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This will impact the equipment chosen for your project.CORRELATION BETWEEN BOND WORK INDEX AND, The Bond's standard ball mill is used to determine the work index value of differ ent samples. The Bond work index is defined as the kilowatt-hours per short ton required to break from infinite size to a product size of 80% passing 100 µm.
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Application of Operating Work Indices in Autogenous, Ball Mill Wio, BWio 86 Circuit Wio, OWio 146 Bond Ball Mill Work Index, BWi, kWh/t 134 Bond Rod Mill Work Index, RWi, kWh/t 181 Table 1 Example of AG/SAG Ball Mill Circuit Wio Calculations [1] [2] ABstrAct Optimum use of power in grinding, both in terms of grinding efficiency and use of installed capital, can have a …
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Table B.13. Cumulative size distribution: 1 minute, 25% -19+12.7 mm, 70% CS, Rail lifter. - "Measuring the efficiency of the tumbling mill as a function …
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Commentary on the apparatus of the Bond rod mill work index The Bond "Third Theory" of comminution was originally divided into three size classes reflecting the varieties of comminution equipment common during the time period when Bond (and his collaborators) were gathering the information to calibrate comminution models.
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Basic calculation formulas for cement ball mill calculate and select ball mill ball size for optimum grinding in grinding selecting calculate the correct or optimum ball size that allows for the best and optimumideal or target grind size to be achieved by your ball mill is an important thing for a mineral processing engineer aka metallurgist to do.Formula 39 S To Calculate …
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Where, WioACTis the Actual Operating Bond Work Index (kWh/t), W is the specific energy input (kWh/t), P80 is the 80% passing size of product (µm), and F80 is the 80% passing size of circuit feed (µm). 2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal
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A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes.There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand or by animals (e.g., via a hand crank), working animal (e.g., horse mill), wind or water ().
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The polytropic efficiency according to the CDRA is the curve parameter n o. The message of this figure is that the ideal gas formula underestimates the polytropic efficiency for dry air in the order of up to 1.5%-points. This applies especially for highly efficient axial compressors with a polytropic efficiency of up to 93%.
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To measure grindability, Bond developed 'Bond's Work Index' (BWI), a 'test mill' and a testing procedure for WI. With the help of this we can work out power required to grind a material from a given feed size to a product of given fineness. Water Spray in Cement Mills.
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Bond Standard Circuit Work Index: Assume the rod mill Work Index of 9.5 applies from the actual rod mill feed sizeof 19,300 mµ (although some of this work might ideally be done by crushers to achieve a rod mill F80 of 16,000 m) to a rod µ mill (circuit) product size of 1,000 µm. W Total = 2.32 + 4.77 = 7.09 very large size (FkWh/t of . 9.70 ...
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Ball Mill Design/Power Calculation. The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond Work Index, bulk density, specific density, desired mill tonnage capacity DTPH, operating % solids or . More
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Bond Grinding Circuit Efficiency Meeting of Bond Efficiency Guideline Working Group of the Global Mining and Standards Group Salt lake City, 2014 Based on Presentation to the 2008 Meeting of SME, by C.A. Rowland, Jr. and R.E. McIvor. Bond Grinding Circuit Efficiency • The Bond Work Index equation • Ore test WI • Circuit operating WI
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The Work Index is a fitted coefficient to Bond's equation given in the picture above. The work index can either be measured in the laboratory (the Bond ball mill work index determination is a...
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Typical Mill Circuit Represented by the Bond Ball Mill Test. The procedure for the work index test bases the BW i value on the calculation of new fines generated in the test. This means that the fraction of fines in the feed should not influence the test result significantly, if at all.
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The Bond work index (BWI) is a well-known method used when selecting comminution equipment, to evaluate the grinding efficiency and to calculate the required grinding power. Although considered an industry standard, Bond did not fully define that procedure, and therefore significant discrepancies in test results can sometimes be obtained …
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To measure grindability, Bond developed 'Bond's Work Index' (BWI), a 'test mill' and a testing procedure for WI. With the help of this we can work out power required to grind a material from a given feed size to a product of given fineness. Other index known as 'Hardgrove Index" is also used to scale grindability of materials, particularly coal.
