Fig. 2(a-d) shows the ball mills used in the determination of the Work Index (standard mill BBM and non-standard mills BM-1 to BM-3, all ball mills without lifters). Bond standard ball mill (Fig 2(a); BBM) has a total volume of 22284 cm 3, is fed with 700 cm of ore and 1638 cm of steel balls. This

In Grinding, selecting (calculate) the correct or optimum ball size that allows for the best and optimum/ideal or target grind size to be achieved by your ball mill is an important thing for a Mineral Processing Engineer AKA Metallurgist to do. Often, the ball used in ball mills is oversize "just in case". Well, this safety factor can cost you much in …

Assuming that the standard feed is provided, this study presents a way for estimating the Bond ball mill work index for various specific gravity grinding media (such as steel ball, ceramic ball, steel ball …

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 ...

particle size are calculated and the Bond ball work index is then calculated using the standard Bond ball work index formula: 𝑊𝑖= 44.5 𝑃0.23·𝑔𝑏𝑝0.82·[10 √𝑃80 · 10 √𝐹80] [2] where W i represents the Bond ball work index, F 80 and P 80 …

Ball Mill Wio, BWio 8.6 Circuit Wio, OWio 14.6 Bond Ball Mill Work Index, BWi, kWh/t 13.4 Bond Rod Mill Work Index, RWi, kWh/t 18.1 Table 1. Example of AG/SAG Ball Mill Circuit Wio Calculations [1] [2] ABstrAct Optimum use of power in grinding, both in terms of grinding efficiency and use of installed capital, can have a large effect on ...

Barry A. Wills, James A. Finch FRSC, FCIM, P.Eng., in Wills' Mineral Processing ... The SAG mill product is then crushed to passing 3.35 mm and is subjected to a standard Bond ball mill work index ... This can be calculated using Bond's Equation (3.5). The Bond work index of the unknown ore can then be estimated from the equality given ...

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 tonnage capacity DTPH, operating % solids or pulp density, feed size as F80 and maximum 'chunk size', product size as P80 and …

The results showed that using the non-standard mills (between 20 and 35 cm in diameter), the Bond´s model constants (α=0.23; β= 0.82, and γ = 44.5), are …

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 …

Commentary on the apparatus of the Bond rod mill Work Index. by Alex Doll December, 2015 [email protected]. 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 …

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 ...

The work index (Wi) is calculated in a laboratory-scale ball mill with Bond equation. The Bond work index has been widely used in designing full-scale mills but the Bond test is rather complex, lengthy susceptible to procedural errors and this is why attempts have been made to abbreviate and simplify Bond test procedure (Weiss, 1985).

The Bond method of measurement of the grindability of ores in rod mills and ball mills is long and tedious and requires a standard set of grinding conditions; mill size, ball charge, etc. A number of approximate methods have been reported that shorten or approximate …

The work index values apply to ball mills grinding wet in closed circuit. For dry grinding in closed circuit the work input calculated by Bond's basic Third Theory equation should be mul­ tiplied by 1.30 (see example 6.3.1.). ... Fine product factor (to Bond's equation); should the product size, P, be smaller than 70 microns, then the work ...

grams per revolution (Gbp) is the ball mill grindability. The ball mill work index, Wi (kWh/short ton) is calculated from the following equation (Bond 1961):1 The mill should be cleaned by either blowing air into it or wiping the interior with a cloth and or brush. The FC Bond ball mill is now ready for the next sample.

Bond Work index is also related to the filling rate of the mill, and the conventional Bond Work index mill in the steel ball filling rate is 20%. When the ceramic balls as grinding media are in the same 20% filling rate under the experimental calculation of the Bond Work index are much larger than the conventional steel balls after the …

In a review for a ASM publication, Morrell (in Anderson et al., 2014) notes that Bond's contribution and what made his equation so successful is that he combined it with a series of associated laboratory tests for crushers, rod mills, and ball mills that, when applied to practical design situations, provided reasonably life-like responses, i ...

Both procedures are valid only when F100 = 3.35mm. This paper describes a methodology for providing an estimation of the Bond ball mill work index for a sample of non-standard size ∕ −3.35 mm) when all the parameters from Bond's ball mill (F100 = equation using that non-standard feed are known.

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 ...

A fundamental equation for computing the specific energy required for the mill during the comminution process is Bond's equation Wills and Napier ... the Bond ball mill work index was determined ...

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, …

For the ball mill grindability test, the work index is calculated from the following revised equation (in short tons): where: Pi = sieve size tested (microns) Gpb = ball mill grind ability Wi, P & F have the same meanings as in the top equation. Equipment required: Laboratory ball mill, 34.02 cm x 34.02 cm with following ball charge: Agitator ...

bond ball mill work index equation in wills. CORRELATION BETWEEN BOND WORK INDEX AND . 3- STANDARD BOND TESTS The Bond's standard ball mill is used to determine the work index value of differ ent samples. The Bond work index is defined as the kilowatt-hours per short ton required to break from infinite size to a product size of …

the Bond Work Index (kWh/t) can be rapidly estimated (less than 2 hours) and show a high accuracy for mills of non-standard dimensions (R2= 0.96). Keywords: Bond´s Work …

Table 3 shows the comparative values obtained between the standard Bond ball mill and the Nematollahi mill. Menéndez-Aguado et al. [17] examined the possibility of determining the work index in a Denver laboratory batch ball mill (Figure 1) with the same inner diameter as the Bond ball standard mill.

Physicochem Probl Miner Process 53(1): 321-332. 11. Kaya E, Fletcher PC, Thompson P (2002) Reproducibility of bond work index with different standard ball mills. In: Dodge P, Safford AZ (Eds.), Dawson Metallurgical Lab, Inc Salt Lake City, USA. 12. Britvic E, Steadman H, Williams N (2016) A comparison of bond work indices from Sepor and …

The work index Wi can be determined from plant operations and from laboratory ball mill grindability, rod mill grindability, and impact crushing tests. The laboratory test results are used to check the …

This paper examines the determination of the BWI on finer samples and proposes an equation for the determination of the BWI on finer samples. ... A. Jankovic, S. Suthers, T. Wills, W. Valery. Evaluation of dry grinding using HPGR in closed circuit with an airclassifier ... Correction of Bond Ball Mill Work Index Test for Closing Mesh Sizes ...

Over the years, alternative procedures to the Bond grindability test have been proposed aiming to avoid the need for the standard mill or to reduce and simplify the grinding procedure. Some of them use the standard mill, while others are based on a non-standard mill or computation techniques. Therefore, papers targeting to propose a …