You need a twostage solution, first stage opencircuit mill and then second stage closedcircuit mill. First stage, will be broken into two parts as well, you use a Bond rod mill work index for the coarse component of the ore (+ mm) and the Bond ball mill work index for the fine component ( mm).
The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index. For grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill (see Figure ), a question arises as to whether this practice will alter the ball mill work index (BW i) of the material ...
The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond Work Index, bulk density, specific density, desired mill tonnage capacity DTPH, operating % solids or pulp density, feed size as F80 and maximum 'chunk size', product size as P80 and maximum and finally the type of circuit open/closed ...
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:
A copy of Fred C. Bond's Method of Crushing and Grinding for determination of the Bond Index is included with each mill. This Ball Mill can be used continuously or it can be used for any number of revolutions, according to the type of grind desired. The FC Bond ball Mill comes with table stand, motor, clutch, revolution counter, motor starter ...
b) Bond Work Index Both Rod Mill (Wr) and Ball Mill (Wb) The Bond test is used to predict the energy required for coarse material grinding between the 80% passing feed size and the split size ...
A modified equation has been proposed to calculate the Bond Ball Grinding Index (BWI), that considers the ratio of the MSL14K mill net grinding power to the net grinding power of Bond ball mill.
Bond Work Index Ball Mill (BWi) The Bond Ball Mill Work Index (BWi) is used to calculate the power requirements to grind ore to a typical ball mill product. Table 3 shows the BWi for each composite. Table 3 ‐ Bond Ball Mill Work Index Sample ID Closing Screen Size (μm) F80 (μm)
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 hours ...
Section snippets Material and experimental Bond tests. Samples of dacite and basalt from Serbia, copper ore from a South American metasedimentary copper mine, and copper porphyry ore from Canada, of different feed sizes, were used to determine the Bond ball mill work index according to the standard standard Bond laboratory mill with "DxL = 305 × 305 mm" balls and rotation ...
The Bond ball mill test is used to determine the socalled standard work index, which is defined as the specific energy consumption (in kWh/t) required to reduce a material from a notional ...
properties of ores include the Bond ball mill work index and the Bond rod mill work index.
. These are empirical indices determined by closed circuit grindability tests developed by
. in the mid 1930's. They require a specific 305mm diameter x 305mm long (inside dimensions)
.
However, the ball diameters vary due to wear. Therefore, the total ball number should be adjusted from time to time to ensure a total mass of grams. The grinding jar of the Bond Index Ball Mill measures 12″ x 12″ and has wellrounded corners. Module Rod Mill. Minerals precrushed to < mm and sieved ; Drillcore precrushed to ...
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.
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 ...
The Bond ball mill grindability test is run in a laboratory until a circulating load of 250% is developed. It provides the Bond Ball Mill Work Index which expresses the resistance of material to ...
A Bond Ball Mill, 12" x 12" of fabricated construction comes with electric motor and gear reducer drive, digital counter, jogging button to provide positioning of drum for loading and unloading, emergency stop button, 44 ½ lb ball charge, stand and receiving pan. Perform Fred C. Bond's grindability tests with this standard BWI test ball mill.
The Work Index (BWi) is calculated according to Fred Bond's Equation. Bond Work Index for Testing Procedure. Cleaning and Storing of Ball Mill Charge after the Bond Work Index Procedure is done: Add about 500 g of silica sand into the mill containing the ball charge. Seal the mill. Rotate for 20 revolutions to clean.
µm. Note that—in order for no correction factor for ball mill product fineness to apply—the ball mill circuit P80 should be no less than approximately 70 µm (Bond, 1962). This Bond Efficiency determination should not be applied to circuits with a P80 finer than approximately 70 µm without making qualifications. 3.
An alternative mill ball charge is proposed that closely approximates Bond's original total ball mass, number of balls and ball surface area. Results of 30 Bond Work index tests of six pure materials (calcite, magnesite, labradorite (feldspar), quartz, andalusite and glass) using closing screen apertures (P 1 ) values of 500, 250, 125, 90 and ...
The Bond ball mill work index (Wi BM, or BWi) conducted from a feed size of approximately 2 mm to a product size on the order of 100 µm. The Bond rod mill work index (Wi RM, or RWi) conducted from a feed size of approximately 10 mm to a product size on the order of 1 mm. The Bond crushing (impact) work index (Wi C, CWi, LEIT or IWi) conducted ...
Based on the standard procedure defined by Bond, the ball mill work index is determined by simulating a closed cycle dry grinding in a laboratory Bond ball mill until a stable circulating load of 250% is established (Bond, 1949, Bond, 1952, Bond, 1961). The ball mill work index is determined by Eq. (10). The recommendation is the ball mill ...
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.
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.
Key words: Comminution, Bond work index, Grinding, Crushing, Ball mills, Rod Mills. Theoretical efficiency In their book Process Engineering of Size Reduction Ball Milling, Austin, Klimpel and Luckie (1984) stated that, "We have tried throughout this book to avoid the use of the term grinding efficiency because the degree of conversion of
Essa® Bond TestWork Equipment. Internationally accepted mineral metallurgical standard test procedures to determine the physical properties of ores include the Bond ball mill work index and the Bond rod mill work index. These are empirical indices determined by close circuit grindability tests developed by in the mid 1930's.
Process Engineering of Size Reduction: Ball Milling. Society of Mining Engineers of the American Institute of Mining, Metallurgical and Petroleum Engineers (AIME) Inc, ISBN, New York, 556 pp.
Bond ball mill w ork index test is used to ca lculate the work index rel ated to fine grinding (Mib). Mia and Mib are used to cal culate Ecs for the coarse (Wa) and fine (Wb) components acc ording .
A Bond Work index mill ball charge and closing screen product size distributions for grinding crystalline grains. Int. J. Miner. Process., 165 (2017), pp. 814, / View PDF View article View in Scopus Google Scholar. Menéndez et al., 2018.
Fred Bond published an article in 1961, which, described the procedure for testing ores for a Bond Ball Index. This parameter is still one of the most demanded tools in the design, evaluation and optimization of ball grinding plants around the world. However, the testing methodology for the Bond Dall Index requires about 10 kg of
samples and perform the rod mill test on the samples blend. Bond Ball Mill (BBM) Standard Test The procedures to carry out the Bond grindability tests in ball mills and rod mills are outlined in They are usually referred to as the standard tests, but it must be highlighted that the procedures haven't been defined by ...
HGI vs Bond Index Test Bond Index HGI Mill Comparison Tube Ball mill Babcock mill (ringball) Target Particle Size Any size below 75µm Particle Size Range < (powder) or pellet size µm Mass constriction Volume 700ml Mass 50g Output kWh/ton HGI Index Suitable materials Any Good quality coals
Design engineers generally use Bond Work Index and Bond energy equation to estimate specific energy requirements for ball milling operations. Morrell has proposed different equations for the Work Index and specific energy, which are claimed to have a wider range of application. In this paper an attempt has been made to provide a comparison of these two approaches and bring out their ...
The ball mill work index laboratory test is conducted by grinding an ore sample prepared to passing mm to product size in the range of 45150 µm, thus determining the ball mill w i .
Bond Ball mill work index determination (1 reply) s. srinu1234. 5 years ago. srinu1234 5 years ago. Dear all, Have a good day! I am trying to determine ball mill work index for a very soft . If I follow bonds procedure to do experiment, not able to determine. The following is the data of ore sample. F80% = 2300mic.
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