Question: Bond crushing law and work index Bond has suggested a law intermediate between Rittinger's and Kick's laws, by putting p= -3/2 in equation 2.1. Thus: E = 20 acਊਣ ਦ) 20/(2)(:-) = 20 (2.5) where: L 9= plz show me with steps how to …
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The Bond Crushing Law calculator calculates the energy required for crushing of a solid material based on Bond's Law. It helps in predicting the energy needed to reduce the …
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The Bond low-energy impact crushing work index (more informally, the Bond crushing work index) is not as common as the Bond ball mill work index, and it is a notoriously noisy test. The test is a 'per-specimen' test where individual specimens of prepared rock are hand-picked by the test operator and placed into the apparatus. Typically twenty ...
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created, Rittinger's Law fits the experimental data better. Bond's law • The work required to form particles of size Dp from very large feed is proportional to the square root of the surface to volume ratio of the product • P/f = 0.3162 wi 1 …
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The Bond Work Index is material specific and is obtained from laboratory crushing tests on the feed material. Hard and brittle materials have a work index in the range 4 × 10 4 − 8 × 10 4 J/kg. Bond's law holds reasonably well for a variety of materials undergoing coarse, medium and fine size reduction. (Eq. 14.3a) can also be reduced to
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bonds crushing law and work index. 20131254 epeat steps 2 and 3 heory and Analysis The minimum energy required for crushing of the sample is smaller than it onds law is often written in terms of the work index (Wi). Worksheet 1 8 Power Laws - …
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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.
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Rittinger's theory and law of the energy expended in crushing of rock is that the work of crushing is proportional to the reduction in diameter; or, as I have more fully expressed it: "The work …
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The Bond' Crushing Work Index is common to calculate the power needed to crush rocks from a given F80 size to a resulted P80 product size. Bond's impact method comes from a double mirrored pendulum impact crusher test on <76mm but >51mm (3″ and 2″) square rock pieces.
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The Pendulum Tester / Bond Impact Crushing Work Index Tester. Working principle Crushing by impact. 76 mm maximum feed size. Test repetition: At least 10, preferably 20 test runs. Adjustable crushing angle Repeatable crushing results Safe two-hand operating buttons The Bond Crushing Work Index (CWI) describes the competency of the ore at …
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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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Learn about the Bond work index, a parameter to measure ore hardness based on Bond's law of energy consumption. Find chapters and articles on comminution, Bond tests, and …
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Learn about the three Bond work index tests (ball, rod, crushing) and the Bond abrasion index for predicting ore hardness and …
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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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The oldest theory given by Von Rittinger is suitable for 10–1000 μm fine grinding range, Kick's law suitable for crushing range above 1 ... 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. ...
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BOND, F.C., 1961. Crushing and grinding calculations. Allis Chalmers Publications, No. 07R9235B. ... The Bond work index (BWI) is a well-known method used when selecting comminution equipment, to ...
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The Bond crushing work index test is an inherently poor test and has been shown time and time again in Round Robin studies to have poor precision (repeatability). Angove and Dunne's paper on the subject gives results that show factors of over 2 in terms of reported work index values from the same sample from different labs. Coupled with the ...
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Bond terms E i the work index, and expresses it as the amount of energy required to reduce unit mass of material from an infinite particle size to a size L 2 of 100 μm, ... (Kick's law) to crush the same limestone having a mean size of 2 mm. Assume all material charged had to be crushed. 4.11. The closed set of an operating jaw crusher was ...
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Perhaps the most traditional is the one proposed by F.C. Bond over 60 years ago (Bond, 1947, Bergstrom, 1985), which is still used today for characterizing material crushability in the minerals industry. The Bond crushing work index is a measure of material strength and is determined using a simple twin pendulum apparatus and a …
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Sizing a crusher can be done reliably calculated thanks to the Impact/Crushing Work Index and the testwork research done by Fred Chester Bond and his 1952 paper. According to Bond's Third Theory of Comminution, the work/energy input is proportional to the new crack tip length created during particle breakage and …
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The table also includes the Bond Work Index, which is discussed in the next section. An initial size reduction from material several centimetres in diameter down to one …
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terms. The index is defined as the energy required to crush from infinite size down to 100 µm, hence the 10 inside the brackets. Bond's Work Index values, in kWh per short ton: i.e. 2000 lbs or 907 kg, roughly follow the Moh's scale of hardness, see Table 11.1. In Summary, Kick's law is better for larger particles and Rittinger's
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Title: Bond F.C., 1961. Crushing and Grinding Calculations.pdf Author: can Created Date: 4/2/2009 4:00:03 PM
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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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As the initial velocity of the rebound block pendulum is zero, applying Newton's law of conservation of energy, ... Bond's crushing work index of gypsum. 3.4. A sample of granite passing a 7.5 cm square opening screen was suspended in a Bond's pendulum test. The length of the pendulum was 413 mm and the mass of hammers is …
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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. ... Bond, F.C., 1961. Crushing and grinding calculation part I and II. Brit. Chem. Eng. 6 (6 and 8). 378–385 & 543–548. Google Scholar. Chandar et al., 2016. R.K ...
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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 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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Understanding where the work index fits into the family of power-based grinding metrics will help operators correctly apply the work index and avoid making mistakes.
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Therefore, this measure can be cheaply determined using other rock characteristics. In addition, the value of the BWi determines the energy required for crushing and milling (depends on the BWi type, e.g., crushing work index, Bond ball mill work index, and Bond rod mill work index), and this measure can be used to optimize …
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In spite of being called Bonds Law, the work index equations are not a law of nature; but rather an empirically ... Stage crush the ball mill test feed sample and screen through a 3.36 mm (6 Tyler mesh) screen. Avoid over-crushing by screening, then crushing the oversize successively until it all passes the 3.36 mm screen.
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As a fast method, the determination of the Bond index from the Hardgrove index (by calculation) is almost matching with measured Bond's work index. The Bond's work index of the above rock samples ...
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law for fine grinding; Bond's law for coarse grinding and secondary/tertiary crushing; and Kick's law for primary crushing). The novelty in the third law's proposal was the proce‐ dure for determining wi in the case of crushing, rod milling and ball milling [13,15]. The
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The tested rock sample of a 500 g aggregate in the fraction 11.2–16.0 mm was inserted into the mortar.The friability value S 7 equals the percentage of undersized material, which passes through the 11.2 mm mesh after the aggregate test crushing in the mortar by weight-drops, the mean value for a minimum of three to four parallel tests …
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GSL offers a range of Bond Work Index Testing from crushability and abrasion to ball and rod mills. For more information on the tests please see below: Bond Low Energy Impact Test. The Bond Low-Energy Impact test can be used to determine the Crusher Work index (CWi), also known as the Impact Work Index. The test determines the impact energy at ...
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Section snippets Grinding kinetics in the Bond ball mill. Tests of grinding kinetics in the Bond ball mill (Fig. 1, Fig. 2) has shown that over a shorter grinding period, the process follows the law of first order kinetics R = R 0 e-kt where R = test-sieve oversize at the time (t); R 0 = test sieve at the beginning of grinding (t = 0); k: grinding rate …
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Work index is a material parameter that indicates the difficulty of ore crushing or grinding in mineral processing. Learn about the different types of work …
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