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Ball Mill Operatng Work Index Effeciency

Module 5 Functional Perfomance Of Ball

In the prerequisite module entitled Work Index Efficiency , you have learned about work index analysis to define overall grinding circuit efficiency. In rod milling, you can use work index analysis to relate design and operating variables to overall circuit efficiency. However, you cannot use work index analysis for the same purpose on ball mill

Quantifying And Improving The Power Efficiency Of Sag

Feb 01, 1994 SAG Mill Power kW 2,840 Bal Mil Power kW 1,850 Pebble Crusher kW 0 Nett Power Consumed kW 4,690 Feed Size - PS0 pm 96,000 Product Size - 180 pm 70 Treatment Rate tph 185 Unit Power Consumption kWIt 25.4 Operating Work Index kWlt 21.8 Bond Ball Mill Work Index kWlt 13.0 Efficiency Factor 1.68 2,670 1,650 0 4,320 119,600 SIMULATED At I tat ...

Comparing Energy Efficiency Of Multipass High Pressure

The operating work index method for comparing comminution energy efficiency underestimated HPGR performance due to the large amount of fines generated. ... of the work index of ball mill and ...

Pdf Ore Competence And The Energy Efficiency Of

P80. This is confirmed in Figure 4 where a strong correlation between the Bond operating work index and. the product P80 is se en. ... EFFICIENCY OF AGSAG AND BALL MILL CIRCUITS.

Pdf Comparing Energy Efficiency Of Multipass High

According to the work index efficiency results, the most efficient flowsheet is the jaw crusher-ball mill option Flowsheet D, which is 14 more efficient than Flowsheet A 4.5 Nmm 2. With this method, Flowsheet C appears to be 0.5 less efficient than Flowsheet D. However, the work index calculation is based on F80 and P80 sizes.

A Method Of C Alculating Autogenous Semi

rod mill work index has not been de ned as yet. The ball mill work index is con rmed at 16 kWht. The operating work index, though, is in the range of 21 kWht to 25 kWht showing high inef ciency. This raises the point that, in some cases, the Bond EF4 oversize factor calculation is not suf cient to compensate

Ball Mills An Overview Sciencedirect Topics Ball mills. The ball mill is a tumbling mill that uses steel balls as the grinding media. The length of the cylindrical shell is usually 11.5 times the shell diameter Figure 8.11. The feed can be dry, with less than 3 moisture to minimize ball coating, or slurry containing 2040 water by weight.

The Influence Of Mill Speed And Pulp Density On The

Operating Work Index Wio or KwhT passing a certain ... mill with a 30 mm graded ball charge and a 30 filling degree. ... The best grinding efficiency measured in terms of Operating Work Index Wio or KwhT passing a certain screen is obtained with the lowest speed.

Modelamelunxen Sgi

Amelunxen SGI Model. This is a model that estimates the specific energy consumption of a SAG or AG mill plus ball mill circuit using the equation by Amelunxen 2014 for E SAG and the classical Bond work index equation for E ball substituting CF ball in the place of the Rowland efficiency factors.. The model requires manual calibration factors for both equations CF SAG and CF ball ...

Energy Use Of Fine Grinding In Mineral Processing

Dec 18, 2013 For P80s finer than 75 m, 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.

Agsag Mill Circuit Grinding Energy Requirement How

operating work indices were calculated for each circuit. These are plotted for each circuit and shown in Figure 6. The ball mill values largely followed the Bond laboratory work index results, which were also obtained for each ore type. The AGSAG operating work indices show their usual elevated levels compared to those from the ball mill circuit.

Pdf A Summary Of Energy Efficiency Opportunities For The

Work Index Efficiency Ratio BBWiOWi and the Actual Ball Mill Media Size Divided by the Recommended Media Size Based on Azzaronis Equation ... Operating work index . kWt . 32.5 . 43.0 ...

A More Sustainable Approach To Assessing Comminution

Jun 01, 2009 The most common method of assessing comminution efficiency is to use the Bond operating work index Bond, 1952 . Even though this method works fairly well for rod and ball mill circuits, it however, does not provide the same accuracy when applied to AGSAG mills or the wider range of comminution devices such as HPGR, tower and stirred mills ...

Modelbondbarratt Sab Model

The resultant operating work index of the ball mill will vary according to the ratio of the ball mill, rod mill and crushing work index values and for an Andean copper porphyry is typically in the range of 80 of the measured ball mill work index value. Testwork Required. Bond ball mill work index Bond rod mill work index

Using The Bond Work Index To Measure Operating Comminution

Nov 01, 1998 Using the Bond work index to measure operating comminution efficiency ... and Luckie, P.T., 1984, Process Engineering of Size Reduction Ball Milling, SME, Chapter 4, p. 76. Google Scholar Bond, F .C., 1952 ... Rowland, C.A. Using the Bond work index to measure operating comminution efficiency. ...

Bond Work Index An Overview Sciencedirect Topics

The ball mill work index laboratory test is conducted by grinding an ore sample prepared to 100 passing 3.36 mm 6 mesh to product size in the range of 45-150 m 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 ...

Ore Competence And The Energy Efficiency Of

Figure 4 Trend in Bond Operating Work Index with Product P80 VALIDITY OF THE BOND OPERATING WORK INDEX FOR EVALUATING AGSAG MILL EFFICIENCY Researchers such as Hukki have challenged the validity of Bonds equation, at least outside the range of feed and product sizes treated in ball mills.

Tower Fine Milling Experience At Mount Isa

The efficiency arose from the small ball size and relatively coarse feed and coarse product. The millcyclone circuit had a higher operating work index relative to the mill, indicating inefficient cyclone operation. A high vortex-finderspigot diameter ratio 8122 mm caused a very low water and solid split to underflow 9 and ...

