating without a slurry pool. This is because by definition overflow mills operate all of the time with a slurry pool.
The first one is the Mines Constancia SAG mill of size 36 × 26.5 ft. The mill is operating at 72% critical speed and 26% mill charge volume. The mill is fitted with trapezoid-shaped high and low lifters. The operating power draw was reported to as between 13.7 and 15.7 MW.
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. The installed power draw of 630 kW