Austin's model, as has been mentioned, was not developed for ball mills but for SAG mills. Its over prediction of the power draw of 19% and high standard deviation (%) are perhaps ...
WhatsApp: +86 18838072829(JKDWT) "A×b" and the Bond ball mill work index. The SAG and ball mills power draw is calculated using semiempirical equations, as a function of mill geometry, speed and load.
WhatsApp: +86 18838072829From this concept came two equations: (a) the equation to determine the Work Index from Bond grindability tests, and (b) the Bond equation, which uses the Work Index to determine the energy needed for grinding. Grinding Media
WhatsApp: +86 188380728293. Power draw of the comminution equipment (kW) •In the case of mills, the power draw should be represented in terms of power at pinion for gear and pinion drives and at shell for gearless drives. For crushers, this should be the net power draw, that is, the gross (motor input) power draw less the noload power. 4.
WhatsApp: +86 18838072829There is no doubt about the importance of Fred Bond's methodology [1,2,3,4,5] and its practical value in the field of comminution, not only in tumbling mills design and operation but also in the characterization of mineral raw materials grindability. The Third Law of Comminution, also known as the Bond's Law, is summarized in Equation (1) .
WhatsApp: +86 18838072829implicitly modelled the impact of makeup balls diameter and discharge level on grate discharge mills' power. Bond published Equation 2 for overflow discharge ball mills. Furthermore, to calculate grate discharge mills' power, he proposed the multiplying factor of KWb = ( p)Cs( 2(910Cs))(
WhatsApp: +86 18838072829You need a twostage solution, first stage opencircuit mill and then second stage closedcircuit mill. First stage, will be broken into two parts as well, you use a Bond rod mill work index for the coarse component of the ore (+ mm) and the Bond ball mill work index for the fine component ( mm).
WhatsApp: +86 18838072829For a ball mill circuit, the functional performance equation is as follows. References Production Rate of New Product = Total Mill Power 1. Bond,, 1952, "The Third Theory of Draw x Classification System Efficiency x Material Comminution", Trans. AIME,, pp. 484495.
WhatsApp: +86 18838072829tion related to the operation of the circuit (F80, P80, power and mill feed rate). THE BOND EFFICIENCY OF A GRINDING CIRCUIT In the plant: 1. Define the circuit for which the Bond Efficiency is to be determined. 2. Procure samples of the circuit feed and product. 3. Obtain the power draw of the size reduction equipment
WhatsApp: +86 18838072829Abstract The Bond ball mill grindability test is run in a laboratory until a circulating load of 250% is developed. It provides the Bond Ball Mill Work Index which expresses the resistance of material to ball milling.
WhatsApp: +86 18838072829Mike Daniel (2006) reports the measured input power to a laboratory ball mill apparatus is J/rev ( mWh/rev) versus 60 J/rev ( mWh/rev) in some of Fred Bond's discussions...
WhatsApp: +86 18838072829Six tests were carefully performed with both mills using the same aggregate rock sample and with the same method of grindability testing based on Fred Bond's Ball Mill Grindability Work Index (BWi ...
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WhatsApp: +86 18838072829Austin et al. concluded that a single expression for capacity is not adequate for all mills. Equations for mill sizes less than in diameter and greater than were proposed: ... For wet ball mills, Bond expressed power draw as a function of the total mass of media:Pâ†"M / Mâ†"B Φâ†"V (1 ...
WhatsApp: +86 18838072829fred bond ball mill power draw equations T09:01:16+00:00 AMIT 135: Lesson 7 Ball Mills Circuits Mining Mill . Equations for mill sizes less than 381meters in diameter and greater than 381meters were proposed: t/h D 381 m Wet Ball Mill Power Draw (Bond) For wet ball mills, Bond expressed power draw as a function of the total mass ...
