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 ...
Similar to a Comparative Work Index, this test is an open circuit dry batch grindability test run in the standard Bond Ball Mill for a set time. It can be used at mesh sizes from 65 to 200 mesh (normally 100 mesh). The test requires calibration against the standard Bond Ball Mill Work Index test to estimate the Work Index.
world. It shows that the ball mill work index is normally distributed with an average of and a median of kWh/t. bOnd rOd mill GrindAbility The Bond Rod Mill Grindability Test is performed similarly to the ball mill test. The feed sample is stagecrushed to ½" and the test is run under a circulating load. As in the ball mill ...
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 ...
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 ...
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
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
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 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). This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required ...
in a Bond ball mill for, 1, 2, 4, and 8 min. After each grinding cycle, the grinding product PSD is determined and returned to the mill for the subsequent grinding cycle.
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 ...
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.
In particular, the Bond work index (wi) is considered a critical parameter at an industrial scale, provided that power consumption in comminution operations accounts for up to 40% of operational costs. Despite this, the variability of wi when performing the ball mill Bond's standard test is not always understood enough.
The Bond's BallMill Work Index is a measure of the resistance of the material to grinding in a ball mill. This Index is widely used in the industry for comparing the resistance of different materials to ball milling, for estimating the energy required for grinding and for ball mill scaleup.
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 kilowatthours 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 ...
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
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.
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 .
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 ...
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 ...
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 Bond ball mill work index is one of the most commonly used grindability tests in mining, and is often referred to as the Bond work index. The test is a 'lockedcycle' test where ground product is removed from test cycles and replaced by fresh feed. The test much achieve a steadystate before completion.
Once finished the grinding cycles, a minimum of five, the ball mill Bond's work index w i [kWh/sht] can be calculated using Equation (2). In order to express it in metric tons, the corresponding conversion factor must be used. wi = 100 p 10 P80 p F80 (2) where: w i is the ball mill Bond's work index [kWh/sht];
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 ...
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 ...
The ball mill is designed to accept a ball charge in accordance with F. C Bond's standard. This ball charge consists of 286 balls as follows: 44 x 35mm balls; 67 x 30mm balls; 10 x balls, 71 x balls and; 94 x balls; Fully automated version of the Bond Index Ball Mill is also available on request.
© DZCrusher - كل الحقوق محفوظة
