Sep 22, 2017 Commentary on the apparatus of the Bond rod mill Work Index. by Alex Doll December, 2015 alex.doll@sagmilling. The Bond “Third Theory” of comminution was originally divided into three size classes reflecting the varieties of comminution
Read MoreJan 01, 2013 To calculate Bond rod-mill work indices, the four samples were screened and the particle size distributions plotted in Fig. 2.The plot was used to find F 80 of the samples for calculations. Fig. 3, Fig. 4 show the grinding kinetics of Pb, Cu, Fe, and Mn ores in the Bond rod-mill in different test-sieves. The slopes of all lines in the figures are equal to the k value of Eq.
Read MoreThe Bond rod mill work index is not as common as the Bond ball mill work index, and there are two different variations on the mill apparatus.The SAGMILLING.COM models expect a mill with a "wave liner", and is not compatible with mills using "smooth liners".
Read MoreAn global operational work index, Wiog, is defined for a conventional grinding plant consisting of a rod mill followed by three inverse hydrocyclone-ball mill grinding circuits and its value is ...
Read MoreJan 01, 2013 To calculate Bond rod-mill work indices, the four samples were screened and the particle size distributions plotted in Fig. 2.The plot was used to find F 80 of the samples for calculations. Fig. 3, Fig. 4 show the grinding kinetics of Pb, Cu, Fe, and Mn ores in the Bond rod-mill in different test-sieves. The slopes of all lines in the figures are equal to the k value of Eq.
Read MoreRod mill power is dependent on mill capacity and work index. Mill power increases with: Increasing rod charge; Increasing mill speed; Increasing mill length. Rowland and Kjos (1980) provided an expression to quantify power draw at the pinion shaft per unit mass of rods
Read MoreThe Bond rod mill work index is not as common as the Bond ball mill work index, and there are two different variations on the mill apparatus.The SAGMILLING.COM models expect a mill with a "wave liner", and is not compatible with mills using "smooth liners".
Read MoreIn Mineral Processing Design and Operations (Second Edition), 2016. 8.3.1 Rod Mill Charge. Rod mill charges usually occupy about 45% of the internal volume of the mill. A closely packed charge of single sized rods will have a porosity of 9.3%. With a mixed charge of small and large diameter rods, the porosity of a static load could be reduced even further.
Read MoreAn global operational work index, Wiog, is defined for a conventional grinding plant consisting of a rod mill followed by three inverse hydrocyclone-ball mill grinding circuits and its value is ...
Read MoreThe rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing 12.7 mm (½ inch, the original test being developed in imperial units) to a product size of approximately 1 mm (in the original and still the standard, 14 mesh; see Chapter 4 for definition of mesh), thus determining the rod mill work index ...
Read MoreJan 01, 1988 The basic objective is to achieve a 100% circulating load in a locked-cycle test using a calibrated laboratory rod mill. The work index is then inferred from the feed and product size (FS0, PS0), the classification size, P, and the mass of material finer than P (M) produced per revolution of the mill (R), the Grp: WI I 62 p0.23 .
Read MoreJul 30, 2020 Measuring ore grindability in rod mills. The Bond Rod Mill Work Index is a measure of the resistance of the material to grinding in a rod mill. It can be used to determine the grinding power required for a given throughput of material under rod mill grinding conditions. It is a 'locked cycle' test conducted in closed circuit with a laboratory ...
Read MoreW is the work index measured in a laboratory ball mill (kilowatt-hours per metric or short ton) P 80 is the mill circuit product size in micrometers; F 80 is the mill circuit feed size in micrometers. Rod mill. A rotating drum causes friction and attrition between steel rods
Read MoreRod mills normally carry 35 to 65% rod charge by volume. The limits on charge level are (1) keeping the feed end trunnion open so that feed will get into the mill, and (2) keeping the rod charge low so rods will not work their way into discharge openings where they can cause rod
Read MoreThe model was validated for four materials, showing that it can predict the Bond rod mill work index with deviations below 10%. Requiring only 1.5–3kg of sample, the procedure is demonstrated to ...