WhatsApp: +86 18838072829The test enables basic grinding power requirement in ball mills to be determined, from the feed 80% passing size (F80) to circuit 80% passing size (P80), using the classic Bond formula. The rod mill work index test requires 20 kg of material, which is crushed to mm (1/2) and tested in a standard Bond Rod mill.
WhatsApp: +86 18838072829Rowling are used to calculate the mill power draw. The Morgärdshammar equation and the IMM equations are shown for comparison. The method of use is similar to the AM section Ball Mill Design The ball mill designs also follow the Bond/Rowlings method with comparison with other methods. Again the method of use is the same
WhatsApp: +86 18838072829The grindingproduct size, P, in a Bond ball mill, which is given by the aperture size which passes 80% of the grinding product as a function of the aperture size of the test screen Pk, Can be expressed by the formula P=Pk/K2. These functions for G and P enable us to calculate the value of Wi for any other size of grinding product if we know ...
WhatsApp: +86 18838072829in a Bond ball mill for, 1, 2, 4, and 8 min. After each grinding cycle, the grinding product PSD is determined and returned to the mill for the subsequent grinding cycle.
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WhatsApp: +86 18838072829Bond ball Wi kWh/tonne 26 6 JK A*b sg 182 20 AG/SAG mill circuits ... Figure 3 Accuracy of Prediction of AG/SAG Mill and Ball Mill Power Draw (equation 3)
WhatsApp: +86 18838072829The Bond Equation as found in reference 5 is: W = 10Wi/ 10Wi/ Where: W = kwh per short ton. Wi = Work Index determined from crushing and grinding tests. P = The size in microns (micrometers) that 80% of the product is finer than. F = The size in microns (micrometers) that 80% of the feed is finer than.
WhatsApp: +86 18838072829BM Wi (kWhr/st) = BM Wi (kWhr/mt) = Bond Ball Mill
WhatsApp: +86 18838072829E = K (P80 ⁿ F80 ⁿ ) where K and n are empirical constants measured for your ore. One solution for this equation Bond's equation if K = (10·Wi) and n = ½. 1. Reference ore. Run a ...
WhatsApp: +86 18838072829The work index equation for a ball mill test was generated by Fred Bond to empirically predict the operating work index of an industrial ball mill (8 ft dia by 8 ft effective grinding length ...
WhatsApp: +86 18838072829A series of comminution tests was carried out to evaluate three multipass HPGR circuits and a jaw crusherball mill circuit. Combinations of HPGR units ( m and m diameter), jaw crushers and Bond ball mills were used to grind a 32 mm top size porphyry copper feed (BBWI = ) to a product P80 size of about 150 µm.
WhatsApp: +86 18838072829the form of Equation (3). The Jar Mill test favoured by gives a table of results of E and measured size x for a progressive batch grinding test; these results can be fitted as demonstrated in Figure 4. A series of Bond ball mill work index tests run at different closing mesh sizes can be fitted in almost the same way.
WhatsApp: +86 18838072829energy in ball mills for which the Bond equation was originally designed. The standard Bond grindability test . ... revolutions per minute which equates to a mill power draw of W.
WhatsApp: +86 18838072829Consultant at The Bond rod mill work index is a commonly used metric to describe ore grindability in the middle size classes, generally from 12 mm down to 1 mm. There are a couple ...
WhatsApp: +86 18838072829factors with the threestage Bond equation gives this overall equation for grinding specific energy consumption. from a primary crusher product size, F80, to a ball mill cyclone overflow product size, P80. E=10Wi C. ( 1. 1. 10000 F 80 ) [. + 10Wi RM ( 21100 101000 )+10Wi ( P1 BM.
WhatsApp: +86 18838072829Ball Mill Motor Power Draw Sizing and Design Formula. The following equation is used to determine the power that wet grinding overflow ball mills should draw. For mills larger than meters (10 feet) diameter inside liners, the top size of the balls used affects the power drawn by the mill. This is called the ball size factor S. The following ...
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