bond work index calculation mill efficiency

Accurate Scale Up - IsaMill™ Advantages | Isamill

Additionally while techniques like the Bond Work Index and "scale up factors" are useful for coarse grinding, they can significantly underestimate grinding needs below 100 microns. Similarly Tower Mill laboratory tests typically use much finer media than can be used in full scale operation and testwork is done in "batch" mode.

Testwork: Bond ball mill work index - SAGMILLING.COM

Testwork: Bond Ball Mill Work Index. 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 test cycles and replaced by fresh feed. The test much achieve a steady-state before completion.

A New Approach to the Calculation of Work Index and the ...

The mill power is = 22.5 Watts, calculated by (6). Fi- P nally the product is wet screened to find the size d80. 2.4. Rod Mill Semi Continuous Process The same mill is used for the semi continuous grinding tests which is similar to the Bond test but with the exist- ing mill of known power. After time the mill product is t

Bond Work Index Procedure and Method

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 a standard ball charge.. Below describes in general terms the Bond Work Index Procedure used by a Professional Metallurgical Testing Laboratory.

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Calculation Details Step 1: Determine Inlet Properties Using the Steam Property Calculator, properties are determined using Inlet Pressure and the selected second parameter (Temperature, Specific Enthalpy, Specific Entropy, or Quality).

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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 …

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

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 ...

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Bond Ball Mill Work Index (Grindability Tests) May 18, &#; This video was put together by Joshua Wright and Aldo Vasquerizo as a supplemental lecture for University. Live Chat. bond grindability index for fly ash.

3 . 7 Brayton Cycle - MIT

Figure 3.24 shows the expression for power of an ideal cycle compared with data from actual jet engines. Figure 3.24(a) shows the gas turbine engine layout including the core (compressor, burner, and turbine). Figure 3.24(b) shows the core power for a number of different engines as a function of the turbine rotor entry temperature. The equation in the figure for horsepower (HP) is the same as ...

Bond Work Index Procedure and Method

Bond Work Index Tests - Grinding Solutions Ltd

The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined media and ore charge. The Work Index calculated from the testing can be used in the design and analysis of ball mill circuits. The test requires a minimum of 10kg of sample that has been stage-crushed to passing size of <3.35 mm.

Bond Work Index Formula-Equation

The ball mill work index laboratory test is conducted by grinding an ore sample prepared to passing 3.36 mm (6 mesh) to product size in the range of 45-150 µm (325-100 mesh), thus determining the ball mill work index (Wi B or BWi). The work index calculations across a narrow size range are conducted using the appropriate laboratory work ...

bond ball mill work index equation in wills

· Grinding mill modeling has attracted the attention of a number of researchers ever since Bond published his method of energy calculation with an index called Bond work index (Bond 1961). In the 1970s, the population balance or selection and breakage function model was at the forefront of research (Fuerstenau et al. 1973).

CORRELATION BETWEEN BOND WORK INDEX AND …

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 characteristics of a material remain constant over all size ranges, the calcul ated work ...

How to Calculate Grinding Mill Operating Efficiency

For operating efficiency calculations, it is necessary that the efficiency factors are applied so that both work indices, used in the comparison, are on the same basis. Operating efficiency, based upon using operating work indices, is also a useful tool in comparing the variations in grinding mill operations such as: mill speed, mill size, size ...

Determination of work index in a common laboratory mill ...

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 present in most mineral processing laboratories. The …

Comminution testing - JKTech - University of Queensland

A Bond Ball Mill Work Index may also be used in the simulation and optimisation of existing mill(s) and the associated grinding circuit(s). Sample requirements: A minimum of 8 kg of material crushed to nominally minus 10 mm is preferred. JKTech would stage crush the sample to minus 3.35 mm, as required for the Bond Ball Mill Work Index test feed.

GMSG GUIDELINE: DETERMINING THE BOND EFFICIENCY OF ...

Bond Standard Circuit Work Index: Assume the rod mill Work Index of 9.5 applies from the actual rod mill feed sizeof 19,300 mµ (although some of this work might ideally be done by crushers to achieve a rod mill F80 of 16,000 m) to a rod µ mill (circuit) product size of 1,000 µm. W Total = 2.32 + 4.77 = 7.09 very large size (FkWh/t of . 9.70 ...

