During the runningin process, the amount of steel balls is added for the first time, which accounts for 80% of the maximum ball load of the ball mill. Steel ball sizes are Φ120㎜, Φ100㎜, Φ80㎜, Φ60㎜, Φ40㎜. For example, the 100150 tons ball mill has a maximum ball loading capacity of tons. For the first time, 30% 40% of ...
WhatsApp: +86 18838072829We 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.
WhatsApp: +86 18838072829size 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 monosizes namely 8 mm + mm, 4 mm + mm and2 mm + mm for the experiment. A mill run having a mixture of the 3 ball diameter sizes was also conducted. It was
WhatsApp: +86 18838072829The grindingproduct size, P, in a Bond ball mill, ... These functions for G and P enable us to calculate the value of W i for any other size of grinding product if we know the work index W i and aperture size of the screen P k. Previous article in issue; Next article in issue; International Journal of Mineral Processing, 25 (1989) 4146 41 ...
WhatsApp: +86 18838072829Ball Mill Motor/Power Sizing Calculation Ballshaped Mill Design/Sizing Calculator To capacity required to grind a material from a giving feed size the a gives product size can be estimated by using that subsequent equal: find: W = power consumption declared to kWh/short to (HPhr/short ton = kWh/short ton)
WhatsApp: +86 18838072829Owing to the lack of effective energy consumption models of ball mills in the ceramic industry, a calculation model to forecast energy consumption of ceramic ball mills during the grinding process ...
WhatsApp: +86 18838072829Figure 3a and 3b gives the results of the computer calculation. The mill power at the pinionshaft for a 30% volume charge is the sum of: Figures 3a 3b give the power for an autogenous mill. Figures 4a and 4b are for the same size mill with a ball charge of 6% of mill volume (290 lbs. per cubic foot).
WhatsApp: +86 18838072829First you need the volumetric capacity of the mill, this is the volume of the mill at rest where the ore just reaches the discharge level (often about 1/3 of the internal volume). From this you need to subtract the volume of the grinding media. You now have the unit capacity. Then take the volumetric feed rate of the new ore per time.
WhatsApp: +86 18838072829C the mill drum rotational speed,% of the critical speed; D the mill internal diameter, m. At result B = 25mm or less necessary to use the correction factor, the grinding balls average diameter should be mm in the feed mixture. We draw your attention, a larger grinding balls need to use for future loads.
WhatsApp: +86 18838072829To put real numbers on this, that would be equavalent to a .012, .025, and .042″ stepover for a .125″ ball mill. Stepover =1/10 of diameter. Stepover =1/5 of diameter. Stepover =1/3 of diameter. As you can see, the change in quality is so dramatic that you might be tempted to always use the smallest stepover possible.
WhatsApp: +86 18838072829Calculating for Mill Diameter when the Critical Speed of Mill and the Diameter of Balls is Given. D = ( / Nc) 2 + d Where; D = Mill Diameter N c = Critical Speed of Mill d = Diameter of Balls Let's solve an example; Find the mill diameter when the critical speed of mill is 20 and the diameter of bills is 10. This implies that;
WhatsApp: +86 18838072829Small Ball Mill Capacity Sizing Table Ball Mill Design/Power Calculation
WhatsApp: +86 18838072829Popular answers (1) Lalit Thakur National Institute of Technology, Kurukshetra More balls with small size results in fine powder. As a thumb rule powder to be milled should be taken as 25% of total...
WhatsApp: +86 18838072829The balls in a ball mill need to flow in a figureof8 movement to maximize the energy converted to comminution/size reduction (most is converted to heat, light and sound. Indeed many ball mills ...
WhatsApp: +86 188380728291. Fill the container with small metal balls. Most people prefer to use steel balls, but lead balls and even marbles can be used for your grinding. Use balls with a diameter between ½" (13 mm) and ¾" (19 mm) inside the mill. The number of balls is going to be dependent on the exact size of your drum.
WhatsApp: +86 18838072829the mill is used primarily to lift the load (medium and charge). Additional power is required to keep the mill rotating. Power drawn by ball, semiautogenous and autogenous mills A simplified picture of the mill load is shown in Figure Ad this can be used to establish the essential features of a model for mill power.
WhatsApp: +86 18838072829Step Two: Calculate Your Compensated Speed. Given the new effective cutting diameter a "Compensated Speed" will need to be calculated. If you are using less than the cutter diameter, then its likely your RPM's will need to be adjusted upward (see Figure 3). KEY. ADOC = Axial Depth of Cut. D = Cutting Diameter. D eff = Effective Cutting ...
WhatsApp: +86 18838072829The majority of grinding balls are forged carbon or alloy steels. Generally, they are spherical, but other shapes have been used. The choice of the top (or recharge) ball size can be made using empirical equations developed by Bond (1958) or Azzaroni (1984) or by using special batchgrinding tests interpreted in the content of population balance models (Lo and Herbst 1986).
WhatsApp: +86 18838072829Steel balls are one of the most widely used grinding media in cement ball mills, their diameters can range from 20mm to 120mm according to different grinding requirements. In a cement ball mill, generally, φ50100mm steel balls are used in the coarse grinding chamber, φ2050mm steel balls are used in the fine grinding chamber. 2.
WhatsApp: +86 18838072829S=4*π*R 2, where: S the surface area of the ball; π PIconstant, a mathematical constant that is equal to the ratio of the circle's circumference to its diameter. isa commonly used value for PI; R the radius of the ball. The volume of a grinding ball is determined by the formula: V=4/3*π*R 3, where: V the volume of the ball.
WhatsApp: +86 18838072829One can argue the f50 is a more realistic value since balls wear and the average ball size might be closer to half the maximum. Then the multiple would be closer to 13 times the maximum particle size fed to the ball mill. A f80 = 6 mm would need a ball size of 75 mm. An empirical model from "Emerging Trends in Mineral Processing", 2005, is ...
WhatsApp: +86 18838072829Once you measure the ball charge and measure the total charges then you need to target an appropriate ball to rock ratio for a chosen mill throughput rate. With high aspect ratio SAG mills total charge to ball charge ratio should be greater than 2 (up to ) for a coarse mill feed (say F80 > 110 mm).
WhatsApp: +86 18838072829