W is the work index measured in a laboratory ball mill (kilowatthours per metric or short ton) P 80 is the mill circuit product size in micrometers; F 80 is the mill circuit feed size in micrometers. Buhrstone mill. Another type of fine grinder commonly used is the French buhrstone mill, which is similar to oldfashioned flour mills.
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 70 rpm, with rounded inner edges and without lifters. The grinding charge is comprised of a distribution of steel balls with several diameters. Table1shows the original Bond proposal [13], while the last Bond
mill, such as the Denver lab ball mill, to determine work index. Results obtained show that with an adequate adaptation of the. methodology, especially using a volume correction factor, the.
The ball mill performance was poor and could be indicated by only 59 % of< 125 µm (target product) in the discharge. ... Bond Ball Mill Work Index in kWh/t. Bond Rod Mill Work Index ...
Conclusions. The power model and linear model both will give reasonable P80 estimates given the P100 of a Bond ball mill work index test product. The power model might be marginally more robust ...
It is a wellknown 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 size did not show a clear ...
A Bond Ball Mill Work Index may also be used in the simulation and optimisation of existing mill(s) and the associated grinding circuit(s). Sample requirements: A minimum of 8 kg of material crushed to nominally minus 10 mm is preferred. JKTech would stage crush the sample to minus mm, as required for the Bond Ball Mill Work Index test feed.
The Bond Ball Mill Grindability Test (Bond, 1952, 1961) gives the Bond Ball Mill Work Index. This Index expresses the resistance of a material to ball milling; the higher the value of the Bond Ball Mill Work Index, the more difficult it is to grind the material using a ball mill. This Index is widely used in the mineral industry for:
Abstract The Frederick C. Bond has several grinding indices (ball, rod, abrasion), one of which has been a significant guide for ball mills. The Bond ball mill work index is an expression of the material's resistance to ground and a measure of the grinding efficiency.
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 timeconsuming (close to 5...
This study aims to develop a new approach toward estimating the Bond ball mill work index (BBWI) by applying a series of kinetic grinding tests with Bond standard mill. Establishing a series of ...
See other industries within the Manufacturing sector: Aerospace Product and Parts Manufacturing, Agriculture, Construction, and Mining Machinery Manufacturing, Alumina and Aluminum Production and Processing, Animal Food Manufacturing, Animal Slaughtering and Processing, Apparel Accessories and Other Apparel Manufacturing, Apparel Knitting Mills, Architectural and Structural Metals ...
See other industries within the Manufacturing sector: Aerospace Product and Parts Manufacturing, Agriculture, Construction, and Mining Machinery Manufacturing, Alumina and Aluminum Production and Processing, Animal Food Manufacturing, Animal Slaughtering and Processing, Apparel Accessories and Other Apparel Manufacturing, Apparel Knitting Mills, Architectural and Structural Metals ...
The guideline reviews the data required for analysis including hardness characterization data generated from the SMC Test® and the Bond Ball Mill Test Work Index, and the Morrell equations and their applications. This guideline is intended for those looking for a detailed breakdown of the Morrell method and equations.
Use this online formula to calculate a Ball Mill, Rod Mill or SAG Mill Operating Work Index. Based on Fred Bond's work you can estimate the energy used into your grinding circuit. This is the most accurate and informative method, but much of the data necessary for its application is not yet available.
C) for coarse rocks (7550 mm), a rod mill work index (Wi RM) for intermediate sized particles (253 mm), and a ball mill work index (Wi BM) for small particles (<3 mm) (Ammtec, 2000). Laboratory testwork is required to determine these Work Indices, and each test requires carefully collected samples of rock that is representative of future mill ...
and the Bond Ball Mill Work Index Test (GMG, 2021). The sampling and surveying guideline (GMG, 2016) pro vides addi tional detail on how to collect the required data and is critical to this analysis.
i is the ball mill Bond's work index [kWh/sht]; P100 is the mesh size used to close the grinding circuit [ m]; gbp is the grindability index [g/rev]. It has been recently proposed gbpbe renamed as the Maxson index [14]. Walter Maxson led the first research in which gbp was named as the grindability index [1], and was also
This is because work index frequently changes as a function of the product size in comminution. If target grind size during a project is changed, or if the test is run at the wrong product size, then it is necessarily to provide a correction. The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis
The results of the "raw" Bond ball mill work index values for dacite, basalt, and copper ore samples on coarse and fine samples are shown in Table 1. The raw work index is computed using Eq. (10) for the laboratory test results for both "valid" (F 100 = mm) and "invalid" (F 100 ≠ mm) feed to the test.
work index covering grinding of fine particles is labelled M. ib (Morrell, 2008). M. ia. values are provided as a standard output from a SMC Test ® (Morrell, 2004. a) whilst M. ib. values can be determined using the data generated by a conventional Bond ball mill work index test (M. ib. is NOT the Bond ball work index). M. ic. and M. ih ...
The Bond work index, W i, is defined in a Bond ball mill on the samples of standard size − + 0 mm. In practice, it is possible to find materials of nonstandard size that are finer than mm.. In this work, a procedure for the calculation of the Bond work index is suggested for cases when the Bond grindability test is conducted on samples of nonstandard size.
Many researchers have tried to find alternative methods for determining this Index to reduce labor costs, sample weight, or to get one without standard equipment. This paper was carried out with the purpose of reviewing, classifying and testing the existing methods for determination the Bond Ball Mill Index.
The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a predefined 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 stagecrushed to passing size of < mm.
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 Bond Ball Mill Grindability The sample was crushed to passing 6 mesh (), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
The work index can either be measured in the laboratory (the Bond ball mill work index determination is a common example) or it can be calculated from the operating performance of a milling ...
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