SIZE REDUCTION - Universiti Teknologi Malaysia

WORK INDEX Include friction in the crusher & power Material Specific gravity Work Index, W i Bauxite 2.20 8.78 Cement clinker 3.15 13.45 Cement raw material 2.67 10.51 Clay 2.51 6.30 Coal 1.4 13.00 Coke 1.31 15.13 Granite 2.66 15.13 Gravel 2.66 16.06 Gypsum rock 2.69 6.73 Iron ore (hematite) 3.53 12.84 Limestone 2.66 12.74

USING THE SMC TEST® TO PREDICT COMMINUTION …

= fine ore work index (kWh/tonne) P. 1 = closing screen size in microns . Gbp = net grams of screen undersize per mill revolution . p. 80 = 80% passing size of the product in microns . f 80 = 80% passing size of the feed in microns . Note that the Bond ball work index test …

Power Calculation Of Impact Coal Crusher Based On Bond ...

Bond work index uses in gold processing - crusher in India. bond crushing work index of copper slag Values of Bond crushing work index will vary from a 8 kWh t for laterite hardcap through to 22 kWh t for banded iron. Power Calculation Of Impact Crusher. Bond 26 2339 3 s rod mill for work index. 19.0 MINERAL RESOURCE AND .

AMIT 135: Lesson 6 Grinding Circuit – Mining Mill Operator ...

Operating data from existing mill circuit (direct proportioning) . Grinding tests in pilot scale, where the specific power consumption is determined (kWh/t dry solids) . Laboratory tests in small batch mills to determine the specific energy consumption. Energy and power calculations based on Bonds Work Index (Wi, normally expressed in kWh ...

Operating work index is not the specific energy consumption

However, Bond Work Indeces are related to the type of equipment to be used (rod mill, ball mill, SAG uses Drop Ball parameter-Kwhr/m3-, so it is …

crushing and grinding calculations by fred c bond pdf

Data Base of Bond Grinding Circuit Efficiencies (under development) References . Annexes: A1. The Bond Crushing WI Test Equipment and Procedure for Bond Efficiency Determinations (Revised March 26, 2015) B1. The Bond Rod Mill WI Test Equipment and Procedure (Revised March 26, 2015) C1. The Bond Ball Mill WI Test Equipment and Procedure. More

Energy efficient mineral liberation using HPGR technology

This so-called mill energy defines an equivalent net energy in the Bond ball mill test to realise the same for a 2.4 meter wet grinding mill. Bond's empirical equation results can thus be reproduced using 60J/rev and the mill test data. Bond's original paper published in 1949 stated that the net energy input to the laboratory scale ball ...

[PDF] A quick method for Bond work index approximate value ...

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 is subjected to errors.

bond rod mill index test

Indicators of grindability and grinding efficiency. Oct 10,, SYNOPSIS Bond's Standard Work Index (SWi) indicates the gri'ldability of an ore, and tis Operamg Work Index (OWi) indicates, Bond grindability test mill is 198 x 10-7kWh, (1)primary grinding in open-circuit rod mills with.

GMSG GUIDELINE: DETERMINING THE BOND EFFICIENCY …

Orway Mineral Consultants Canada Ltd. Mississauga, ON ...

Drop Weight Index (DWi) and the coarse ore grinding index (M ia). Test data from the Bond ball mill work index test is used to calculate the fine grinding index (M ib). The M ia and M ib indices are used to calculate specific energy for the coarse (W a) and fine (W b) components of the total grinding specific energy at the pinion (W

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EF5BM=[ P80+10.3 1.145×P80] ( 3 ) The EF4 formula requires both the rod mill and ball mill work index (rod mill Wi is used to calculate the optimal feed size) and because this is a "single-stage ball mill" calculation, the F80 is actually the rod mill feed size (10,000 µm) from Table 1 and the P80 is the ball mill circuit product. The EF5 factor only applies below 75 µm to ball

Bond Work Index (Energy equation) - Grinding ...

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).