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As the operating work index ( W io ) for each of the feeds was not known before the grinding tests, the Bond Work Index was used in the calculations. The operating work index would have been higher than W i due to the fine grinding occurring. This would result in the estimated top ball sizes being higher than those estimated by the equation.
· A Bond Ball Mill Work Index test may be required for the design of a new mineral processing plant . It is determined by Bond Ball Mill Grindability test in a lab using a Bond Mill. Grindability is the number of net grams of ( screen ) undersized product … More Details
The Encyclopedia of Arkansas explains that commercial mining of quartz is rare and occasionally consists of the use of explosives to first expose the quartz, followed by the operation of small hand tools such as chisels and rock picks to extract portions of the mineral from a quarry. ... silica quartz quarry for sale - Grinding Mill China.
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.
The grindability of an ore in the process of mineral dressing can be determined by use of the Bond work index (Wi). This index is determined on …
A Bond's Ball Mill Work Index (BWi) was determined for the supplied sample at a closed size of 100 mesh (150 microns). The work index of the sample was 15.55 kWh/st. The results indicate that the sample would be considered hard. A Bond Abrasion Index (Ai) was determined for the supplied sample. The abrasion index of the sample was 0.798.
Results of 30 Bond Work index tests of six pure materials (calcite, magnesite, labradorite (feldspar), quartz, andalusite and glass) using closing screen apertures (P1) values of 500, 250, 125, 90 and 63 μm are analysed.
andesite bond ball mill work inde rolling mill pulverizer. andesite bond ball mill work inde rolling mill pulverizer. Comminution Handbook Edited by Alban Lyn . where: Wib is the ball mill Work Index in kWh/short ton Pi is the test sieve aperture size in μm Gbp is the ball mill grindability in grams/rev P and F are the 80 per cent passing sizes of the feed and product …
Ball mills usually operate at 65% to 75% of the critical speed. The critical speed is calculated as under [5]. R r g 2 1 n c (2) 2.1.3 Work Index: Work index is defined as the gross energy required in kilowatt-hours per ton of feed needed to reduce a very large feed to such a size that 80% of the undersize passes through 100-µm screen [5].
The Bond Index conforming rod charge consists of: 6 rods of 1.25" diameter and 21" length. 2 rods of 1.75" diameter and 21" length. The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill.
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 ).
Where, WioACTis the Actual Operating Bond Work Index (kWh/t), W is the specific energy input (kWh/t), P80 is the 80% passing size of product (µm), and F80 is the 80% passing size of circuit feed (µm). 2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal
Over the last decades, several reliable mathematical models have been developed for simulating ore comminution processes and determining the Work Index. Since Fred Chester Bond developed the Work Index standard procedure in 1961, numerous attempts have been made to find simpler, faster, and economically more advantageous alternative tests. In this …
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 …
Insmart Bond Work Index Ball Mill, work index Mill
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.get price.
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 …
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 ...
Bond Ball Mill Work Index For Pure Quartz. Bond Work Index FormulaEquation. See this useful summary Table of Bond Work Index by Minerals. For any circuit, whether a crushing circuit, a rod mill, or a closed ball mill circuit, the Work Index always means the equivalent amount of energy to reduce one ton of the ore from a very large size to 100 um.
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 more complex than just specific energy consumption ...
Ball mill design calculation software free ball mills manufacture ball mill designpower calculation 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 …
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 and
FIGURE 8: ROD MILL/BALL MILL WORK INDEX RATIO v. UNCONFINED COMPRESSIVE STRENGTH 100 200 300 400 UCS (MPa) 0 0.5 1 1.5 2 WiRM/WiBM (metric) Siddall et al (1996) identified the ratio of Bond rod mill Work Index and ball mill Work Index as being indicative of an ore's compentency. Figure 8 plots this ratio versus UCS; no trend is apparent ...
typically used. The rod mill work index is computed with an equation very similar to that of the ball mill test, as follows: It is common to observe a difference between the rod mill and ball mill values for a given ore type. These differences may be caused by a variation in ore hardness by size (12.5mm for RWI and 3.35mm for BWI), and/or grain ...
Bond estimated the amount of wear in terms of kilograms per kWh based on the abrasion index, A;, i.e., Wet Ball Mill = kg kWh = 0.16(A i-0.015) 0.33; Dry Ball Mill = kg / kWh = 0.023A i 0.5; Replacement Ball Size. Rowland and Kjos proposed the use of their equation for the determination of … Read More
Bond Ball Mill Work For Pure Quartz. The standard Bond Ball Mill Work Index test procedure is firstly to stage crush the feed to minus 3 35mm and size a representative sample The test then involves a series of batch grinds in a standard Bond mill A Bond mill is 0 305m by 0 305m with rounded corners a smooth lining and runs at 70rpm The charge ...
Overall, the samples tested exhibited soft to moderate hardness with Bond ball mill work index values, at P80 of 106 microns, ranging from 9.7 for the 8 Zone composite, to 17.1 in the strongly silicified Austin composite. About Madsen
XMGQΦ305 Grinding Work Index Ball (Rod) Mill . Description; XMGQΦ305 Grinding Bond Ball (Rod) Mill is mainly applied for testing the grinding work index of the material of every kinds of ores, slag, etc. Under the specific rotation …
Correction of Bond Ball Mill Work Index Test for Closing Mesh Sizes It is commonly known that one must run the Bond ball mill work index test such you pick a closing mesh to give a P80 close to desired grind size.
Bond Ball Mill Work Index (BWI) testing was performed on nine samples. The indices varied from 16.9 to 20.6 kWh/t, with an average of 18.6 kWh/t. Bond Abrasion Index (AI) testing was performed on six samples and indices ranged from 0.211 g to 0.554 g, with an average Ai of 0.381 g.