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.
In this study, samples of bauxite whose chemical composition and Hardgrove Index values are known were ground to micronized size by a laboratory scale stirred media mill and its performance was compared with a laboratory scale ball (Bond) mill. Stirred media mill decreased bauxite d 50 size from 780 to 5 µm in 3 min. But, the ball mill has ...
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…
The Bond ball mill grindability test is one of the most common metrics used in the mining industry for ore hardness measurements. The test is an important part of the Bond work …
When F is the size in microns which 30 per cent of the new ball mill feed passes, P is the microns which 80 per cent of the last cycle sieve undersize product passes, and P1 is the opening in microns of the sieve size tested, then ball mill work index Wi is calculated from the following revised (1960) equation:
Alternative tests soon arose after Bond's proposal to avoid the need for the standard mill and time-consuming procedure. Therefore, papers dealing with this problem are …
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 ...
Based on the standard procedure defined by Bond, the ball mill work index is determined by simulating a closed cycle dry grinding in a laboratory Bond ball mill until a stable circulating load of 250% is established (Bond, 1949, Bond, 1952, Bond, 1961). The ball mill work index is determined by Eq. (10). The recommendation is the ball mill ...
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 …
1.. IntroductionA Bond Ball Mill Work Index test is a standard test for determining the ball mill work index of a sample of ore. It was developed by Fred Bond in 1952 and modified in 1961 (JKMRC CO., 2006).This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating …
The F. Bond ball mill We continue to consider the methods of grinding process planning based on the calculations of different energy indexes. In this article, we are going to consider the methodology for calculating index, which has a direct impact on the choice of SAG mills when engineering the grinding process. ВWi is the ball grinding …
This paper proposes a new method to estimate the Bond Ball mill work index result to decrease experimental time. Four types of ore (limestone, fluorite, chalcopyrite, …
New video: The SMC Test versus the Bond Rod Mill Work Index test. Video discusses how these two tests are similar, how they are different, what to be aware of when building a grindability database ...
Starting from the first-order grinding kinetics defined by means of the Bond ball mill, this paper discusses a simplified procedure for a rapid determination of the …
The inserts for the ball end mills also come in three styles: a general-purpose HTM1 grade for steels up to 50 HRc, a specialized HTM2 grade meant specifically for stainless steels, and HTHM grade for hardened materials from HRc 40 up to HRc 65.Each series has unique geometry and an extremely abrasion-resistant coating for excellent performance.
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 …
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 …
Several modifications or solutions to Bond's mill ball charge specifications have been proposed (Table 1).Mosher and Tague (2001) recognized the difficulty in making up a mill charge corresponding to Bond's specifications and proposed the use of worn balls from batch, pilot or full-scale ball mills that maintain Bond's specifications. Since the …
Differences up to 6,2% in the Bond ball mil work index can be observed due to different siz distribution in P 80 calculation.. 13 ores were tested using the Bond ball mill grindability test, obtaining P 80 using different interpolation functions. Rosin Rammler's model showed the best behavior, so its use must be not only suggested, but …
The Bond ball mill grindability test is one of the most common metrics used in the mining industry for ore hardness measurements. The test is an important part of the Bond work index methodology ...
The purpose of this research was to statistically evaluate comparative Bond Work Index, BWi, determinations using two different commercial ball mill testing apparatus. These experiments were run ...
The Bond Ball Mill Grindability Test is a locked-cycle laboratory grinding test. It provides the Bond Ball Mill Work Index which expresses the resistance of a material to ball milling. This Index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required for grinding, and for ball mill …
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, …
This index is determined on a laboratory-scale using a Bond ball-mill and by simulating dry grinding in a closed circuit until the 250% circulating load has been …
The computation of a Bond ball mill work index was empirically calibrated by Fred Bond using a short ton basis. The modern (metric tonne) basis is the following equation: Derived values composed from Wi BM results. …
feed size distribution is different to a standard Bond ball mill work index test. A series of 10 samples for an Andean copper project were treated to both the SAGDesign (and 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 feed) are given in Table 1.
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 …
This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Work Index of minus six mesh …
Menéndez-Aguado et al. examined the possibility of determining the work index in a Denver laboratory batch ball mill with the same inner diameter as the Bond ball standard mill. The research was …
A Bond Ball Mill, 12" x 12" of fabricated construction comes with electric motor and gear reducer drive, digital counter, jogging button to provide positioning of drum for loading and unloading, emergency stop button, …
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.
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 ib is NOT the Bond ball work index). M ic and M
standard Bond ball mill in time intervals of 0.5 min, 1 min, 2 min, and 4 min. After each grinding run, the mass of the sample is measured, and the PSD is determined.
The grindability of raw material is generally determined by Bond's standard ball mill grindability test (developed by the Allis Chalmers company). 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.
2.2. Ball mills and operation conditions 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
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).
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 …
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.
The ball mill is designed to accept a ball charge in accordance with F. C Bond's standard. This ball charge consists of 286 balls as follows: 44 x 35mm balls; 67 x 30mm balls; 10 x 25.4mm balls, 71 x 19.05mm balls and; 94 x 12.7mm balls; Fully automated version of the Bond Index Ball Mill is also available on request.
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 …
