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. It can be performed at mesh sizes ranging ...Web
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The Rod mill work index is one type of a Bond work index, applicable to the size range of rod milling (very roughly, 12 mm to 1 mm). The Low-energy Impact Crushing work index is another Bond work ...Web
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world. It shows that the ball mill work index is normally distributed with an average of 14.6 and a median of 14.8 kWh/t. bOnd rOd mill GrindAbility The Bond Rod Mill Grindability Test is performed similarly to the ball mill test. The feed sample is stage-crushed to ½" and the test is run under a circulating load. As inWeb
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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 …Web
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The Frederick C. Bond has several grinding indices (ball, rod, abrasion), one of which has been a significant guide for ball mills. The Bond ball mill work index is an expression of the material's resistance to ground and a measure of the grinding efficiency. ... that the revolutions required in all the Bond Work index mill tests conducted ...Web
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As the top feed size for Bond ball mill test is 3.35 mm while for Bond rod mill it is 12.7 mm, Bond rod mill is preferred in this study as more particles in coarse size can be tested. The Bond rod mill tests were conducted consistently with a closing screen of 1.18 mm aperture. The Bond Work indices were used to assess the pre-weakening …Web
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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 models expect a mill with a "wave liner", and is not compatible with mills using "smooth liners". Most laboratories outside of Australia use the wave liner style of machine – these ...Web
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• WiBM – The Bond ball mill work index, in metric units. • WiRM – The Bond rod mill work index, in metric units. • WiC – The Bond impact crushing work index, in metric units. • Density – The coarse particle density measured in either the Bond impact crushing work index test or the drop weight test, t/m³.Web
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Work index is the relation between the SEC and the amount of breakage in an ore. The most common form of this relationship is given as Equation 1, and is often referred to as …Web
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Rod mill power is dependent on mill capacity and work index. Mill power increases with: Increasing rod charge; ... Bond quantified the rod mill power draw as a function of the Work Index, capacity, and a series of correction factors: PM = …Web
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In the paper proposed by García et al. [5], a deep study on the Bond ball-mill and Bond rod-mill standard tests is shown with different ores. The most impacting result of this work is the ...Web
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The Bond rod mill work index ( Wir) is measured using Bond´s standard rod mill grindability test, which is conducted in locked-cycle mode to emulate the continuous closed-circuit operation. Besides the labor-intensive conduct of the test, which typically requires from 5 to 10 cycles for reaching steady-state, it normally requires 8–20 kg of ...Web
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It is a well-known fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. In this study, a variability bysis is carried out with the Bond standard grindability tests on different critical metal ores (W, Ta), ranging from coarse grinding (rod mills) to fine grinding (ball mills). The relationship between wi and grinding …Web
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Using the Bond work index to measure operating comminution efficiency ... "Selection of rod mills, ball mills, pebble mills, and regrind mills," in Design and Installation of Comminution Circuits, Andrew L. Mular and Gerald V. Jergensen, eds., SME, Chapter 23, pp. 393–438.Web
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However, Bond Work Indeces are related to the type of equipment to be used (rod mill, ball mill, SAG uses Drop Ball parameter-Kwhr/m3-, so it is more complex than just specific energy consumption ...Web
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FIGURE 5: BOND ROD MILL WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS (MPa) 5 10 15 20 25 30 35 WiRM (metric) The lack of fit observed relating the crushing Work Index was expected to carry over to the other Bond Work Indices. Figure 5 displays the plot of rod mill Work Index (Wi RM) versus UCS. …Web
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The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined media and ore charge. ... 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 ...Web
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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 …Web
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To calculate the Bond work index ( Wi) in a standard laboratory scale rod-mill, Bond derived the following equation: (1) 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 ...Web
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Chongbo and Bingchen (1992) developed a new method of simulating the calculation of the Bond rod mill work index by using the nth order grinding kinetic test data of the feed. Five kinds of ores (Fe ores, Pb-Zn ore, Au ore, Mn ore) were investigated during the research. In this way the Bond rod mill work indices of any size of product can be ...Web
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The standard Bond method is a tedious time consuming procedure requiring at least 7 - 10 grinding cycles, so that many researchers have tried to simplify this method to be able to perform a rapid ...Web
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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 ...Web
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WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index (kWh/t) WioACT Actual Operating Bond Work Index determined from measurements on the circuit (kWh/t) WiRM Bond Rod Mill Test Work Index (kWh/t) WiSTD Standard Circuit Bond Work Index (expected or designed) used for circuit design. Specific energy …Web
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A Non-standard rod mill result can be converted to a Bond rod mill work index by: Bond Wi RM = 0.49 × (Wi nonstandard)^1.17 Source: Dec 2021 Public Grindability Database Bond rod mill Wi versus A×b for copper …Web
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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 …Web
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This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Work Index of minus six …Web
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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 eachWeb
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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: 1. mill inside diameter of 12 …
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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.Web
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Bond rod mill work index 19.0 kWh/t . Fraction of crit. speed 0.72 . Bond ball mill work index 17.1 kWh/t . Ball volume (nominal design) 12 % Total filling (nominal design) 25 % Crusher Circuit .Web
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Bond Rod Mill Grindability: requires 25 kg of minus ½ in. material: $950. This test determines the Bond Rod Mill Work Index, which can be used with Bond's Third Theory of Comminution to calculate net power requirements of sizing rod mills. The test is a closed-circuit, dry grindability test, is run in a standard rod mill, and can be ...Web
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1. Calculate the Actual Operating Bond Work Index of the grinding circuit. • Estimate the F80 and P80. • Calculate the work or specific energy input from the size reduction …Web
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The tests that fall in the same size range as SPI & SGI are the Bond rod mill work index test and the two Drop Weight Tests (combining JK DWT and SMC Test™). ... 0.92 for the rod mill work index ...Web
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The Bond crushing work index test (sometimes called the "impact work index" test) is noisy, and the difference you observed is perfectly reasonable. The paper by Angove & Dunne (1997) reports a standard deviation in crushing …Web
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3.4.7. Bond rod mill standard testStandard conditions for determining the work index of rod mills under laboratory conditions are: mill size = 305 mm (internal diameter) × 610 mm (internal length) with wave type lining ... Bond had used short tons to determine work index. To convert to metric tons the factor 1.1 has been used here, (62 × 1.1 ...Web
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A Bond rod mill work index test (BRMWI) is a standard test for determining the rod mill work index of an ore sample [21]. The BRMWI is a measure of the …Web
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The Bond rod mill grindability test is a widely used tool to estimate the response of ores to rod milling. However, the mass of ore required to conduct the test, which can typically vary from about 8 to as much as 20 kg, may represent a challenge when sample availability is critical.The present work proposes an alternative procedure, which …Web
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