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The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined media and ore charge. The Work Index calculated from the testing can be used in the design and analysis of ball mill circuits. The test requires a minimum of 10kg of sample that has been stage-crushed to passing size of <3.35 mm.
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Figure 5-13 Bond Work Index of SAG Mill Feed..... 66 Figure 5-14 Power of Different Type of Liners at Different Speeds and 6 month Service Life .. 68 Figure 5-15 Power of Different Type of Liners at Different Speeds and 12 months Service Life68
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What is the efficiency of a milling process? Different possibilities to define energy efficiency: 1. Specific energy of mill compared to new created surface energy → not meaningful, efficiency much smaller that 1% 2. Specific energy of mill compared to minimum specific energy requirement in so-called element tests. However, here at least two
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Bond Ball Mill Work Index, BWi, kWh/t 13.4 Bond Rod Mill Work Index, RWi, kWh/t 18.1 Table 1. Example of AG/SAG Ball Mill Circuit Wio Calculations [1] [2] ABstrAct Optimum use of power in grinding, both in terms of grinding efficiency and use of installed capital, can have a large effect on profitability.
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Since the "job" of most ETFs is to track an index, we can assess an ETF's efficiency by weighing the fee rate the fund charges against how well it "tracks"—or replicates the ...
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grinding cycles. The Bond Work Index is calculated using the formula: 𝑖=1,1 44,5 𝑃𝑐 0,23𝐺,82(10 √𝑃80 −10 √𝐹80) (1) where W i – Bond work index (kWh/t) P c – test sieve mesh size (µm) G – weight of the test sieve fresh undersize per mill revolution (g/rev) F 80 – sieve mesh size passing 80% of the feed before ...
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How to Size a Ball Mill Design Calculator Formula. 15/05/2015 In this equation, E is the specific energy required for the grind, and F80 and P80 are the sizes in micrometers that 80% of the weight passes of the mill feed and product respectively The parameter Wi, known as the work index of the ore, is obtained from batch bench tests first devised by Bond (1961) The power …
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The work index Wi was defined by F. Bond as the specific energy (kWh/ton) required to reduce a particulate material from infinite grain size to 100 microns. The calculation is …
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The turbine efficiency factor E accounts for the mechanical efficiency of the turbine only. It does not include the isentropic efficiency. Note : There is an anomaly in the steam calculation for region 3 between the saturated vapour line, the region 2/3 boundary, and the critical pressure.
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Bond Rod Mill Work Index. The average results for the Bond Rod Mill Work Index, which measures the resistance of the ore to grinding to a coarse product size, are 13.2 kilowatts per tonne for ...
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12%Using the Bond work index to measure operating comminution efficiency C. A. Rowland 1 Mining, Metallurgy & Exploration volume 15, …
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The Bond Work Index is a factor that measures the energy consumed in size reduction operation of the ore. The Bond's Work Index equation is: W=WI* (10/√P80 -10/√F80) where W= the energy input (Work input) per ton, kwh/metric ton WI= Work Index= specific energy per ton, kwh/metric ton (characterizes the ore)
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The Bond equation is used to calculate ball mill specific energy from T 80to the final product P 80size. The total circuit specific energy is the sum of the SAG mill and ball mill specific energies. W SAG= R (Ms+16000)/(Ms.447.3) (4) W T= K a . K b . W SAG . [10. BWi. (T 80 -0.5-1700-0.5). EF5] + W BM . K BM(5) Where: W
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Bond Standard Circuit Work Index: Assume the rod mill Work Index of 9.5 applies from the actual rod mill feed sizeof 19,300 mµ (although some of this work might ideally be done by crushers to achieve a rod mill F80 of 16,000 m) to a rod µ mill (circuit) product size of 1,000 µm. W Total = 2.32 + 4.77 = 7.09 very large size (FkWh/t of . 9.70 ...
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