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
DetailsBOND 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)
DetailsThe 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.
DetailsSection 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 …
DetailsThe 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 …
DetailsBond Work Index c. Practical Energy Efficiency d. none of these. the initial and final sizes of the particles. ... Based on Bond's Crushing Law, the power required to crush a certain material will change by _____ if the diameter of the product is made smaller by 50% a. 50% b. 41% c. 25% d. 75%.
DetailsIt is a well-known fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. ... Bond's law for coarse grinding and secondary/tertiary crushing; and Kick's law for …
DetailsA linear relationship between grindability index, G, and friability value was found as given in Eq. (2). The correlation coefficient is very high, at 0.99. (2) G = 0. 171 + 0. 021 (S 20) The relationship between friability value (S 20) and Bond work index (W i) also has a high correlation of 0.97 and this relationship is given in Eq. (3). (3) W ...
DetailsUsing the Bond equation, compute the energy required to grind two tons of this ore. Refer to the following table for mesh aperture sizes in micrometers. Substituting the data for the initial run gives. The Bond work index of the ore has been determined. (This result closely matches the reference value for hematite given in Table 1.)
DetailsThe initial sample volume is 207 cm3 instead of 700 cm3; accordingly, the test can be performed on 3 kg instead of 10 kg. The procedure involves dry grinding in a closed cycle until a 250% circulating load is reached. The Bond work index is …
DetailsRittinger'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 done in crushing is proportional to the surface exposed by the operation; or, better expressed for this purpose, the work done on a given mass of rock …
DetailsThe Bond work index is defined as the specific energy required to reduce a particulate material from infinite grain size to a size of 100 microns (Stamboliadis, et al., 2011). Simply put, work ...
DetailsThe 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 ...
DetailsThe 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 sh…See more on 911metallurgist
WEBThe Bond rod mill and ball mill work indices are the most similar in size classes, both being fed material crushed to "relatively fine" …
DetailsAbstract and Figures. 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 ...
DetailsTitle: Bond F.C., 1961. Crushing and Grinding Calculations.pdf Author: can Created Date: 4/2/2009 4:00:03 PM
DetailsWork index is the relation between the SEC and the amount of breakage in an ore. The most common form of this relationship is given as Equation 1, and is often referred to as …
DetailsPerhaps 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 …
DetailsThe metal Bond ball mill is 30.5 cm inside diameter and. 30.5 cm inside length, with rounded corners. It is smooth except for the door hole used for charging. The grinding charge consists of 285 iron or steel balls (43 @ 36.8 mm diameter, 67 @ 29.7 mm diameter, 10 @. 25.4 mm diameter, 71 @ 19.1 mm diameter, and 94 @.
DetailsGeneralized Law : (n 2, 1 and 1.5 for Rittinger's, pp d (Dvs) vs Kik's and Bond's laws respectively) Work Index: the gross energy requirement in kilowatt hour per short-ton of feed (kWh/ton of feed) to reduce a very large particle to such a size that 80% of the product will pass through a 100 gm or 0.1 mm screen. — = 0.3162 w P Upp ] Lipp ...
DetailsThe word Bond is synonymous with grinding circuit design, e.g. Bond Grindability and Bond Work Index. Fred Bond's work on circuit design occurred from the late 1930s to the mid 1960s and it changed the method of design completely. In the pre-Bond era the prediction of the power required per tonne to grind material to a known …
DetailsThe 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 …
DetailsChapter 3 - Particle Technology (Size Reduction) Kick's law: the work required for crushing a given mass of material is constant for the same reduction ratio, ... 3.2.2 Bond crushing law and work index.
DetailsIn 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.
DetailsFor the evaluation of laboratory and industrial experiments, the work index can be determined as follows: BWI = 44.5 P 1 0.23 × G 0.82 10 P − 10 F where BWI = Bond's work index (kWh/sh. Ton), F = 80% passing size of original feed (μm), P = 80% passing size of circuit product (μm), P1 = Test-sieve size (μm) and G = Net grams of …
DetailsPreparation of Test Feed Sample for Bond Work Index Procedure: Riffle 8-10 kilograms of minus half an inch feed into 500 gram charges. Riffle one 500 gram charge of ore down to splits of 125 grams …
DetailsThe 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 …
DetailsMagdalinović [28] presented an abbreviated test for determining the work index based on performing two grinding cycles and relying on the law of first‐order kinetics. The test is …
DetailsThe traditional Bond work index proposed by F.C. Bond over 60 years ago is still today a useful tool for characterizing material crushability and grindability in the minerals industry.
DetailsThe 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 ...
DetailsBond crushing law. A. Calls for relatively less energy for the smaller product particles, than does the Rittinger law B. Is less realistic in estimating the power requirements of commercial crushers. C. States that the work required to form particle of any size from very large feed is proportional to the square root of the volume to surface ratio of the product
DetailsThe Bond low-energy impact test, also named impact work index or Bond impact crushing work index, can measure the crushing work index (CWI) and describes the competency of the ore at larger particle sizes. The Bond low-energy impact test calculates the actual crusher power requirements. The crushing work index (CWI) is …
DetailsThe Bond work index (BWI) is a well-known method used when selecting comminution equipment, to evaluate the grinding efficiency and to calculate the required …
Detailswhere Wi is the Bond Work Index, again in energy per unit mass 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.
DetailsThe 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 ...
DetailsPE series jaw crusher is usually used as primary crusher in quarry production lines, mineral ore crushing plants and powder making plants.
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