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 recovery and/or mill liner wear and tear.Calculate the work index of the ore by using the formula: W is the work index, P i the MOG in microns, G the grindability in gms/rev, P the product size and F the feed size in microns, both at 80% passing size. 4.45 Wi = -----P i 0.22 G 0.82 1/√P 80 - 1/√F 80

The parameter Wi, known as the work index of the ore, is obtained from batch bench tests first devised by Bond (1961). The power calculated on using equation 1, (Bond, 1961; Rowland and Kjos, 1978), relates to: 1) Rod milling – a rod mill with a diameter of 2.44 meters, inside new liners, grinding wet in open circuit.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.

The Bond_Op. Work Index spreadsheet was designed to estimate the Operational Work Index of a given grinding installation of known dimensions and operating conditions, based on the traditional Bond's Law and the Hogg & Fuersteneau Power Model (see Mill Power_Ball Mills spreadsheet for further details on such model).The ultimate crystalline size of graphite, estimated by the Raman intensity ratio, of 2.5 nm for the agate ball-mill is smaller than that of 3.5 nm for the stainless ball-mill, while the milling ...

The work index expresses the resistance of the material to grinding. It represents the kilowatt hours per tonne required to reduce the material from theoretically infinite feed size to 80 passing 100μm (Wills and Napierpercent -Munn, 2006). Bond devised several methods for predicting ball-mill and rod-mill energy requirements andThe work performed included analysis of operating performance data from 49 mills and included extensive determinations of the Bond Abrasion Index for different ore types. For an improved understanding, the wear rate constant is directly related to the grinding media consumption rate expressed in grams of steel per kWh drawn by the mill, using ...

Ball mill design requires a Bond work index, BWi, for ball mills at the correct passing size; SAG mill design requires an appropriate SAG test, for example, SPI (Chapter 5). Flotation design needs a valid measure of kinetics for each sample, including the maximum attainable recovery and rate constants for each mineral (Chapter 12).Dec 17, 2018· G = ( HGI – 13 ) / 6.93 (14) where, G = grindability of the mill, g/rev. Mill Power: Bond's theory enables estimation of specific power consumption ( kwh / Ton ) from the work index, Wi of the material being ground which conforms to mill motor output power of an 8 ft diameter wet grinding overflow ball mill in closed circuit.

The work index of a particular material is determined in the laboratory by conducting the standard Bond grindability test. Bond developed separate tests for the rod mill and the ball mill. The simplified test method described in this paper is an alternative procedure to the ball mill grindability test.This reverts to the Morgärdshammar method and is similar to the AM calculation 3.6 Tower Mill The tower mill calculation is based on the ball mill design sheet, but is simplified in that the mill design section is omitted. A simple tower mill factor of 70% allows the mill power to be estimated. MILLCALCv2a 5 19/02/2004

2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal WiSTD= –––––––––––– (3) 10 10 (––––－––––) √￣P80 √￣F80 The Bond Standard Circuit is the "conventional" crush-ing-rod-ball milling circuit that was popular circa 1950 toPdf Mastercam Handbook Volume 2 For Mastercam X3 Date Agus. Molecules Free Full Text Ball Milling Promoted N Heterocycles. Design Construction And Operation Of A High Energy Mill For. Http Www Bicoinc Com Assets Ballmill Operatingmanual Pdf. Https Engineeringresearch Org Index Php Gjre Article Download 1562 1493.

The laboratory procedure for running a Bond ball mill work index test requires that the operator choose a closing screen sieve size. The instruction is to choose a sieve size that results in the ...The maximum power draw in ball mill is when ball bed is 35-40 % by volume in whole empty mill volume. Considering that ball bed has a porosity of …

Rowland, C.A., 1978, "Determination and use of operating work indices in controlled grinding circuits–A proposed concept," Mill Operator's Conference and Exhibit, Northwestern Branch, Australasian Institution of Mining and Metallurgy, Mt. Isa, Queensland Australia, June.A Bond rod mill work index test (BRMWI) is a standard test for determining the rod mill work index of an ore sample [21]. The BRMWI is a measure of the resistance of the material to crushing and grinding in a rod mill and is used to calculate the grinding power needed for a given material parcel regarding rod mill grinding conditions.

80 sizes typically reached by conventional ball milling. The delineating size between coarse and fine grinding is 750 µm. SMC test results are used to determine the 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 MBall Mill Design/Power Calculation. Jun 19, 2015· 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 ...

For overflow ball mills, the charge should not exceed 45% of the mill volume . For grate discharge mills, the charge should occupy about 50% of the mill volume . Bond developed a relationship that can be used to determine the percent charge by volume as a function of the vertical height above the charge, He, and the radius of the mill, R, i.e.,ball mill work index calculation xls. ... For every bond ball mill work index test carried out at jktech a standard report is issued the report details the bond test procedure method and presents the results including f80 p80 grindability and work index further interpretation of the results is available if required frequently asked questions ...

rod mill work index has not been de ned as yet. The ball fi mill work index is con rmed at 16 kWh/t. The operating fi work index, though, is in the range of 21 kWh/t to 25 kWh/t showing high ineffi ciency. This raises the point that, in some cases, the Bond EF4 oversize factor calculation is …= SAG mill feed sample mass, grams The ball mill pinion energy is determined from the Bond the Third Theory of Comminution : S d-BWI = 1.102 * 44.5 / (P cs 0.23 G pb 0.82) / (10 / P 80 1/2 – 10 / F 80 1/2) where : S d-BWI = Bond ball mill work index on SAG ground ore, kWh/ton ground F 80 = 80% passing of SAG ground of the test feed size ...

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 ...two. Results of Bond ball mill tests conducted with closing screens of 75 µm or finer are to be treated with caution. The Bond Work Index relationship has been noted to apply down to approximately 70 m, and perhaps no finerµ, without making qualifications. Calculations: First, calculate the actual Operating Work Index, WloACT-, of the

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Enter the number of lifters that are exposed above the mill charge. Fractions are acceptable and should be used in the case where the charge does not sit uniformly in the mill. For example, you may have 29 rows exposed at the discharge end of the mill, and only 28 exposed at the feed end.ball mill calculation for cement plant. Process analysis and energy efficiency improvement on Portland ball mill calculation for cement plant Improving grinding efficiency in closed circuit cement ball mill A Standard Bond work index calculation cem