Bond calls W i the "work index", literally meaning "energy index". Naturally, W i depends only, ... (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 125 mm. A continuous stream of ore was fed at the rate of 30 t/h.

energy impact work index (a.k.a. crushing work index) is conducted only on coarse specimens placed one at a time in the testing apparatus. With respect to the crushing work index test, F.C. Bond (1946) specifies that "In the standard method of testing only broken pieces that pass a 3-in. square opening and are retained

Abstract 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 ...

The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined media and ore charge. The Work Index calculated from the testing can be used in the design and analysis of ball mill circuits. The test requires a minimum of 10kg of sample that has been stage-crushed to passing size of <3.35 mm.

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 ...

Bond 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%.

test work. Bond work indices, obtained from bench-scale or pilot­ plant crushability and grindability tests are used in the fol­ lowing Bond equation (Bond, 1960) to determine the energy required to produce the required size reduction (1 ) Where W is the power requirements (kWh/st), Wi is the work index determined from comminution test­ ing,

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 ...

impact crushing work index – Crusher South Africa company profil pt.tapin coal terminal … Impact and Crushing work index tests…

Rittinger's crushing law states that. work required in crushing is proportional to the new surface created. Bond crushing law. calls for relatively less energy for the smaller product particle than does the Rittinger law. Work index is defined as the. gross energy (Kwh/ton of feed) needed to reduce very large feed to such a size that 80% of the ...

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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The crushing work index (CWi), estimated on the basis of the twinpendulum test, has been proposed by Fred Bond and accumulates a long track record in predicting the performance of crushing ...

You'll get a detailed solution from a subject matter expert that helps you learn core concepts. 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=. There are 2 steps to solve this one.

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

Crushing Law And Work Index - greenrevolution.org.in. 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 …

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

where 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.

An impact pendulum that follows strictly Bond's standard for crushability measurement (Bond, 1947, Bergstrom, 1985, Tavares, 2007) has been used, which allows calculating the crushing, or impact, work index.The test consists of dropping two pendulum-mounted hammers simultaneously against individual particles of size ranging …

A 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 ...

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?

Relationships other than Bond's third law have been … need for the hammer mill machine in our …. Bond F.C., 1961. Crushing and Grinding Calculations. by FRED C. BOND COMMINUTION theory is concerned with the … crushing rolls, and impact crushers, hammer mills or …. 'BoND, F. C. "Confirmation of the Third Theory", ….

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. Although considered an ...

The work index in Bond's law for crushing of solids has the following dimensions . No units (dimensionless) kWh/ton. kW/ton. kW m(^{1/2})/ton. ... A continuous grinder obeying the Bond crushing law grinds a solid at the rate of 1000 kg/h from the initial diameter of 10 mm to the final diameter of 1 mm. (i) If the market now demands ...

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 ...

Impact Work Index Procedure. This is or was used by to acquire the Impact (AKA Crushing) Work Index for sizing crushers. Use this in complement to the Bond Crushing Work Index …

For some comparative benchmarking information look at, Ballantyne, G.R. and Powell, M.S., Benchmarking comminution energy consumption for the processing of copper and gold ores. Minerals Engineering, 65, 2014, 109-114. Benchmarking comminution energy for copper and gold ores. Robert is correct, there are a couple of other frameworks also out …

Ore hardness can be estimated using commercially available standard techniques such as the SAG Power Index (SPI), Bond Work Index (BWI), and JK Drop Weight (JKDW) tests (Bailey et al., 2009 ...

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)

FIGURE 5: BOND ROD MILL WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS (MPa) 5 10 15 20 25 30 35 WiRM (metric) The lack of fit observed relating the crushing Work Index was expected to carry over to the other Bond Work Indices. Figure 5 displays the plot of rod mill Work Index (Wi RM) versus …