The Bond rod-mill work index is used in conjunction with Bond's third theory of comminution to merely calculate net energy requirements for sizing rod-mills. This test was originally developed in the mid 1930s by F.C. Bond. Though, it was altered in succeeding years, it has essentially remained unchanged since 1961 [1]. ...
The work index covering grinding in tumbling mills of coarse sizes is labelled M. ia. The 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 ...
Bond's work index is one of the mostly widely used metrics of mineral grindability. In spite of its ubiquity, users are often not aware of the nuances of the work index family: what are its...
A standard Bond mill (Fig. 1) was designed to perform the work index tests and determine the energy consumption of various s minerals.The mill has a round internal housing at the corners, has no lifters, and is for dry grinding. The inner diameter and the length are 0.305 m, and the ball load is 19.4% of mill volume (equaling a total weight of …
This is or was used by to acquire the Impact (AKA Crushing) Work Index for sizing crushers. Use this in complement to the Bond Crushing Work Index Procedure. Another Summary Table of various Impact Work Index by Rock or Mineral Type (/metric tonne). Find a referential Rod Mill Work Index Table here.
Section snippets Material and experimental Bond tests. Samples of dacite and basalt from Serbia, copper ore from a South American meta-sedimentary copper mine, and copper porphyry ore from Canada, of different feed sizes, were used to determine the Bond ball mill work index according to the standard procedure.A standard Bond laboratory …
An analysis of the results shows a direct relationship between the Bond work index and the Denver work index when the Bond test is defined adequately to the …
In the latter case, correction factors needed for reasonably accurate scale-up to industrial size mills under various design conditions may be factored out of the basic Bond Operating Work Index, to derive …
FIGURE 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 …
Here is the old Allis-Chalmers Bond Work Index Grindability Test Procedure. The standard feed is prepared by stage crushing to all passing a 6 mesh sieve, but finer feed can be used when necessary. ... then ball mill work index Wi is calculated from the following revised (1960) equation: The average value of P at 100 mesh is 114 …
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 …
The Bond ball mill grindability test is run in a laboratory until a circulating load of 250% is developed. It provides the Bond Ball Mill Work Index which expresses the resistance of material to ball milling. This happens after 7-10 grinding cycles, which shows that the procedure is a lengthy and complex one and is therefore susceptible to procedural errors.
The work index covering grinding in tumbling mills of coarse sizes is labelled M ia. The work index covering grinding of fine particles is labelled M ib. M ia values are provided as a standard output from a SMC Test® (Morrell, 2004a) whilst M ib values can be determined using the data generated by a conventional Bond ball mill work index test (M
The Bond work index is one of the most useful and interesting parameters used in designing grinding equipment. However, it must be obtained under restrained conditions, especially in regards to the Bond standard lab mill. The main objective of this study is to show how this index can be obtained using a Denver ball mill, which is …
This paper describes a methodology for providing an estimation of the Bond ball mill work index for a sample of non-standard size (F 100 ≠ −3.35 mm) when all the …
Understanding your ore's variation of work index by size is particularly useful for SAG mill troubleshooting and production forecasting. Examples of the variation in work index at …
It provides the Bond Ball Mill Work Index which expresses the resistance of material to ball milling. This happens after 7–10 grinding cycles, which shows that the procedure is a lengthy and ...
The Work Index is used when determining the size of the mill and grinding power required to produce the required ore throughput in a ball mill. 2. Procedure 2.1. Bond Ball Mill Grindability The sample was crushed to passing 6 mesh (3.35mm), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
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
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 …
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. The samples were characterized as hard ...
The basic work index equation is: W = 10 Wi/√P – 10 Wi/√F(1) where W is the work input required in kilowatt hours per short ton to grind from 80% passing F microns to 80% passing P microns, and Wi is the work index, or the grinding resistance parameter. It represents the energy input required in kilowatt hours to reduce a s…
The ball mill grindability test is used for describing ore hardness and it is so widespread that the Bond Work Index generated from the test is often referred to as an ore characteristic. The ore resistance to grinding and energy consumption can be expressed using the work index and Bond's Third Theory.
The test determines the Bond Impact Work Index which is used with Bond's Third Theory of Comminution to calculate net power requirements when sizing crushers*. It is also used to determine the required open-side settings (jaw crushers and gyratory crushers) or closed-side settings (cone crushers) for a given product size.P80 = 25400 x …
A) Total Apparent Volumetric Charge Filling – including balls and excess slurry on top of the ball charge, plus the interstitial voids in between the balls – expressed as a percentage of the net internal mill volume (inside liners). B) Overflow Discharge Mills operating at low ball fillings – slurry may accumulate on top of the ball charge; causing, …
To calculate Bond rod-mill work indices, the four samples were screened and the particle size distributions plotted in Fig. 2.The plot was used to find F 80 of the samples for calculations. Fig. 3, Fig. 4 show the grinding kinetics of Pb, Cu, Fe, and Mn ores in the Bond rod-mill in different test-sieves. The slopes of all lines in the figures are equal to …
For comparing the standard Bond rod-mill work index and the new modeled method, work index (Wi) and produced fine particles in a cycle (Gi) for the four samples determined. The performed paired Student's t-test results indicated that the Standard Deviation for Gi and Wi obtained by the shortened method are respectively 0.50 and 0.58 in ...
The Bond ball mill work index test is a standard procedure to determine the ore grindability in function of specific energy (kWh/ton). This index is extensively used in the mineral processing industry and needs an available skilled staff and specially prepared feed samples (Aksani and Sönmez, 2000).
The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value constitutes ore characteristic and is used for industrial comminution plants designing. Determining the Bond work index value is quite complicated, timeconsuming and requires trained operating personnel and …
In this paper, a new method based on the Population Balance Model (PBM) is proposed and validated to estimate the results of the Bond ball mill work index test (Wi …