Fig. 1. Ores for the work index test: a) type and b) feed size 2.2. Ball mills and operation conditions Fig. 2(a-d) shows the ball mills used in the determination of the Work Index (standard mill BBM and non-standard mills BM-1 to BM-3, all ball mills without lifters). Bond standard ball mill (Fig 2(a);
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the Bond Work Index (kWh/t) can be rapidly estimated (less than 2 hours) and show a high accuracy for mills of non-standard dimensions (R2= 0.96). Keywords: Bond´s Work …
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JK Bond Ball Mill Test Since its introduction in the 1960s, the Bond Ball Mill Work Index (BBMWi) parameter has been extensively used in predicting ball mill power draw. Use of Work Index Along with comminution circuit design the work index parameter is widely used in tracking mill performance. Due to the age and lack of controls for the test,
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Based on the standard procedure defined by Bond, the ball mill work index is determined by simulating a closed cycle dry grinding in a laboratory Bond ball mill until a stable circulating load of 250% is established (Bond, 1949, Bond, 1952, Bond, 1961). The ball mill work index is determined by Eq. (10). The recommendation is the ball mill ...
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An analysis of the results shows a direct relationship between the Bond work index and the Denver work index when the Bond test is defined adequately to the Denver lab mill. Comparison of results ...
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The Work Index is used when determining the size of the mill and grinding power required to produce the required ore throughput in a ball mill. 2. Procedure 2.1. Bond Ball Mill Grindability The sample was crushed to passing 6 mesh (3.35mm), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
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The computation of a Bond ball mill work index was empirically calibrated by Fred Bond using a short ton basis. The modern (metric tonne) basis is the following equation: Derived values composed from Wi BM results. Morrell Mib value is calculated for a sample if the following are available: umClosing, F80, P80, gpr.
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1.. IntroductionA Bond Ball Mill Work Index test is a standard test for determining the ball mill work index of a sample of ore. It was developed by Fred Bond in 1952 and modified in 1961 (JKMRC CO., 2006).This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating …
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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. ... GSL can carry out Bond Rod Mill Work Index tests to determine the energy requirements for milling ore in a rod mill. The test requires a minimum of 20kg of -12.5mm material. Closing screen sizes typically range from ...
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The bond work index for a mesh-of-grind of 200 mesh for a rock consisting mainly of quartz is 17.5 kWh/ton. How much power in kW is needed to reduce the material in a wet-grinding ball mill from an 80% passing size of 1100 µm to an 80% passing size of 80 µm at a capacity of 10 ton/hr?
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A modified equation has been proposed to calculate the Bond Ball Grinding Index (BWI), that considers the ratio of the MSL-14K mill net grinding power to the net …
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The commonly used grindability tests included in the database are the Bond work indices for ball milling, rod milling and crushing; the drop weight test results A, b, A×b, DWi, Mia, Mic, Mih and ...
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Learn how to perform a Bond Work Index Test or Bond Ball Mill Work Index Test to determine the grindability of ore samples. Follow the steps, equations and examples to calculate the Bond Work Index and the grindability of the ore.
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When accurate mill ore feed rate in dry tons per hour, mill power draw in kilowatts, and mill feed and product size analyses in microns are available the Bond Equation can be used to measure the operation of comminution machines, reporting it as operating work index. The equation for operating work index as given in the paper …
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Differences up to 6,2% in the Bond ball mil work index can be observed due to different siz distribution in P 80 calculation.. 13 ores were tested using the Bond ball mill grindability test, obtaining P 80 using different interpolation functions. Rosin Rammler's model showed the best behavior, so its use must be not only suggested, but …
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The basic work index equation is: W = 10 Wi/√P – 10 Wi/√F(1) where W is the work input required in kilowatt hours per short ton to grind from 80% passing F microns to 80% passing P microns, and Wi is the work index, or the grinding resistance parameter. It represents the energy input required in kilowatt hours to reduce a s…
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The Bond ball mill work index is one of the most commonly used grindability tests in mining, and is often referred to as the Bond work index. The test is a 'locked-cycle' test where ground product is removed …
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The self-grinding work index is an extension of the concept of Bond work index. It generally refers to the work index calculated by using Bond's fracture theory on the principle of ore crushing energy consumption according to the W, F, and P data of a small or semi-industrial or industrial self-grinding test. In this kind of test, McPherson …
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The FC Bond Work Index Test Ball Mill was designed by F. C. Bond for use in determining the Bond Index, a measure of grindability and power required for grinding applications. The FC Bond Mills are used in laboratories throughout the world. A copy of Fred C. Bond's Method of Crushing and Grinding for determination of the Bond Index …
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BOND WORK INDEX. 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: …
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In Grinding, selecting (calculate) the correct or optimum ball size that allows for the best and optimum/ideal or target grind size to be achieved by your ball mill is an important thing for a Mineral Processing Engineer AKA Metallurgist to do. Often, the ball used in ball mills is oversize "just in case". Well, this safety factor ... title="Calculate …
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The Bond Work Index approach is the standard method of selecting ball mills to grind from about 3 mm to 25 µm provided that correction factors are used if …
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The test determines the Bond Impact Work Index which is used with Bond's Third Theory of Comminution to calculate net power requirements when sizing crushers*. It is also used to determine the required open-side settings (jaw crushers and gyratory crushers) or closed-side settings (cone crushers) for a given product size.P80 = …
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Introduction. The Bond grindability test for determining the Bond work index, W i, is conducted in a Bond ball mill having the dimensions D × L = 305 × 305 mm and a speed revolution of 70 min − 1.The mill is loaded with balls from 15.5 up to 30.6 mm in diameter, having thus a total mass of 20.125 kg.. This test simulates a closed circuit of …
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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 ...
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For the ball mill grindability test, the work index is calculated from the following revised equation (in short tons): where: Pi = sieve size tested (microns) Gpb = ball mill grind ability Wi, P & F have the same meanings as in the top equation. Equipment required: Laboratory ball mill, 34.02 cm x 34.02 cm with following ball charge: Agitator ...
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The grinding-product size, P, in a Bond ball mill, ... (1961), is deter- mined by the formula: / 10 10 (I) The work index is determined by grinding experiments carried out in a labo- ratory Bond ball mill. Based on the results of grinding experiments, numerical values of the work index Wi are calculated according to the formula: 0301-7516/89 ...
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The grinding-product 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 ...
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It is commonly known that one must run the Bond ball mill work index test such you pick a closing mesh to give a P 80 close to desired grind size.
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particle size are calculated and the Bond ball work index is then calculated using the standard Bond ball work index formula: 𝑊𝑖= 44.5 𝑃0.23·𝑔𝑏𝑝0.82·[10 √𝑃80 · 10 √𝐹80] [2] where W i represents the Bond ball work index, F 80 and P 80 …
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The Bond Work Index (Wi) is a common technique for the estimation of hardness and energy requirement for comminution using ball mills. However, this technique is time-consuming (close to 5 hours ...
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