Read MoreNo 1 rod mill/ball mill circuit was operating very effi ciently when comparing the combined operating work indices for both mills with the rod mill and ball mill laboratory work indices. Note, in Figure. 1, that the rod mill product slope is less than 0.5 due to an extra amount of
Read MoreEF5BM=[ P80+10.3 1.145×P80] ( 3 ) The EF4 formula requires both the rod mill and ball mill work index (rod mill Wi is used to calculate the optimal feed size) and because this is a “single-stage ball mill” calculation, the F80 is actually the rod mill feed size (10,000 µm) from Table 1 and the P80 is the ball mill circuit product. The EF5 factor only applies below 75 µm to ball
Read MoreWe have evaluated more than 750 ore samples from more than 300 deposits using the MacPherson 18” mill test. The MacPerson Autogenous Grindability Test determines the MacPherson Correlated Autogenous Work Index*. This can be used in conjunction with the Bond Rod and Ball Mill Work
Read MoreThe Bond rod mill work index is not as common as the Bond ball mill work index, and there are two different variations on the mill apparatus.The SAGMILLING.COM models expect a mill with a "wave liner", and is not compatible with mills using "smooth liners".
Read MoreThe rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing 12.7 mm (½ inch, the original test being developed in imperial units) to a product size of approximately 1 mm (in the original and still the standard, 14 mesh; see Chapter 4 for definition of mesh), thus determining the rod mill work index ...
Read MoreThe grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill. The Rod Mill Work Index (RWI) is used for particle size determination in a size range from 25 mm down to 2.1 mm whereas Ball Mill Work ...
Read MoreBond Rod Mill Grindability Test. The test determines the Bond Rod Mill Work Index which is used with Bond’s Third Theory of Comminution to calculate net power requirements when sizing ball mills*. Various correction factors may have to be applied. The test is a closed-circuit dry grindability test performed in a standard rod mill.
Read MoreEF5BM=[ P80+10.3 1.145×P80] ( 3 ) The EF4 formula requires both the rod mill and ball mill work index (rod mill Wi is used to calculate the optimal feed size) and because this is a “single-stage ball mill” calculation, the F80 is actually the rod mill feed size (10,000 µm) from Table 1 and the P80 is the ball mill circuit product. The EF5 factor only applies below 75 µm to ball
Read MoreIndex (BWi), the Rod Mill Work Index (RWi), the Crusher Work Index (CWi) and the Abrasion Index (Ai). Over the years, it has been determined that Efficiency Factors (EF1 to EF9) should be applied to Equation 1 to drive the corrected power requirement (Rowland, 1982).
Read MoreBond Work Index for Rod Mill. Product Image. Introduction. The Bond Work Index for Ball Mill is a special equipment for testing Bond ball mill work index. Simple lab test can choose ball mill by power method or judge the effects of material properties change to the ball milling process or the operation condition of crusher by using this ...
Read MoreThe model was validated for four materials, showing that it can predict the Bond rod mill work index with deviations below 10%. Requiring only 1.5–3kg of sample, the procedure is demonstrated to ...
Read MoreNo 1 rod mill/ball mill circuit was operating very effi ciently when comparing the combined operating work indices for both mills with the rod mill and ball mill laboratory work indices. Note, in Figure. 1, that the rod mill product slope is less than 0.5 due to an extra amount of
Read MoreRod mills normally carry 35 to 65% rod charge by volume. The limits on charge level are (1) keeping the feed end trunnion open so that feed will get into the mill, and (2) keeping the rod charge low so rods will not work their way into discharge openings where they can cause rod
Read MoreClassification equipment may include ore sorters, gas cyclones, hydrocyclones, rotating trommels, rake classifiers or fluidized classifiers. An important factor in both comminution and sizing operations is the determination of the particle size distribution of the
Read More• the bond ball mill work indices determinations gave reasonably reproducible results, • significant variation was observed in the measurement of the bond rod mill work index on at least one sample tested, and • large variations in abrasion index and crushing work index were due to variations in the test method across the laboratories.
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