Ball Mill Determine Top Ball Charge

Charge behaviour and power consumption in ball mills

Aug 01, 2001 Fig. 1 shows typical charge shapes predicted for our ‘standard’ 5 m ball mill and charge (described above) filled to 40% (by volume) for four rotation rates that span the typical range of operational speeds. For such a charge with a realistic size range, the free surface of the charge is well defined at low and intermediate rotation rates. For N=60%, material moves with the mill rotation

Ball Mill Loading - Wet Milling - Paul O. Abbe

The starting point for ball mill media and liquid charging is generally as follows: 50% media charge. Assuming 26% void space between spherical balls (non-spherical, irregularly shaped and mixed-size media will increase or decrease the free space) 50% x 26% = 13% free space. Add to this another 45% to 50% above the ball charge for total of 58%

TECHNICAL NOTES 8 GRINDING R. P. King

The geometry of a mill with conical ends is shown in Figure 8.6. The total volume inside the mill is given by Vm 4 D2 mL 1 2(Lc L) L 1 (Dt/Dm) 3 1 Dt/Dm (8.16) The density of the charge must account for all of the material in the mill including the media which may be steel balls in a ball mill

DESIGN AND ANALYSIS OF BALL MILL INLET CHUTE

Ball mills (Fig 1.1) are coming in cement plant areas of raw grinding, coal grinding and cement grinding which in turn as ... larger centre radius than the centre height of the ball charge with the mill stopped. Of course, due to the large openings ... top of the mill inside diameter to the surface of the charge is

Bond formula for the grinding balls size calculation

Oct 19, 2017 There is a mathematical solution to this problem – the Bond formula. It uses to help determine the grinding media optimal size must be loaded into the ball mill for proper operation ensure. The calculation formula is below: B – the grinding balls diameter, mm; A – the correction factor (for grinding balls A = 20,17; for cilpence A = 18,15);

Ball Mill - an overview | ScienceDirect Topics

8.3.2.2 Ball mills. The ball mill is a tumbling mill that uses steel balls as the grinding media. The length of the cylindrical shell is usually 1–1.5 times the shell diameter (Figure 8.11 ). The feed can be dry, with less than 3% moisture to minimize ball coating, or slurry containing 20–40% water by weight

DYNAMIC ANALYSIS FOR BALL MILL FOUNDATION

In mining industry, ball mills normally operate with an approximate ball charge of 30% with a rotational speed close to 11 rpm. The mill is fed at one end of the cylinder and the discharge

BALL MILL Objective: To Determine The (a) Critical

2. Note down the initial meter reading. 1. Now charge the mill with feed. 2. Operate the mill for 20 minutes. and note down the final meter reading. 3. Take out the material from the mill and do the sieve analysis of the product. Data: 1. Radius of ball mill R = 16.48 cm 2. Radius of ball r = 1.26 cm 1. Density of feed p = 2000 kg/m3 2

PERFORMING A CEMENT PLANT OPERATIONS AUDIT

Internal inspection of ball charge, liners and screens; Measurement of screen slots; Axial samples of material through the entire mill length. Residues and Blaine determinations to be done by plant laboratory, required sieves from 2mm to 45 ; Ball samples at same locations to determine charge

THE OPTIMAL BALL DIAMETER IN A MILL

Investigations were carried out in a laboratory ball mill having the size of DxL = 160x200 mm with a ribbed inside surface of the drum. The mill ball loading was 40% by volume, the rotation rate was equal to 85% of the critical speed. Balls were made from steel: S4146, extra high quality, having hardness 62 2 HRC according to Rockwell

calculates the grinding charge of a ball mill | Mining

Mar 08, 2013 To calculate grinding media charge for continuous type ball mill, M = 0.000676 x D2 x L Example

The Effect of Ball Size Diameter on Milling Performance

An investigation was conducted to determine the effect of the ball diameter sizes on milling operation. A laboratory size ball mill was used with ball media of sizes 10 mm, 20 mm and 30 mm respectively. Quartz was the material used to perform the experiment and was arranged into 3 mono-sizes namely -8 mm +5.6 mm, -4 mm +2.8 mm and-2

AMIT 135: Lesson 6 Grinding Circuit – Mining Mill

The mill product can either be finished size ready for processing, or an intermediate size ready for final grinding in a rod mill, ball mill or pebble mill. AG/SAG mills can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill, and some or all of the work of a ball mill

Ball charges calculators

Contact. - Ball charges: This calculator gives the surface and the average weight of the ball charges. It gives also a rough interpretation of the ball charge efficiency: - Ball top size (bond formula): calculation of the top size grinding media (balls or cylpebs): -Modification of the Ball Charge: This calculator analyses the granulometry of the material inside the mill and proposes a modification of the ball charge in order to improve the mill

A Method to Determine the Ball Filling, in Miduk Copper

Mill Ball (%) = 100{[(ball volume in the 0.4 m3 sample)* 58.52] / 0.4}/297.96 (3) According to the results (Table 1), the ball filling percentage was obtained 1.3%. However, these results may have some field errors. Acquired Results from Abrasion Test Ball abrasion was calculated in 4 conditions which are as follows: Ball charge program

Ball mill media optimization - Metcom Tech

ball charge is close to 95 kg (209 lb), occupying 34 percent of the mill volume. Balls are used that represent a fully graded charge based on constant wear rate in a continuously operating mill. Slurry volume occupies the 40 percent voids volume in the 34 percent ball charge. The drive shaft is torque-metered and records once per second

Ball Mill Design/Power Calculation

Jun 19, 2015 W = weight of charge C = distance of centre of gravity or charge from centre of mill in feet a = dynamic angle of repose of the charge N = mill speed in RPM. HP = A x B x C x L. Where. A = factor for diameter inside shell lining B = factor which includes effect of % loading and mill type C = factor for speed of mill

Calculate and Select Ball Mill Ball Size for Optimum Grinding

Aug 02, 2013 Based on his work, this formula can be derived for ball diameter sizing and selection: Dm = 6 (log dk) * d^0.5 where Dm = the diameter of the single-sized balls in mm.d = the diameter of the largest chunks of ore in the mill feed in mm

CALCULATION OF THE POWER DRAW OF DRY

To determine the power that a dry grinding needs, full grate discharge mill Equation 1 is multiplied by the factor of 1.08. A multi-compartment ball mill consists of two or more grate discharge ball mills in series. The same equation is used to calculate the power that each ball mill compartment should draw. The total power is the sum of the power calculated for each of the separate compartments

MODULE #5: FUNCTIONAL PERFOMANCE OF BALL

If a ball mill contained only coarse particles, then 100% of the mill grinding volume and power draw would be applied to the grinding of coarse particles. In reality, the mill always contains fines: these fines are present in the ball mill feed and are produced as the particles pass through the mill