2009-1-1 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 for grinding, and for ball mill scale-up.
2015-6-6 This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Work Index of minus six mesh or finer feed ore samples. These
This happens after 7–10 grinding cycles, which shows that the procedure is a lengthy and complex one and is therefore susceptible to procedural errors. Starting from the first-order grinding kinetics defined by means of the Bond ball mill, this paper discusses a simplified procedure for a rapid determination of the work index by just two
Numerically, the work index is the energy required in kwh/t to reduce a given material from theoretically infinite feed size to 80% passing 100 microns. The work index of a particular material is determined in the laboratory by conducting the standard Bond grindability test. Bond developed separate tests for the rod mill and the ball mill.
2013-1-1 To calculate Bond rod-mill work indices, the four samples were screened and the particle size distributions plotted in Fig. 2.The plot was used to find F 80 of the samples for calculations. Fig. 3, Fig. 4 show the grinding kinetics of Pb, Cu, Fe, and Mn ores in the Bond rod-mill in different test-sieves. The slopes of all lines in the figures are equal to the k value of Eq.
The ball mill work index laboratory test is conducted by grinding an ore sample prepared to 100% passing 3.36 mm (6 mesh) to product size in the range of 45-150 µm (325-100 mesh), thus determining the ball mill work index (WiB or BWi). The work index calculations across a narrow size range are conducted using the appropriate laboratory work index determination for the material size of interest, or by chaining individual work index calculations using multiple laboratory work index determinations across a wide range of particle size. To give a sense of the magnitude, Table 5.1 lists Bond work indices
2016-12-27 micrometers in size. According to the Bond standard procedure, the work index is determined by simulating a dry grinding in a closed circuit in the Bond ball mill to achieve 250% circulating load (Bond, 1949, 1952, 1961). The test is performed on a raw material approximately weighing 10 kg, which coarseness is 100% -3.327 mm. The first grinding test is performed on a 700
2015-11-11 Kinetic grinding test approach to estimate the ball mill work index 343 The W i parameter is obtained from Bond’s ball mill grindability test (Bond, 1961). This test is performed according to the standard Bond procedure which proposed model is presented in Eq. 1. This standard grindability test simulates a closed-cycle
The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and
2016-7-14 The work index expresses the resistance of the material to grinding. It represents the kilowatt hours per tonne required to reduce the material from theoretically infinite feed size to 80 passing 100μm (Wills and Napierpercent -Munn, 2006). Bond devised several methods for predicting ball-mill and rod-mill energy requirements and
2017-1-7 in the design of a grinding circuit. 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 100% passing 6 mesh (3.35mm), from this a 700 cc volume was measured and weighed to be used
cycle test akin to the Bond Ball mill work . index determination. The first cycle starts with minus 6 mesh ore removed since it is believed that the fines content can fill most of the voids allowing little room for rock breakage and piston movement. Without adequate piston
A quick procedure with two grinding cycles for the determination of the Bond. work index approximate value is exactly the same as in the first two grinding cycles of. the standard Bond test and
2020-10-13 Starting from the rst-order grinding kinetics dened by means of the Bond ball mill, this paper discusses a simplied procedure for a rapid determination of the work index by just two grinding tests. The applicability of the simplied procedure has been proved on samples of
1998-11-1 Rowland, C.A., 1978, “Determination and use of operating work indices in controlled grinding circuits–A proposed concept,” Mill Operator’s Conference and Exhibit, Northwestern Branch, Australasian Institution of Mining and Metallurgy, Mt. Isa, Queensland Australia, June. Google Scholar
2 天前 You need a two-stage solution, first stage open-circuit mill and then second stage closed-circuit 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 (+2.1 mm) and the Bond ball mill work index for the fine component (-2.1 mm).
The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial comminution plants designing. Determining the Bond work index value is quite complicated, timeconsuming and requires trained operating personnel and therefore is subjected to errors.
2020-9-24 Where, WioACTis the Actual Operating Bond Work Index (kWh/t), W is the specific energy input (kWh/t), P80 is the 80% passing size of product (µm), and F80 is the 80% passing size of circuit feed (µm). 2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal
The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill. Chat Online; Determination of Bond Work Index of Lucky Cement
2016-7-14 The work index expresses the resistance of the material to grinding. It represents the kilowatt hours per tonne required to reduce the material from theoretically infinite feed size to 80 passing 100μm (Wills and Napierpercent -Munn, 2006). Bond devised several methods for predicting ball-mill and rod-mill energy requirements and
2020-10-13 Starting from the rst-order grinding kinetics dened by means of the Bond ball mill, this paper discusses a simplied procedure for a rapid determination of the work index by just two grinding tests. The applicability of the simplied procedure has been proved on samples of
The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined 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 stage-crushed to 100% passing size of <3.35 mm.
Determination of the Bond Work Index of Ores A.J.C.Taguiam Department of Mining, Metallurgical and Materials Engineering University of the Philippines, Diliman [email protected] Abstract The Bond work index refers to the measure of a material’s hardness or resistance to crushing and grinding, and is numerically expressed as kilowatt hours per short ton.
2018-2-20 Bond Test WI’s (kWh/t): Rod Mill: Ball Mill: 9.5 kWh/t.8 9 kWh/t . Bond Standard Circuit Work Index: Assume the rod mill Work Index of 9.5 applies from the actual rod mill feed sizeof 19,300 mµ (although some of this work might ideally be done by crushers to achieve a rod mill
2014-3-6 Bond index is useful in designing of grinding system in mineral processing. In this study, the Bond work index of Birnin- Gwari iron ore in northern Nigeria is determined using modified Bond’s method using ‘reference ore’. Samples of iron ore were sourced using random method, reference minerals; marble and granite of known weight and iron ore of known weight were ground using the
The Bond Index conforming rod charge consists of: 6 rods of 1.25“ diameter and 21“ length. 2 rods of 1.75“ diameter and 21“ length. The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill.
2013-12-24 (Magdalimovic,1989). Numerically the work index is the energy required in Kwh/short ton to reduce a given material from theoretically infinite size to 80% passing size of 100 microns (Onemine, 2009). The determination of work index using modified Bond’s method can be compared to method of determining it by Berry and Bruce (1966).
Ball Mill Wio, BWio 8.6 Circuit Wio, OWio 14.6 Bond Ball Mill Work Index, BWi, kWh/t 13.4 Bond Rod Mill Work Index, RWi, kWh/t 18.1 Table 1. Example of AG/SAG Ball Mill Circuit Wio Calculations [1] [2] ABstrAct Optimum use of power in grinding, both in terms of grinding efficiency and use of installed capital, can have a large effect on
2020-1-3 Grinding Studies. Two kinds of mills, BBM and LBM, were used to achieve the desired P 80 passing percentage of 150 μm with an acceptable range of hematite liberation (> 75%) at optimum grinding time. The BBM is a standard ball mill having a length and diameter of 300 mm × 300 mm with smooth liner as shown in Fig. 2.A rotating drum is attached to a gearbox and has adjustable speed knob.
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