Kinetic grinding test approach to estimate the ball mill work index
The Bond work index (BWI) is a well-known method used when selecting comminution equipment, to evaluate the grinding efficiency and to calculate the required grinding power.

The Bond work index (BWI) is a well-known method used when selecting comminution equipment, to evaluate the grinding efficiency and to calculate the required grinding power.
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 …
Therefore, its foundation can be a concrete floor slab designed for dead load only, whereas a cylindrical ball mill requires a reinforced concrete submat with a minimum of two times the mass of the …
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.
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, …
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 …
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 …
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 …
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 …
This 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 …
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.
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
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 Tovarov grindability index is used to determine the influence of materials on the cement clinker grinding capacity of a mill; the basis is rotary kiln clinker with a defined grindability index of a = 1.According to this, a mill grinding 30 t/h clinker, will grind 30 x 1.40 = 42 t/h of marl or 30 x 0.6 = 18 t/h of silica sand. The grindability index of rotary kiln …
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 …
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.
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 …
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 …
The goal of this work is to create an equation to adjust a Bond ball mill work index from one P80 basis to another. The proposed model consists of two components, the variable coefficient that is ...
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 Source 5 Source 6 Source 6 KWh/t Source 6; Avg Bond Work Index: kWh/t: kWh/t: kWh/sh.t: kWh/t: kWh/t: kWh/t: kWh/t: …
Wells-Index mills have a completely different milling head design than any other milling machine in the world. Most heads are based on a Bridgeport design and have been cloned by Taiwanese and Chinese manufacturers. The Wells-Index milling head is a much more robust and durable design for heavy cutting with most components such as the spindle ...
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 …
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, such as the Denver lab ball mill, to determine work index. Results obtained show that with an adequate adaptation of the. methodology, especially using a volume correction factor, the.
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 …
The work index equation for a ball mill test was generated by Fred Bond to empirically predict the operating work index of an industrial ball mill (8 ft dia by 8 ft effective grinding length ...
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...
The 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.
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 Bond ball mill work index is one of the most commonly used grindability tests in mining, and is often referred to as the Bond work index. The test is a 'locked-cycle' test where ground product is removed from …