Analysis of normalized test results show, with a correlation factor R² of 0.9956, that the revolutions required in all the Bond Work index mill tests conducted (29–419 revolutions) corresponds ...
In practice, it is possible to find materials of non-standard size that are finer than 3.327 mm.In this work, a procedure for the calculation of the Bond work index is suggested for cases when the ...
To calculate the Bond work index ( Wi) in a standard laboratory scale rod-mill, Bond derived the following equation: (1) W i = 62 P i 0.23 G i 0.625 10 P - 10 F kw h sh t where F is 80% passing size of original feed, P is 80% passing size of circuit product and Pi is the test-sieve size in μm [1]. The standard procedure to determine all Bond ...
Bond's work index is one of the mostly widely used metrics of mineral grindability. In spite of its ubiquity, users are often not aware of the nuances of the work index family: what …
= fine ore work index (kWh/tonne) P. 1 = closing screen size in microns . Gbp = net grams of screen undersize per mill revolution . p. 80 = 80% passing size of the product in microns . f 80 = 80% passing size of the feed in microns . Note that the Bond ball work index test should be carried out with a closing screen size
1. Introduction. The Bond grindability test for determining the Bond work index, W i, is conducted in a Bond ball mill having the dimensions D × L = 305 × 305 mm and a speed revolution of 70 min − 1.The mill is loaded with balls from 15.5 up to 30.6 mm in diameter, having thus a total mass of 20.125 kg.. This test simulates a closed circuit of …
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…See more on 911metallurgist
WEBBond's work index is one of the mostly widely used metrics of mineral grindability. In spite of its ubiquity, users are often not aware of the nuances of the work index family: what are...
standard Bond mill and a standard Bond grind test were used to determine the model parameters. The test is performed on a sample of mass M (g) that is 700 cm3 of size class 3.35 mm. The sample is ground at times of 0.5 min, 1 min, 2 min, and 4 min. After each grinding cycle, the analysis of the PSD is determined for the sample.
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 …
the Bond Work Index (kWh/t) can be rapidly estimated (less than 2 hours) and show a high accuracy ... Fig. 2(a-d) shows the ball mills used in the determination of the Work Index (standard mill ...
The FC Bond Work Index Test Ball Mill was designed by F. C. Bond for use in determining the Bond Index, a measure of grindability and power required for grinding applications. The FC Bond Mills are used in laboratories throughout the world. A copy of Fred C. Bond's Method of Crushing and Grinding for determination of the Bond Index is …
The Bond Ball Mill Work Index is a unique ball mill work index tester. It is used to determine the grind-ability of materials and help choose the most suitable type and grinding equipment. The grinding work index indicates the grind-ability of cement raw materials and mixtures. The principle of its measurement method is that after the materials ...
When Erf/Erp is greater than 1.29, the work index increases as the product size decreases, and when Erf/Erp is less than 1.29 the work index decreases. Eq. (8) suggests that a standard work index Wi100, or the work index at 80% passing 100 microns calculated from the exposure ratios, can be found from the following Eq. (9):
The grindability of an ore in the process of mineral dressing can be determined by use of the Bond work index ( Wi ). This index is determined on a laboratory-scale using a Bond ball-mill and by simulating dry grinding in a closed circuit until the 250% circulating load has been obtained. This happens only after 7–10 grinding …
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 …
Bond Rod Index Mill, 12" x 24" consisting of a one (1) piece cast shell complete with integral wave, 1 Hp 3/60/220 volt motor/gear reducer drive, support frame which allows the mill to tilt +/- 5 degrees during operation and 45 degrees for discharge (manual operation), receiving pan, rod charge and control panel complete with digital revolution counter, …
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.
Fig. 1. Ores for the work index test: a) type and b) feed size 2.2. Ball mills and operation conditions Fig. 2(a-d) shows the ball mills used in the determination of the Work Index (standard mill BBM and non-standard mills BM-1 to BM-3, all ball mills without lifters). Bond standard ball mill (Fig 2(a);
The results showed that using the non-standard mills (between 20 and 35 cm in diameter), the Bond´s model constants (α=0.23; β= 0.82, and γ = 44.5), are unable to predict the Work Index ...
This Table of Ball Mill Bond Work Index of Minerals is a summary as tested on 'around the world sample'. You can find the SG of each mineral samples on the other table. Source 1. Source 2. Source 3. Source 3. Source 4.
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 2.1. Bond Ball Mill Grindability The sample was crushed to passing 6 mesh (3.35mm), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
Calculate a Mill's Operating Work Index. 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 …
The most widely known measure of grindability is Bond Work Index (BWI) which was defined as the resistance of the material to grinding and quantified the specific work input (kWh/t) required to ...
Bond Work Index. The Bond work index (Bond, 1960) is based on Bond's law, which states that the energy consumed is proportional to the 1.5 power of particle size rather than the …
Introduction. The Bond grindability test for determining the Bond work index, W i, is conducted in a Bond ball mill having the dimensions D × L = 305 × 305 mm and a speed revolution of 70 min − 1.The mill is loaded with balls from 15.5 up to 30.6 mm in diameter, having thus a total mass of 20.125 kg.. This test simulates a closed circuit of …
The 1.2kg 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 …
For 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 …
The Bond rod mill work index is not as common as the Bond ball mill work index, and there are two different variations on the mill apparatus. The SAGMILLING models expect a mill with a "wave liner", and is not compatible with mills using "smooth liners". Most laboratories outside of Australia use the wave liner style of machine – these ...
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.