### Bond formula for the grinding balls size calculation

2017-10-19 The grinding balls diameter determined by the Bond formula has a recommendatory character and serves as a starting point for calculating the necessary proportion grinding media feeding a new mill. More precisely adjust the ball load in the mill

More### Bond Work Index - an overview ScienceDirect Topics

The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index. For grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill (see Figure 3.10), a question arises as to whether this practice will alter the ball mill work index (BW i) of the material ...

More### Calculation of energy required for grinding in a ball mill ...

1989-1-1 The Bond work index, W i, as an indicator of the grindability of raw materials is not a material constant but rather it changes with change of size of the grinding product.Therefore, in practice we can expect some difficulties and errors when the energy consumption is determined according to this formula in the case when, for a given size of grinding product, the value of the work index W i ...

More### Correction of Bond Ball Mill Work Index Test for Closing ...

2018-12-7 This is because work index frequently changes as a function of the product size in comminution. If target grind size during a project is changed, or if the test is run at the wrong product size, then it is necessarily to provide a correction. The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis

More### Ball Mill Design/Power Calculation

2015-6-19 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 maximum and finally the type of circuit open/closed ...

More### 20150505 Bond Efficiency-GMG-ICE-v1-r04 Determining

2020-9-24 WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index (kWh/t) WioACT Actual Operating Bond Work Index determined from measurements on the circuit (kWh/t) ... (equation 1). Auxiliary equipment power is excluded. P W = ––– (1) T Where, W is the specific work input (kWh/t), P is the equip- ...

More### USING THE SMC TEST® TO PREDICT COMMINUTION

2020-3-24 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. 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 ...

More### Energy Use of Fine Grinding in Mineral Processing ...

2013-12-18 For P80s finer than 75 μm, the Levin test, a modified Bond ball mill work index test, may be used to predict grinding performance. Signature Plots. No general work index formula governing energy use over a range of conditions, like the Bond equation for intermediate grinding, has yet been found for the fine grinding regime.

More### Calculation of energy required for grinding in a ball mill ...

1989-1-1 The Bond work index, W i, as an indicator of the grindability of raw materials is not a material constant but rather it changes with change of size of the grinding product.Therefore, in practice we can expect some difficulties and errors when the energy consumption is determined according to this formula in the case when, for a given size of grinding product, the value of the work index W i ...

More### Relationships between comminution J energy and

2015-4-16 Table I shows the Bond ball mill work index obtained for the ore samples as well as the iron and silica content in concentrate and tail after LIMS. The concentrate weight recovery was in the order of 50–60%. Furthermore it may be observed that the Bond ball mill work indices for the ore (Wi) varies from 14.6 to 20.9 kWh/t.

More### MODELING THE SPECIFIC GRINDING ENERGY AND BALL

2021-2-24 21 CONCLUSIONS Continued In the present work, equations were also derived, giving: zthe ball-mill power drawP as a function of its dimensions: internal mill diameter D and length L, zthe ball-mill power drawP as a function of the feed D f (mm) and the product size d (mm), the Bond work index w i (kWh/short ton) and the mill throughput T (short ton/h), zthe ball-mill dimensions (D and L), when ...

More### GMSG GUIDELINE: DETERMINING THE BOND

2018-2-20 rod mill Work Index test for these purposes. Chose a o closing screen for the ball mill test one (standard square root of 2 series) mesh size coarser than the plant ball mill circuit P80. If between standard mesh sizes, the finer of the chose two. Results of Bond ball mill tests conducted with closing

More### USING THE SMC TEST® TO PREDICT COMMINUTION

2020-3-24 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. 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 ...

More### Ball Mill Design/Power Calculation

2016-12-12 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 ...

More### CORRELATION BETWEEN BOND WORK INDEX AND

2014-6-27 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 80% passing 100 µm. If the breakage

More### Energy Use of Fine Grinding in Mineral Processing ...

2013-12-18 For P80s finer than 75 μm, the Levin test, a modified Bond ball mill work index test, may be used to predict grinding performance. Signature Plots. No general work index formula governing energy use over a range of conditions, like the Bond equation for intermediate grinding, has yet been found for the fine grinding regime.

More### Ball Mill - an overview ScienceDirect Topics

Ball mills tumble iron or steel balls with the ore. The balls are initially 5–10 cm diameter but gradually wear away as grinding of the ore proceeds. The feed to ball mills (dry basis) is typically 75 vol.-% ore and 25% steel. The ball mill is operated in closed circuit with a particle-size measurement device and size-control cyclones.

More### Relationships between comminution J energy and

2015-4-16 Table I shows the Bond ball mill work index obtained for the ore samples as well as the iron and silica content in concentrate and tail after LIMS. The concentrate weight recovery was in the order of 50–60%. Furthermore it may be observed that the Bond ball mill work indices for the ore (Wi) varies from 14.6 to 20.9 kWh/t.

More### USING THE SMC TEST® TO PREDICT COMMINUTION

2020-3-24 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. 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 ...

More### CORRELATION BETWEEN BOND WORK INDEX AND

2014-6-27 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 80% passing 100 µm. If the breakage

More### Ball Mill Design/Power Calculation

2016-12-12 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 ...

More### Energy Use of Fine Grinding in Mineral Processing ...

2013-12-18 For P80s finer than 75 μm, the Levin test, a modified Bond ball mill work index test, may be used to predict grinding performance. Signature Plots. No general work index formula governing energy use over a range of conditions, like the Bond equation for intermediate grinding, has yet been found for the fine grinding regime.

More### Ball Mill - an overview ScienceDirect Topics

Ball mills tumble iron or steel balls with the ore. The balls are initially 5–10 cm diameter but gradually wear away as grinding of the ore proceeds. The feed to ball mills (dry basis) is typically 75 vol.-% ore and 25% steel. The ball mill is operated in closed circuit with a particle-size measurement device and size-control cyclones.

More### SMC Test® Minerals Processing Comminution Testing -

2021-11-3 SMC Data Processing. The results from conducting the SMC Test® are used to determine the drop-weight index (DWi) which is a measure of the strength of the rock as well as the comminution indices Mia, Mih and Mic. In conjunction with the Bond ball mill work index they can be used to accurately predict the overall specific energy requirements of ...

More### A New Approach to the Calculation of Work Index and

2013-12-24 The mill dimensions, (D × L), are 0.204 × 0.158 m and it is loaded with 6.5 kg steel balls between 25 and 32 mm in diameter. The mill rotates on rolls and its frequency is set to 70 RPM (1.667 Hertz) corresponding to 85% of the critical frequency. The mill power is P = 16.2 Watts, calculated by the formula provided by Stamboltzis [7]. PMN

More### A BASIC UNDERSTANDING OF THE MECHANICS OF

2003-10-15 on wear is another issue. Stresses from Hertzian pressure in 4-high cold mill back up rolls were measured years ago, the results were never published, but of high interest - also, maybe later. K. H. Schröder July 2003 K. H. Schröder: A BASIC UNDERSTANDING OF THE MECHANICS OF ROLLING MILL ROLLS File: SCHROEDER_ROLLS_010703.DOC

More### AMIT 135: Lesson 3 Particle Size Distribution – Mining ...

Gates-Gaudin-Schumann Model. [image: (135-3-1)] The GGS model predicts the cumulative percent passing distribution: Y= cumulative percent passing. x= particle size. k= size parameter. m =distribution parameter. The values of k and m can be determined by linear regression: log y = m log x + k.

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