SAG Mill Ball Sizing

With high aspect ratio SAG mills total charge to ball charge ratio should be greater than 2 (up to 2.5) for a coarse mill feed (say F80 > 110 mm). If the mill feed size is fine, say 50 mm or 30 mm, then you are looking at a total charge to ball charge ratio of about 1.5-1.6.

sag mill power calculations

sag and ag mill power calculation – Grinding Mill China Posted at: December 21, 2012 . ag mill power calculation… HOT STONE CRUSHING PLANT » 40TPH - 60TPH Crusher Plant

SAG Mill Optimization using Model Predictive Control …

MODEL PREDICTIVE CONTROL OF SAG WEIGHT. The MPC controller was installed to control the SAG mill weight, the belt weight in the ore feed system, and the SAG mill sound emissions. A diagram of the control strategy is shown in Figure 3. Figure 3 – SAG mill MPC control strategy The MPC SAG weight controller includes measured disturbance ...

Predicting SAG Ag Mill and HPGR Specific Energy

1, are used in AG/SAG mill modelling for predicting how rocks break inside the mill. From this description the model can predict what the throughput, power draw and product size distribution will be. Figure 4 – Drop-weight Tester The standard JK drop-weight test normally needs at least 75 kgs of raw material and hence

(PDF) Toward a Simple Approach Determining Single Stage SAG mill …

In this paper, the author presented a simple and sound approach to determining the preliminary SSSAG mill. aspect ratio. The approach is based on the concept of ball milling job to be done in a ...

Research on performance of a laboratory-scale SAG mill …

Here, the mill fraction of critical speed is the ratio of the actual speed of the mill to the critical speed, and the empirical formula [25] of the critical speed of the SAG mill is: (14) n 0 = 42.3 D where, D is the inner diameter of the drum and the unit is m, n 0 is the critical speed of the mill and the unit is rpm.

Mill Steel Charge Volume Calculation

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 from the top of the charge to the top of the mill. The % loading or ...

Dynamic modeling and simulation of a SAG mill for mill …

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 …

A comparison of SAG mill power models

• P is the power evolved at the mill shell, kW • PN is an empirical "power number" which varies with mill filling and speed, unitless • ρCharge is the density of the mill charge as given in Equation 3, t/m³ Ball charge is not explicitly used in the power formula, but is considered in the mill charge density formula: %(1 234 567ˆˆ ...

Modelling SAG milling power and specific energy

Tracking the mill performance showed that the mill power consumption decreased from 9.49 to 6.63 kWh/t (a nearly 30% reduction), P 80 of the mill product decreased from 611 to 355 μm, and the mill fresh feed flow rate increased from 511 to 521 t/h by decreasing the feed ore hardness from 112 min to 58 min based on SAG power …

Ball Mill Power Calculations

A nice and pretty online Ball Mill Power-draw Calculator was put live by one of the great prophets of grinding. comes ...

INFERENTIAL MEASUREMENT OF SAG MILL …

Powerdraw sensitivity. The sensitivities of the total, ball and rock charge fraction estimates to a 100 kW change in powerdraw are –4%, 2% and −6% volume, respectively. Taken in isolation, the magnitudes of the sensitivities appear near-credible. However, perhaps half of these figures is more realistic.

Circulating Load Calculation Formula

The pulp densities around your cyclone are sampled and known over an 8-hour shift, allowing to calculate corresponding to circulating load ratios and circulating load tonnage on tons/day or tons/hour. This is %Solids/Densities Based Circulating Load Calculation Method obtained from the pulp/slurry around your hydrocyclone. Cytec …

Energies | Free Full-Text | Operation Analysis of a SAG Mill …

In the formula, A represents the area ... Due to the large volume of the SAG mill, in order to facilitate the simulation and calculation, the SAG mill is simplified to a ring column model of ... As shown in Figure 9, the power of the best fracture case 6 is about 70 kW, and the power of the complete SAG mill is about 700 kW, which verifies the ...

