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The Bond work index most commonly referred to is the BBM work index. This value is obtained in a 12" × 12" laboratory mill running at 70 rpm, with rounded inner edges and without lifters. The grinding charge is comprised of …Web
In the Bond ball mill test, the work index is finally obtained ... two-stages grinding-water-cyclone grinding and classification new process and giant mill were developed, one is rod mill open ...Web
The Pendulum Tester / Bond Impact Crushing Work Index Tester. Working principle Crushing by impact. 76 mm maximum feed size. Test repetition: At least 10, preferably 20 test runs. Adjustable crushing angle Repeatable crushing results Safe two-hand operating buttons The Bond Crushing Work Index (CWI) describes the competency of the ore at …Web
Similar to the ball mill work index, the rod mill work index is a tumbling test that includes both attrition and abrasion breakage …Web
Morrell's methodology (Morrell, 2004a, 2004b, 2008) does not use the Bond work index directly; however, it uses the Bond ball mill test as basis for calcul ation of the energy required to grind ...Web
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
Classification Rod 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 BASISWeb
The basic objective is to achieve a circulating load in a locked-cycle test using a calibrated laboratory rod mill. The work index is then inferred from the feed and product size (FS0, PS0), the classification size, P, and the mass of material finer than P (M) produced per revolution of the mill (R), the Grp: WI I 62 p0.23 .Web
I have to grind a ore sample (1 kg at -6 mesh) to 80% passing 300 microns using a lab rod mill. ... STEEL BALLS IN A MILL AND CLASSIFICATION. A. 1. REPLY. 224. VIEWS. Started by ... I want to determine the size of steel ball, according to the equation of Bond and the equation work index: W=WI* (10/√P80 -10/√F80), for calculating Wi, I need ...Web
The rod mill work index (in kWh/t) is then given by (1) Wir = 68.4 P 1 0.23 Grp 0.625 10 P 80-10 F 80 where Grp is the average of the last three net grams of sieve undersize produced per revolution and F 80 is the 80% passing size in the feed. In the tests P 1 was typically set at 1.18 mm.Web
The mill product can either be finished size ready for processing, or an intermediate size ready for final grinding in a rod mill, ball mill or pebble mill. AG/SAG mills can accomplish the same size reduction work as …Web
An global operational work index, W iog, is defined for a conventional grinding plant consisting of a rod mill followed by three inverse hydrocyclone-ball mill grinding circuits and its value is estimated online. This global operational work index is based on an equivalent unitary ball mill circuit. The foundation for W iog is Bond's equation ...Web
The only thing to be careful of is that the laboratory uses a Bond rod mill with a wave-type liner. There are laboratories who claim to have a "rod mill work index" apparatus, but they use a smooth liner which is wrong and Bond's equations are not calibrated to …Web
Abstract An global operational work index, W iog, is defined for a conventional grinding plant consisting of a rod mill followed by three inverse …Web
In the determination of ball mill work index 15 kg of representative ore at ... 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. ... The effect of screen versus cyclone classification on ...Web
Rod mill grindability tests for Work Index are run at 10 or 14 mesh, and ball mill Work Index tests are run at the desired grind if finer than 28 mesh. All the data obtained is evaluated and one or more of the following recommendations made: ... it is to be expected that the cost of dry classification would be higher than for wet classification.Web
The middle size class, represented by rod milling, is fitted to a tumbling test, referred to as the Bond rod mill work index (WiRM, or RWi). The apparatus used to …Web
Classification Rod 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 …Web
A "raw" work index is an uncorrected work index computed using Eq. (10) based on laboratory results using a non-standard feed (not the −3.35 mm feed prescribed by Bond). A "raw" work index is used in the correction procedure to predict a "corrected" work index that is adjusted to mimic a standard feed.Web
Technical Information. Information about sample size, calibration, precision and accuracy. The SMC Test® is the most widely-used comminution test in the world for AG & SAG Mills, HPGRs and Crushers. The SMC Test® was developed to provide a range of useful comminution parameters through highly controlled breakage of rock samples.Web
The FC Bond Work Index Test Ball Mill was designed by F. C. Bond for use in determining the Bond Index, a measure of grindability and power required for grinding applications. The FC Bond Mills are used in laboratories throughout the world. A copy of Fred C. Bond's Method of Crushing and Grinding for determination of the Bond Index is included with …Web
Generally Bond work index for mill dimensioning and controlling is measured by grinding a feed material of less than 3.36 mm (− 6 mesh) particle size under standardized conditions in a Bond's mill (Diameter × Length = 305 mm × 305 mm). Bond's method simulates closed-circuit grinding which is carried out in sections until the …Web
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.Web
The Bond work index most commonly referred to is the BBM work index. This value is obtained in a 12" 12" laboratory mill running at 70 rpm, with rounded inner …Web
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 performed at sizes ranging from 4.76 mm to 210 microns.Web
You also need a rod mill work index to design a ball mill operating on a coarse feed, above about 4 mm. Q1: You design for a typical percentage of critical speed, usually 75% of critical. Then you iterate the mill diameter using a Morrell C-model or equation to get the RPM that corresponds to 75% for that mill diameter.Web
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
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).Web
The rod mill feeds a wet ball mill at a feed size of 1.0 mm (1000 μm) and produces a product with 80% passing a 150 μm screen. The rod mill is in an open grinding circuit. Determine: 1. the shaft power of the rod mill, 2. the size of the industrial mill. Data: Laboratory Standard Bond Test: Rod Mill: Grindability index at 10 mesh = 13.5 kWh/t ...Web
Avg RW Index: Rod Mill kWh/t: Rod Mill Range: Rod Mill No.tests: Alumina: 12.2: 9-17: 3: Andesite: Barite: 5.7: 2-12: 6: Basalt: Bauxite: 10.8: 2-20: 33: Cement …Web
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 …
They evaluated different rock mechanical tests including UCS test, PLS test, BTS test, hardness test, and grindability test methods such as Bond ball mill work …Web
To calculate the Bond work index (W i) 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 …Web
Further Bond tests showed that the work indices of standard crushed −3.35 mm and −2.36 mm feed were similar (15.0 and 15.3 kW h/t, respectively), while the HPGR crushed −2.36 mm feed produced a lower work index of 14.0 kW h/t. These results agree with observations by other workers that HPGR renders a sample more amenable to …Web
The test enables basic grinding power requirement in ball mills to be determined, from the feed 80% passing size (F80) to circuit 80% passing size (P80), using the classic Bond formula. The rod mill work index test requires 20 kg of material, which is crushed to -12.7 mm (1/2) and tested in a standard Bond Rod mill.Web
In this instance, 50 mm top size would suffice. If there is a pebble crusher in operation and the rod mill work index is fairly high (>20 kWh/t) you might want to increase the makeup size to 65 mm, depending on the final product size you are looking for …Web
2.2 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 …Web
