Tavares et al. (2012) and Ahmadi et al. (2013) then used this same model and a batch test as an alternative to the standard Bond rod mill test to estimate the Bond rod work index. Grandy and ...
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The Bond Rod Mill index (RWi) is a measure of the resistance of the ore to grinding to a coarse product size. Table 4 shows the RWi for each composite – note that the oxide composite was not competent enough for measurement using the RWi test, and therefore was excluded. Table 4 – Bond Rod Work Index Sample ID Closing
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2.2 Bond Ball/Rod Mill Work Index. Bond ball mill work index (BBMWI) test is a standard test used to measure the ball mill work, which is calculated in accordance …
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Design of Rod Mills. ... Bond Work Index W i (kWh/t) Rod mill, test at 1400 μm (12 mesh) 13.0: Ball mill, test at 212 μm (65 mesh) 11.5: Ball mill, test at 150 μm (100 mesh) 12.2: Between the rod and ball mill an intermediate separator in the form of a hydrocyclone was placed. Determine power at the pinion shaft (including loss due to ...
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The rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing 12.7 ... Ball mill design requires a Bond work index, BWi, for ball mills at …
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Typically R = 8. Rod Mill Charge: Typically 45% of internal volume; 35% – 65% range. Bed porosity typically 40%. Height of bed measured in the same way as ball mills. Bulk …
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Bond Rod Mill Grindability Test. The test determines the Bond Rod Mill Work Index which is used with Bond's Third Theory of Comminution to calculate net power requirements when sizing ball mills*. Various correction factors may have to be applied. The test is a closed-circuit dry grindability test performed in a standard rod mill.
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databases which included JKDWT and Bond rod a nd ball mill work indices (Ma rks et al., 2001). For design of the circuit, the authors use d the FL in-house mill selec tion criteria.
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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 ...
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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 …
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Here is a list presented in table form of Rod Mill Work Index as tested/presented by SME handbook of mineral processing, N.L Weiss Editor, N.Y. 1985. Rapid Determination of Bond Rod-mill Work Index by Craig Taylor on Scribd
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Rod Mills may be considered either fine crushers or coarse grinding equipment. They are capable of taking as large as 2″ feed and making a product as fine as 35-48 mesh. Of particular advantage is their …
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The reason for this variation in ball mill work index is because the ore at Mt. Milligan has an intrinsic exponent of –0.45 in the 100 µm to 200 µm size range, not the –0.50 exponent empirically measured by F. Bond. The work index increase between 100 µm and 76 µm is due to a porphyritic grain size that causes a spike in energy
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Where Wi is the work index, W is the work input (motor output) and F and P are the 80% passing sizes of the feed and product respectively, in micrometers. This relationship between feed and product energies and the calculation by difference of the required grinding energy is the basis for the two Bond Rod and Ball Mill Work Index …
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The Bond rod mill is made of metal, 305 mm maximum inside diameter, with a wave-type lining. The internal mill length is 610 mm. The grinding charge consists of six 31.8 mm …
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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) ... Given that the rod and ball mill test are the most important in circuit design (contributing about 90%–95% of total specific energy consumption in SABC circuit simulations), the ...
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Commentary on the apparatus of the Bond rod mill Work Index by Alex Doll December, 2015 alex.doll@sagmilling 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 …
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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 …
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Typically R = 8. Rod Mill Charge: Typically 45% of internal volume; 35% – 65% range. Bed porosity typically 40%. Height of bed measured in the same way as ball mills. Bulk density of rods = 6.25 tons/m3. In wet grinding, the solids concentration 1s typically 60% – 75% by mass. A rod in situ and a cutaway of a rod mill interior.
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The initial sample volume is 207 cm3 instead of 700 cm3; accordingly, the test can be performed on 3 kg instead of 10 kg. The procedure involves dry grinding in a closed cycle until a 250% circulating load is reached. The Bond work index is …
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standard Bond crushing, and rod mill work indices, abrasion indices and by Dawson for Bond Ball Mill Work Index tests using crushed feed, and Standard Autogenous Grinding Design (SAGDesign) Tests, patented by Outokumpu. (See reference 8 below). The comparison of these results gives context to how the various measurements relate to …
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The specification for the apparatus to determining a "Bond" rod mill work index is first described in Bond & Maxson (1943). It states that the apparatus is a …
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The design of rod and ball mills is still carried out with the Bond ball mill and rod mill grindability tests. As discussed earlier in this paper, it is important in this case to match the reduction size of the test to that desired from the industrial mill. As such, primary ball mills should be designed with the rod mill work index, and single ...
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Where Wi is the work index, W is the work input (motor output) and F and P are the 80% passing sizes of the feed and product respectively, in micrometers. This relationship between feed and product energies and the calculation by difference of the required grinding energy is the basis for the two Bond Rod and Ball Mill Work Index Tests. Both were
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To calculate the Bond work index ( Wi) in a standard laboratory scale rod-mill, Bond derived the following equation: 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 work ...
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2.2 Bond Ball/Rod Mill Work Index. Bond ball mill work index (BBMWI) test is a standard test used to measure the ball mill work, which is calculated in accordance with the procedure proposed by the Bond [21]. The BBMWI determines how much energy is needed to grind a sample of ore in a ball mill [22].
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The specification for the apparatus to determining a "Bond" rod mill work index is first described in Bond & Maxson (1943). It states that the apparatus is a tumbling rod mill to be operated in a locked cycle test at a fixed circulating load. The geometry of the grinding chamber is described as: • mill inside diameter of 12 inches
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The specification for the apparatus to determining a "Bond" rod mill work index is first described in Bond & Maxton (1943). It states that the apparatus is a tumbling rod mill to be operated in a locked cycle test at a fixed circulating load. The geometry of the grinding chamber is described as: mill inside diameter of 12 inches
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See this useful summary Table of Bond Work Index by Minerals. For any circuit, whether a crushing circuit, a rod mill, or a closed ball mill circuit, the Work Index always means the equivalent amount of energy to reduce one ton of the ore from a very large size to 100 um. The sample was received crushed appropriately for the ball mill test.
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The Work Index calculated from the testing can be used in the design and analysis of ball mill circuits. ... GSL can carry out Bond Rod Mill Work Index tests to determine the energy requirements for milling ore in a rod mill. The test requires a minimum of 20kg of -12.5mm material. Closing screen sizes typically range from 4.75mm to 212µm.
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