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 100% passing 6 mesh (), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
The ball mill grindability test is used for describing ore hardness and it is so widespread that the Bond Work Index generated from the test is often referred to as an ore characteristic. The ore resistance to grinding and energy consumption can be expressed using the work index and Bond's Third Theory.
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]. This measurement is expressed in kilowatthour per ton (kWh/t), which is the ...
For the ball mill grindability test, the work index is calculated from the following revised equation (in short tons): where: Pi = sieve size tested (microns) Gpb = ball mill grind ability Wi, P F have the same meanings as in the top equation. Equipment required: Laboratory ball mill, cm x cm with following ball charge: Agitator ...
The goal of this work is to create an equation to adjust a Bond ball mill work index from one P80 basis to another. The proposed model consists of two components, the variable coefficient that is ...
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.
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 ...
The Bond Ball Mill Work Index (Wi) is one such spatial estimate which remains difficult to infer correctly. The Wi defines the specific energy (kWh/ton) required in grinding a ton of ore in the ball mill from a very large size (infinite) to 100 m (Lynch et al. Citation 2015). At the time of writing, this variable is of particular interest for ...
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 work index covering grinding of fine particles is labelled M ib. M ia values are provided as a standard output from a SMC Test® (Morrell, 2004a) 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
The P 80 of a ball mill work index test can be estimated if the P 100 is know based on this equation: Estimate grams per revolution when only P100 is known. NI43101 reports often provide P 100 and the work index. To estimate the other parameters, you can assume: the P 80 is × (P 100, µm)
The charge is milled with the standard Bond ball mill for a set time. A particle size analysis is performed on the feed and ground product, and a modified work index is calculated using a proprietary model. The Mod Bond results must be calibrated against sufficient standard Bond ball mill work indices, typically 10% of the total.
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 ...
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 ...
Semiautogenous plus ball mill has been the "work horse" of mills. SAG vs Ball Mill Advantages . AG SAG Mill Grinding Compared Which is Best ... Rod mill grindability tests for Work Index are run at 10 or 14 mesh, and ball mill Work Index tests are run at the desired grind if finer than 28 mesh. All the data obtained is evaluated and ...
In conjunction with the Bond ball mill work index they can be used to accurately predict the overall specific energy requirements of circuits containing: • AG and SAG mills. ... As a general rule Bond ball work index tests are recommended when SMC Tests® are carried out as this provides valuable additional information on the way that much ...
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).
• WiBM The Bond ball mill work index, in metric units. • WiRM The Bond rod mill work index, in metric units. • WiC The Bond impact crushing work index, in metric units. • Density The coarse particle density measured in either the Bond impact crushing work index test or the drop weight test, t/m³.
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.
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CERAMIC LINED BALL MILL. Ball Mills can be supplied with either ceramic or rubber linings for wet or dry grinding, for continuous or batch type operation, in sizes from 15″ x 21″ to 8′ x 12′. High density ceramic linings of uniform hardness male possible thinner linings and greater and more effective grinding volume.
Istilah BWI sendiri dapat disebut lagi menjadi Bond Ball Mill Work Index (BBWI) atau Bond Rod Mill Work Index (BRWI). Ini tergantung dari media gerus yang digunakan selama percobaan, apakah bola baja atau batang baja. Untuk menghitung BWI digunakan formula sbb: Dimana. Wi = Nilai bond work index yang dicari (kwh/ton)
Typical Mill Circuit Represented by the Bond Ball Mill Test. The procedure for the work index test bases the BW i value on the calculation of new fines generated in the test. This means that the fraction of fines in the feed should not influence the test result significantly, if at all.
A wet grinding ball mill in closed circuit is to be fed 100 TPH of a material with a work index of 15 and a size distribution of 80% passing ¼ inch (6350 microns). The required product size distribution is to be 80% passing 100 mesh (149 microns). In order to determine the power requirement, the steps are as follows: Example Calculation
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.
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.
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 100% passing size of < mm.
grams per revolution (Gbp) is the ball mill grindability. The ball mill work index, Wi (kWh/short ton) is calculated from the following equation (Bond 1961):1 The mill should be cleaned by either blowing air into it or wiping the interior with a cloth and or brush. The FC Bond ball mill is now ready for the next sample.
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.
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