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Ball Mill Motor/Power Sizing Calculation. A) Total Apparent Volumetric Charge Filling – including balls and excess slurry on top of the ball charge, plus the interstitial voids in between the balls – expressed as a percentage of the net internal mill volume (inside liners). B) Overflow Discharge Mills operating at low ball fillings ...
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 y=x Fig. 2. …
Ball Mill Design/Sizing Calculator. The power required to grind a material from a given feed size to a given product size can be estimated by using the following …
Then in ball-wear formula (25), T = 6.9/K Log10 Da/Db; but from (29), K = Rt/Wt. Then T = 6.9Wt/Rt Log10 Da/Db T is 1 day, Wt is the original weight of the ball charge, and Rt is the ball wear for one day. Then Log10 Da/Db = Rt/6.9Wt are all known, and it is only necessary to solve for Db, the diameter of the balls to be added.
Multi-compartment ball mills are relatively inefficient at size reduction and have high specific energy consumption (kWh/t). Typical specific energy consumption is 30 kWh/t in grinding of cement. ...
Other common units of power include kilowatts (kW), British thermal units (BTU), horsepower (hp), and tons. Watts, kilowatts and kilowatt-hours: Watts (W) is a unit of power used to quantify the rate of energy transfer. It is defined as 1 joule per second. A kilowatt is a multiple of a watt. One kilowatt (kW) is equal to 1,000 watts.
Key benefits. High reliability – over a century of experience with 4000+ ball mills installed globally. Large through-flow area ensures low pressure drop across the mill. Horizontal slide shoe bearing design allows much simpler foundations and reduced installation height. Increased effective grinding area with Stanex diaphragm design.
Procedure to verify the laws of size reduction using Ball mill. Note the initial dial reading of energy meter as N1. Take the clean metal chamber (of ball mill) with sufficient number of balls. Operate the ball mill without load for 30min. Note the reading (revolutions) in energy meter is as, N2.
If P is less than 80% passing 70 microns, power consumption will be. Ball Mill Power Calculation Example. A wet grinding ball mill in closed circuit is to be fed 100 TPH of a material with a work ...
10. Mill Power Consumption 11. Brake KW 12. Mill Main Motor Rating (KW) 13. Total weight Excluding motor 14. Overall dimensions 15. Solid Concentration (w/w %) in mill 16. Method of Classification 17. Initial Ball Charge – quantity and distribution 18. Ball Consumption (kg per ton of limestone) 19. Refilling Ball size diameter
Differentiation of KW with respect to V in equation (2) shows that power draw increases with charge level to peak at about Vp = .58. For rod, ball, or pebble mills the peak is usually near Vp = .50, while actual observations as low as V= .42 have bean made in some ball mills (Rowland, 1973). See Figure 2.
The power required to crush 125 tons/hr of cement raw material with a feed size of 5.08 cm is 0.430 kw. Calculate the size of the product using Rittingers law. The Rittingers law constant is 1.357 kJ-cm/ton. ( Answer ... A ball mill of 1.2 m diameter is being run at N = 50 rpm. What is the size of the balls that we have to employ for proper ...
A ball mill operating in closed circuit with a 100-mesh screen gives the screen analyses below. The ratio of the oversize to the undersize (product) stream is 1.0705 when 200 tons of galena are handled per day. The ball mill requires 15.0 hp when running empty (with the balls but without galena) and 20.0 hp when delivering 200 tons per day …
A ball mill, operated in a closed circuit with a classifier, is used to grind calcite. The ball mill feed (25 tons/hr) is estimated to have a specific surface of 292 sq cm/gram. When the ball mill is operated with a recycle of 75 tons/hr, 75 kW are required to drive the ball mill. Determine the efficiency of the ball mill. Tyler Screen Mesh
Ball Mill Motor/Power Sizing Calculation. A) Total Apparent Volumetric Charge Filling – including balls and excess slurry …
Example calculation of test mill grinding rates Whether from a plant survey or torque-mill test, the calculation method of the mill energy specific cumulative grinding rates is shown by the following example. Using plant data, the value of E is the specific energy input to the solid material as it passes through the
The load of balls in a ball or tube mill is normally such that when the mill is stopped, the balls occupy about one-half the volume of the mill. The void fraction in the mass of balls, when at rest, is typically …
Ball-mill power, 108 kw. In the first stage, 9.11 T. of minus 200-mesh material were produced per hour and 11.98 kw.-hr. were required for each ton of minus 200-mesh material produced. The classifier delivered 32 T. of sand per hour. ... In order to calculate the maximum value of the blow struck, the author uses the second order …
Objectives. At the end of this lesson students should be able to: Explain the grinding process. Distinguish between crushing and grinding. Compare and contrast different type of equipment and their components used for grinding. Identify key variables for process control. Design features of grinding equipment (SAG, BALL and ROD MILLS)
Since the feed rate of second stage mills in the Aoshan concentrator was 400 t/h, the total grinding unit consumption of second and third stage ball mills was 13 kWh/t. (3) P = η P 0 where P is the active power of the ball mill (kW); η is the power factor (80% in this paper); P 0 is the installed power of the ball mill (kW).
Calculation of Surface.—The surface area of the material finer than 60 microns in the product is measured by the turbidimeter. The surface of the portion coarser than 60 microns may be computed from a sieve analysis. ... In very fine grinding in tube mills, the balls near the discharge end become coated with reconsolidated fine material, …
closing screen for the ball mill test one (standard square root of 2 series) mesh size coarser than the plant ball mill circuit P80. If between standard mesh sizes, the finer of the chose two. Results of Bond ball mill tests conducted with closing screens of 75 µm or finer are to be treated with caution. The
Ball mill liner efficiency based on liner geometry and its influence on kW-hours/ton, total tons/life cycle, and P80 transfer to cyclones. Ball mill grind is based on different principle; it has some attributes similar to SAG mill optimization.
DOVE small Ball Mills designed for laboratories ball milling process are supplied in 4 models, capacity range of (200g/h-1000 g/h). For small to large scale operations, DOVE Ball Mills are supplied in 17 models, capacity range of (0.3 TPH – 80 TPH). With over 50 years experience in Grinding Mill Machine fabrication, DOVE Ball Mills as ...
Question 3 [25 marks) A ball mill is operating at an efficiency of 80% with a filling volume of maximum 1.32 m. The ore has a W. of 19 kW/on. The RD of the crushing balls are 5.0. The charge volume is about 45%. Calculate the following a) What length and diameter of mill is required to reduce ore sizes from 4 mm to 200 um?
Motor output power KW = Motor input power x Rated motor efficiency Motor output power KW = 0.001 x (1.73 x amperage x voltage x power factor) x Rated motor efficiency/ Our power factor is 0.99 electricians tell me. My ball load measured using exposed liner count comes in at around 32% and my power-draw at 1084 kW.