A mill power equation for SAG mills | Mining, Metallurgy

Abstract. Development of an equation for tumbling charge and balls plus comparison to plant data suggests that the net mill power for cylindrical …

Calculation of energy required for grinding in a ball mill

The Bond work index, W i, as an indicator of the grindability of raw materials is not a material constant but rather it changes with change of size of the grinding product.Therefore, in practice we can expect some difficulties and errors when the energy consumption is determined according to this formula in the case when, for a given size …

Calculate a Mill's Operating Work Index

Calculate a Mill's Operating Work Index. Use this online formula to calculate a Ball Mill, Rod Mill or SAG Mill Operating Work Index. Based on Fred Bond's work you can estimate the energy used into your grinding circuit. This is the most accurate and informative method, but much of the data necessary for its application is not yet …

SAG Calculator

Formula for SAG Calculation: The sag of a power line or cable can be calculated using the catenary equation. The catenary is the curve that the power line assumes under the influence of gravity and tension forces. The general formula for sag calculation is as follows: S a g = h − h 2 − a 2

Sag in a Transmission Line: What is it? (And How To Calculate …

The formula to calculate sag changes based on whether the support levels (i.e. the transmission towers holding up the overhead conductor) are at the same level. Sag calculation for supports are at equal levels Suppose, AOB is the conductor. A and B are points of supports. Point O is the lowest point and the midpoint.

SAG mills selection methods. III. The F. Bond …

As you know, there are three calculation methods. The method selection depends on the crushing/grinding stage (the power size and the necessary finished class). The crushing work index ( CWi) is an …

An improved method for grinding mill filling

1. Introduction. Mill filling has a dominant effect on grinding mill performance (Apelt, Asprey and Thornhill, 2001), and therefore, its accurate measurement is vital for modelling grinding mill performance.Measuring filling is also necessary to estimate the composition of the load for mill modelling: rock and slurry for AG mills; rock, balls and …

A comparison of SAG mill power models

Gross power = no-load power + k × (Charge motion power) (4) The Morrell C-model provides a power draw relative to a motor input, and it must be converted to the same …

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. Models of this type do not predict the particle size ...

sbm/sbm power calculation formula of sag mill.md at …

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Bond Work Index Formula-Equation

You can read all the details of this now "Biblical" grinding power requirement calculation formula in Fred Bond's original paper. ... Ball Mill Grindability Test was conducted by standard practice using 100-mesh (150 pm) closing screens. The ball mill work index is shown below. BM Wi (kW-hr/st) = 17.97 ...

Grinding Mill Computer Model

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 …

CALCULATION OF THE REQUIRED SEMIAUTOGENOUS …

Estimation of drive power in WAM — CDBM circuit. With the known EWAM and ECDBM (kWh/t), the required drive power N (kW) is found from multiplication process in …

Choosing a SAG Mill To Achieve Design Performance

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 …

AN UPDATED DATA SET FOR SAG MILL POWER MODEL …

SAG mill power draw models are used in mill design and grinding circuit modelling to predict ... Austin proposed a geometric factor be applied to the formula for use in cone-ended mills. The author's ... This model is extremely sensitive to the angle α chosen by the operator of the calculation. This angle is not

A Method of C alculating Autogenous/ Semi …

SAG mills mimic the same shortcoming. It follows that in order to obtain the specifi c energy (SE) to achieve a certain transfer size, based on the 80 per cent passing value, an ineffi ciency factor must be applied to the SE of single stage ball mills, rod mills or AG/SAG mills when calculating power according to the Bond Third Theory method.

AN UPDATED DATA SET FOR SAG MILL POWER MODEL …

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 …

AG – Autogenous & SAG Semi-Autogenous Mill Design …

When the normal operating horsepower has been defined. It can be related to a design drive horsepower. If the mill operating horsepower is defined as "net at the shell", then the appropriate losses for trunnion bearings, pinionshaft bearings, and gearing must be accounted for to compute … See more

Formula For Recirculating Load Of Cyclones And Mill

sag mill load calculation Coal Crusher... LLC. circulating load being forecast. ... Power Calculation Formula Of Sag Mill 65 ... circulating load in roll mill ... how to caluclate recirculating lod of ball mill « mines ... WHY DO WE NEED SUCH A HIGH RECIRCULATING LOAD ON OUR BALL MILL? ... formula to calculate. ... . number of …

SAG Calculator | Edmund Optics

50mm and Larger Experimental Quality Double-Convex (DCX) Singlet Lenses