The Thirty-nine samples were submitted for the Crusher Index (Ci), SAG Power Index (SPI®), Standard Bond Ball Mill Work Index (BWI) and Modified Bond Ball Mill work Index (MBI) tests. The Ci, SPI® and Bond Wi values of these samples show a good indication of ore hardness variability within the ore body.
Detailsresults using sound engineering principles, that allow definitive energy requirements for SAG and Ball Mills to be picked, and fourth, the assignment of mill dimensions required to draw required power. ... • Bond Rod Mill Work Index Test • Bond Ball Mill Work Index Test • Bond Abrasion Test (High speed vanes) • MacPherson …
DetailsTransfer Size, T80: Is the 80% passing size of ore as it passes from the SAG mill to the ball mill. It is typically about 1/3 the size of the screen opening but can be coarser than 1/3, especially when a pebble crusher is used. Screening at 5 mm ensures that the T80 will be about 10 mesh (1.7 mm) ensuring that the ball mill will work efficiently.
DetailsA screen analysis down to 3 mesh is also made. Bond Impact, grindability tests, and abrasion index tests are also run on the sample. 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.
DetailsCommentary 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 …
DetailsIn those days, 3 stages of crushing, and rod and ball mill grinding, were common in comminution flowsheets. Bond's Rod Mill Work Index (RM Wi) and Ball Mill Work Index (BM Wi) tests provided good designs for grinding mills. If the design was 1200 t/d, each stage had to be able to produce 1200 t/d or (54 t/h at 92.6% availability).
Detailsincludes a Bond Ball Mill Work Index test on SAG ground ore from the first stage of the test. The ratio of SAG pinion energy to Bond BM Wi is a key parameter in a SAG mill grinding circuit design, because this ratio controls the power split between SAG and ball mills at the target T80 transfer size( ). INTRODUCTION
DetailsAnalysis of Bond Work Index test results for crushing, rod milling and ball milling will indicate uniformity or otherwise of breakage characteristics in different size ranges. Very often one is much higher (or lower) than the others and such variations can govern the power distribution between primary and secondary stages of grinding.
DetailsThe ball mill oversize feed factor (EF 4 BM) is always calculated with the rod mill work index for the optimum feed size and the ball mill work index for EF 4 BM. The model assumes that the calculated value of E ssbm + the specified contingency is greater than the sum of E sag + E peb ; otherwise E bm will be negative.
Detailsdifferent grinding media of ball mills, rod mills and SAG mills. Crushing ratio Comparison. The biggest feature of SAG mills is the large crushing ratio, which can crush and grind the materials to 0.074mm at one time, accounting for more than 20% to 40% of the total product.
DetailsMay has shown that the SAG/Bond Wi Ratio, that is, the SAG mill hardness (kWh/t to grind the ore from F80 152 mm to T80 1.7 mm) divided by the Bond Ball Mill Work Index (also in kWh/t) for any ore, is a key property that should be used in the design of a SAG/ball mill grinding ... Note that all of Fred Bond's work dealt with rod and ball …
Detailsreduction ratio forms the X axis (empirically calibrated to be F 80 0.2/P 80 ... from a laboratory HPGR or SAG mill instead of stage crushing), then the regression equation can be used to predict ... Sd_bwi) test and the standard Bond ball mill work index test with 180 µm closing screens. The SAGDesign results (with the non-standard ball mill ...
Detailsoperating work index) is also presented a product of for each simulation. For Greenfield design of an AG/SAG-ball mill circuit with JKSimMet, the additional power requirement in the ball mill(s) is determined with the Bond ball mill work index and the phantom cyclone technique. COMMINUTION Trusted Bench Scale and Pilot Scale
DetailsRod mill work index is used in the SAGMILLING Bond/Barratt specific energy consumption model. The work index is used to calculate the energy requirement to grind …
DetailsThis 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 Index …
Detailsworld. 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 in
Detailsfoundation of ball mill . Bond Ball Mill Work Index in kWh/t, and the ratio of SAG kWh/t to BWi. ... Our SAG/AG ball and rod mills ... Manual design of SAG/ball/rod mill foundations ...
DetailsDatabase for all tests done to date for SAG Pinion Energy (to T80 1.7 mm) and Bond Work Index on SAG ground ore. To data 63 SAGDesign tests have been done and this allowed the Tenke ... Bond rod and ball mill work indices are readily converted to pinion energy for rod and ball mills but not for SAG mills. Reproducibility, while not …
Detailshave similar ratios in the resistance to abrasion, attrition and crushing. A completely different rock type (eg. Tertiary andesite) will have a completely different set of ratios, and therefore will likely require a ... Grindability Database is plotted as rod mill work index (Bond in blue, non-standard in red) versus the A×b of a drop weight ...
DetailsCommon convention generally refers to high-aspect ratio mills as SAG mills (with diameter to effective grinding length ratios of 3:1 to 1:1), low-aspect ratio mills (generally, a mill with a significantly …
DetailsRoM Ball mills, like SAG mills, utilise coarse rocks in the RoM feed as grinding media but with 25 – 40% steel balls added, which is advantageous when the coarse fraction in the RoM feed is ...
Detailswhere: WiC is the Bond crushing work index, unitless P80 is the SAG hydrocyclone overflow 80% passing size, µm F80 is the milling circuit feed 80% passing size, µm, WiRM is the Bond rod mill work index, unitless WiBM is the Bond ball mill work index, unitless EF4 and EF5 are the Rowland efficiency factors for oversized feed and fine grinding.
DetailsThe relationship between the Bond rod mill work index and Bond ball mill work index tells a lot about the difference in grindability, and hence energy requirements, between …
DetailsThe 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.
DetailsIII-181 0 5 10 15 20 25 Number 0-2 2-3 3-4 4-5 5-6 6+ Mill diameter (m) Figure 1: Ball mill diameters used for power draw analysis 0 400 0 800 1200 0 400 800 1200
Detailscan 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. values are also provided as a standard output from a SMC Test ® (Morrell, 2009). The general size reduction equation is as follows (Morrell, 2004. b): f x f x 2. 1 i i. 4 2 W M x x. 1 (1) where ...
Detailsthe mill. Fred Bond had based the majority of his work on ball mill feed which in his day was rod mill discharge. Since rod mill discharge usually is about 80% passing 10 mesh, it can rightly be concluded that the Bond ball mill work index equations relate to the comminution of this size of product. Mistakes in SAG power requirement …
Details2.2 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].
DetailsFIGURE 8: ROD MILL/BALL MILL WORK INDEX RATIO v. UNCONFINED COMPRESSIVE STRENGTH 100 200 300 400 UCS (MPa) 0 0.5 1 1.5 2 WiRM/WiBM (metric) Siddall et al (1996) identified the ratio of Bond rod mill Work Index and ball mill Work Index as being indicative of an ore's compentency. Figure 8 plots this ratio versus …
DetailsA linkedin group was recently discussing this by asking: I've tried to estimate AG/SAG Mill power requirements using several different methods: (1) Using the results of SMC data (2) Using SAG Power Index (SPI) data (3) Using the 1989 Barratt method updated on Alex Doll's Web site (February 16, 2015) (3) Using Don Burgess' …
Detailsmill. As such, primary ball mills should be designed with the rod mill work index, and single-stage ball mills should be with both the rod mill and ball mill indices. This is because it is common to observe a difference (sometimes significant) between the rod mill and ball mill index values for a given ore type (McKen, Verret, & Williams, 2006). On
DetailsPE series jaw crusher is usually used as primary crusher in quarry production lines, mineral ore crushing plants and powder making plants.
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