Estimate The Power Require To Grind 100 Tonneh Ore

Estimate the power require to grind 100 tonneh ore in a ball mill operating circuit with hydro cyclone at a circulating load of 300.Rod mill discharge has a P80 of 0,25 .Flotation feed size required correspond to 80 -65 mesh.The bond work index, Wbm is determined to be 14.7kWhTonne.For simplicity,consider the product of all efficiency for power

Modelbondbarratt Sabc Models

The ball mill oversize feed factor EF 4 BM is always calculated with the rod mill work index for the optimum feed size and the ball mill work index for EF 4 BM. The model assumes that the calculated value of E ssbm the specified contingency is greater than the sum of E sag E peb

Pdf A Quick Method For Bond Work Index Approximate

A quick procedure with two grinding cycles for the determination of the Bond. work index approximate value is exactly the same as in the first two grinding cycles of. the standard Bond test and ...

Modelbond Hpgr And Ball Mill

where CF is the Essbm calibration factor in the Circuit Settings for ball mill operating work index versus laboratory ball mill work index. A value of zero means use the BondRowland SSBM formula to predict E ball, a value of -0.05 means use 5 less than BondRowland SSBM formula to predict E ball. CF is a negative number if Wi O is less than ...

Energy Efficiency In Mining 34 Retrofits Metso Outotec

Dec 18, 2018 By adding a VTM-3000 their overall specific energy consumption increased, which normally would mean that the circuit was more inefficient. However, in this case their operating work index actually dropped. This was a successful application of the Vertimill technology from both an energy efficiency and value recovery points of view.

Improved Characterisation Of Ball Milling Energy

Methods for assessing the energy consumption of the Bond Ball Mill are discussed. The average reduction in Work Index of HPGR products was 1.9 kWht. A similar magnitude of reduction was observed in the Size Specific Energy. Ball milling efficiency can vary significantly independently of HPGR operation.

Achievement Of High Energy Efficiency In Grinding Mills

Bond ball mill work index kWht 15.8-23.5 19.1 21.8 Bond rod mill work index kWht 16.8-18.4 17.6 17.6 Abrasion Index, AS test 0.082-0.591 0.282 0.346 SMC Dwi 4.7-7.85 7 7.9 Unconfined compressive strength Mpa 39.4-105.0 86.6 86.6 Value Design Criteria The initial design criteria was to treat 4.0 Mta throughput increasing to 4.5 Mta by adding one

Pdf Operational Work Index For Grinding Plants

An global operational work index, Wiog, is defined for a conventional grinding plant consisting of a rod mill followed by three inverse hydrocyclone-ball mill grinding circuits and its value is ...

Using Comminution Energy Intensity Curves To Assess

respect to the effect of ore hardness, circuit efficiency, grind size, and feed grade. The first energy curve shows the impact of ore hardness as assessed using the Bond work index comparative methodology. Both the Bond work index BWi and the operating work index OWi are presented as separate overlayed curves Figure 1. The BWi is an

Grinding Circuit At Mouteh Gold Mine

Where operating work index kwht isWiop, mill power draw kw isW, Q is mill throughput th andP80,F80 are respectively mill product and feed size distributions. Operating Bond index is not comparable to laboratory standard Bond index therefore a few correction factors should be multiplied to obtain of corrected operating Bond index13, 17.

Grinding Circuit An Overview Sciencedirect Topics

The SAG mill was designed to treat 2,065 t h 1 of ore at a ball charge of 8 volume, total filling of 25 volume, and an operating mill speed of 74 of critical. The mill is fitted with 80 mm grates with total grate open area of 7.66 m 2 Hart et al., 2001 .

Comminution Testing Jktech University Of Queensland

Jul 30, 2020 A Bond Ball Mill Work Index may also be used in the simulation and optimisation of existing mills and the associated grinding circuits. 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.

Benchmarking Specific Energy Consumption Models

Ball mill operating work index reduction versus laboratory 5 microcrackingphantom cyclone effect Secondary crusher WiO is 18.1 kWhtonne versus laboratory determination 27.7 kWht. Show details of benchmarking. Benchmarking BondRowland SSBM Circuit Specific Energy Consumption - Tropicana

Quantifying The Energy Efficiency Of Fine Grinding

In the first survey the ball mill was underperforming due to the low density in the mill, which was rectified in the second survey. The ball mill was grinding to a P 80 of 50 to 70 m, therefore the traditional marker size 75 m was not applicable, and this can be seen by the increase in SSE for coarser sizes as the marker size approached P ...

Question 3 25 Marks A Ball Mill Is Operating At An

Transcribed image text Question 3 25 marks A ball mill is operating at an efficiency of 80 with a filling volume of maximum 1.32 m The ore has a W of 19 kWon. The RD of the crushing balls are 5.0. The charge volume is about 45. Calculate the following a What length and diameter of mill is required to reduce ore sizes from 4 mm to 200 um

Application Of Operating Work Indices In Autogenous

Mill operators have long used operating work indices to evaluate grinding circuit efficiency, with great utility. Operating work indices can be used to evaluate individual units in a conventional circuit or the overall performance of an autogenous-semiautogenous AG-SAGball mill circuit, but they are of limited value in evaluating AG-SAG and ball mill sections separately.

Operating Work Index Is Not The Specific Energy Consumption

Oct 24, 2018 The work index can either be measured in the laboratory the Bond ball mill work index determination is a common example or it can be calculated from the operating performance of a milling ...