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 'locked-cycle' test where ground product is removed from test cycles and replaced by fresh feed. The test much achieve a steady-state before completion
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.COM models expect a mill with a wave liner , and is not compatible with mills using smooth liners
Bond Standard Circuit Work Index: Assume the rod mill Work Index of 9.5 applies from the actual rod mill feed sizeof 19,300 m (although some of this work might ideally be done by crushers to achieve a rod mill F80 of 16,000 m) to a rod mill (circuit) product size of 1,000 m. W Total = 2.32 + 4.77 = 7.09 very large size (FkWh/t of . 9.70
The mill power is = 22.5 Watts, calculated by (6). Fi- P nally the product is wet screened to find the size d80. 2.4. Rod Mill Semi Continuous Process The same mill is used for the semi continuous grinding tests which is similar to the Bond test but with the exist- ing mill of known power. After time the mill product is t
Commentary on the apparatus of the Bond rod mill work index The Bond Third Theory of comminution was originally divided into three size classes reflecting the varieties of comminution equipment common during the time period when Bond (and his collaborators) were gathering the information to calibrate comminution models
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
The work index obtained following the standard Bond grindability test described above predicts the energy requirement for a 2.44 meter (8ft.) inside liners diameter, prototype ball mill under the following conditions: 1. Wet closed circuit grinding. 2. Energy predicted is
Meaning of Indexing: Milling operations sometimes, require the rotation of job correct to fractions of minutes, for each groove, slot etc., to be cut evenly on the job surface. The accuracy of spacing of teeth is very important particularly when the work is of precision character e.g., gear teeth, shafts, cutter teeth etc
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Oct 24, 2018 The work index can either be measured in the laboratory (the Bond ball mill work index determination is a common example) or it can be calculated from the operating performance of a milling
JK Bond Ball Mill Test Since its introduction in the 1960s, the Bond Ball Mill Work Index (BBMWi) parameter has been extensively used in predicting ball mill power draw. Use of Work Index Along with comminution circuit design the work index parameter is widely used in tracking mill performance. Due to the age and lack of controls for the test
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The Bond ball mill work index test is thought to be additive because of its units of energy; nevertheless, experimental blending results show a non-additive behavior. [18] The SPI(R) value is known not to be an additive parameter, however errors introduced by block kriging are not thought to be significant
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
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 square of Rittinger’s law
1. A grindability measurement made in a laboratory work index apparatus, such as a ball mill work index (WiBM) or a rod mill work index (WiRM) 3. An operating work index (WiO): A measurement of a specific energy consumption and size reduction in an operating plant. 4. A generic work index that represents an intrinsic ore breakage characteristic that is
Jun 06, 2015 Bond Work Index Procedure and Method. 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 equation application methods are used to process 1/2″ ore samples in a Ball Mill using a standard ball charge. Below describes in general terms the Bond Work
Work index of 14.6 kWh/t, from the Bond Ball Mill is indicative of a hard ore. The hardness indexes are defined as follows: Property Soft Medium Hard Very Hard Bond WI (kWh/t) 7 - 9 9
Jun 19, 2015 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 Source 5 Source 6 Source 6 KWh/t Source 6; Avg Bond Work Index: kWh/t: kWh/t: kWh/sh.t: kWh/t: kWh/t: kWh/t: kWh/t: Range: No of
Dec 07, 2018 The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis to another. The proposed model consists of two components, the variable coefficient that is determined from a specific work index determination and a fixed exponent determined by a calibration procedure
The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test
Mar 31, 2016 A “Bond” rod mill work index is to be determined in an apparatus with a wave liner. The author is aware of four laboratories that offer a rod mill work index test where the lining of the mill is either smooth, or smooth with a small number of primitive lifters that do not constitute a wave liner (one of the four laboratories is known to be investigating replacing the liner with a
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
One is the Hardgrove grindability index and the other the Bond work index. The Hardgrove index is determined using the ASTM method D 409–71. It involves grinding 50g of the material, e.g. coal, of specified size (16–30 mesh cut) in a specified ball-and-race mill for 60 revolutions
Mill Ball Mill Closed circuit crushing to 16 mm Open circuit 8’ dia. rod mill to 1 mm Closed circuit 8’ dia. ball mill to P80 um The ore Test Work Index = Circuit Operating Work Index 9 The Standard Bond Circuit Coarse Ore Bins Fine Ore Bins Screen Crushing Screen Classification Rod Mill Ball Mill THIS IS THE REFERENCE BASIS FOR ALL WORK
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 ( m), and F80 is the 80% passing size of circuit feed ( m). 2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal
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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
work index covering grinding of fine particles is labelled M. ib (Morrell, 2008). M. ia. values are provided as a standard output from a SMC Test (Morrell, 2004. a) 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. ih
Bond’s approach consists of determining the ore hardness characteristics, or Work Index (Wi) via standardized laboratory testwork. The full suite of Bond comminution tests provide the Ball Mill Work Index (BWi), the Rod Mill Work Index (RWi), the Crusher Work Index (CWi) and the Abrasion Index (Ai)
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