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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 …
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In practice, it is possible to find materials of non-standard size that are finer than 3.327 mm.In this work, a procedure for the calculation of the Bond work index is suggested for cases when the ...
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The Bond Ball Mill Grindability test is designed to give a measure of the grinding characteristics of a material by finding the amount of size reduction resulting from a controlled energy input. ... Wi = work index of the material comminuted. It is a relative measure of the resistance of the material to fracture. F, P = feed and product 80% ...
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The Bond work index (Bond, 1960) is based on Bond's law, which states that the energy consumed is proportional to the 1.5 power of particle size rather than the square of …
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Generally Bond work index for mill dimensioning and controlling is measured by grinding a feed material of less than 3.36 mm (− 6 mesh) particle size under standardized conditions in a Bond's mill (Diameter × Length = 305 mm × 305 mm). Bond's method simulates closed-circuit grinding which is carried out in sections until the …
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The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial comminution plants designing. Determining the Bond work index value is quite complicated, timeconsuming and requires trained operating personnel and …
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The later values from 's "Basics in Mineral Processing 2015" (Bond worked for All-Chalmers, which is now ) gives the value for basalt as 17.10. All kwh/st. For a particular application or project to size a mill circuit it would be prudent to have the Work Index (also for abrasion or crushing) determined at a mineral processing laboratory.
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2.1. Materials This study was carried out on three ores from W mines and two ores from a Ta mine. ... The Bond work index most commonly referred to is the BBM work index. This value is obtained in a 12" × 12" laboratory mill running at …
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In the context of his 'Third Theory of Comminution', Bond (1961) has stated: "Work Index expresses the resistance of material to crushing and grinding. Numerically the Work Index is the kWh per ton required to reduce the material from theoretically infinite size to 80% passing 100 µm."
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2.2 Bond Ball/Rod Mill Work Index. Bond ball mill work index (BBMWI) test is a standard test used to measure the ball mill work, which is calculated in accordance with the procedure proposed by the Bond [21]. The BBMWI determines how much energy is needed to grind a sample of ore in a ball mill [22].
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The Bond work index of inhomogeneous materials can be measured generally with high deviation, because the components have highly different grindabilities. The Bond work index can be determined by many ways, some of them are as follows: with the traditional standard method in a (1) Bond-ball mill or in a (2) Hardgrove mill with the …
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Keywords: grindability; comminution; Bond work index 1. Introduction Determining the Bond index using the Fred Bond method [1,2] is considered the state‐of‐the‐art methodology for mill calculations and a critical process parameter in raw materials selection and grinding process control.
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This paper describes the methodology for the determination of the Bond work index when coarse or fine raw material is found in the initial sample (i.e. when the initial sample not less than 3.35 ...
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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 = 25400 x …
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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 …
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The most widely known measure of grindability is Bond's work index which was defined as the 'resistance of the material to grinding' and quantified the specific …
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Avg Bond Work Index: kWh/t: kWh/t: kWh/sh.t: kWh/t: kWh/t: kWh/t: kWh/t: Range: No of Tests: Alumina: 17.9: 7-34: 6: Andesite: 20.1: 18.3: 20.1: 19.5: Barite: 6.3: 4.7: 5.2: 5.0: 5.8: 4-9: 7: Basalt: 18.9: 17.1: 18.8: 19.0: 19.0: Bauxite: 9.7: 9.5: 8.8: 9.7: 10.0: …
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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: 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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A 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 the energy required ...
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Bond's work index is one of the mostly widely used metrics of mineral grindability. In spite of its ubiquity, users are often not aware of the nuances of the work index family: what …
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The Bond's work index of the above rock samples calculated from the Hardgrove index value has shown a variation from 7.7 to 10.3 kWh/sh.t. A correlation is found between the friability value and work index. The correlation coefficient of 0.93 between the friability value (S1) and Bond's work index, Wi = -18.193 Ln (S1) + 66.747 …
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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 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. If the breakage characteristics of a material remain constant over all size ranges, the calcul ated work
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This paper investigates grinding of mineral mixtures with different grindabilities in the Bond ball mill. Understanding the ore mixture grinding is of great importance in mineral processing. The energy required for …
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The Bond work index is widely used to estimate the power required to grind materials. Because of the difficulty in determination of this index, alternatives to the standard method have been developed by many researchers. ... The results of Bond Work index (BWi) tests of five materials with five closing screen size (P 1) of 63o 500 µm are ...
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D. Todorović Maja Trumić L. Andric V. Milošević Milan Trumić. Engineering, Materials Science. 2016. The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial….
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It is a well-known fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. In this study, a variability bysis is carried out with the Bond standard grindability tests on different critical metal ores (W, Ta), ranging from coarse grinding (rod mills) to fine grinding (ball mills). The relationship between wi and grinding …
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Bond has suggested an intermediate course, in which he postulates that n is (-3/2) and this leads to: E = E i (100/L 2)1/2[1 – (1/q)1/2] (11.4) Bond defines the quantity E i by this equation. L is measured in microns in eqn. (11.4) and so E i is the amount of energy required to reduce unit mass of the material from an infinitely
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PDF | Bond's work index is one of the mostly widely used metrics of mineral grindability. In spite of its ubiquity, users are often not aware of the... | Find, read and cite all the...
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The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial comminution plants designing. ... 1981, Breake properties of some materials in laboratory ball mill, Powder Technology, 28, 235-241. BERRY T.F., BRUCE ...
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