The standard Bond method is the most acceptable method for designing and selecting ball/rod mills described by their basic parameter called work index (W-i). The standard Bond method is a tedious ...
In the second step of the testing method, the test is based on the Bond ball mill. The product from the first step is then used for determination of the required ball mill energy for the secondary grinding stage to reach the target grinding size. The empirical formula to calculate Bond Mill Work Index (BWi) is presented in the equation (2)
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 ...
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.,
Bond Work Index (BWI) Test. Celtest have the capability to carry out the Bond Work Index (BWI) Test in accordance with EPRI Report CS3612 : FGD Chemistry and Analytical Method Handbook, Volume 2 . The BWI is used to estimate the required mill power per ton of product (Specific Energy). The specific energy requirements and the desired production ...
Bonds Work Index Ball Mill. Bond method for ball mill work index test a bond ball mill work index test is a standard test for determining the ball mill work index of a sample of ore it was developed by fred bond in 1952 and modified in 1961 jkmrc co 2006this index is widely used in the mineral industry for comparing the resistance of different materials to ball milling for estimating the ...
WiRM Bond Rod Mill Test Work Index (kWh/t) WiSTD Standard Circuit Bond Work Index (expected or designed) used for circuit design. Specific energy requirement at the drive pinions. 3.KEYWORDS Work Index, Work Index Efficiency, Bond Work Index testing 4.INTRODUCTION AND BACKGROUND The Bond method allows for quantification and com-parison of ...
Chapter 3. Size Reduction and Energy Requirement - Scribd. Apr 19, 2010 ... Wj is known as the Bond Work Index and represents the work .... 3.3.4 Bond Ball Mill Standard Test The method …
a simple yet practical alternative for the standard Bond method. Keywords: work index, Bond method, kinetic grinding test, grindability, ball mill Introduction The standard Bond (1952; 1961) method is widely used in the course of design, selection, scale up, energy …
Decision-making on selection of SAG mills increasingly uses the methods of sizing the milling power based on laboratory tests on grindability of minerals. This article considers one of such methods allowing determination of mill characteristics based on the Bond work indexes of crushing, rod milling and ball …
Bond Test. Determining the Bond work index is a standardized method for characterizing the comminution performance of mineral samples. CEMTEC uses this method for designing rod and ball mills. The comminution performance is, just like the desired comminution step and the production capacity, crucial for determining the required mill size. ...
puritic ore, calculated Bond work index is higher with different circulating loads, the Bond work index is higher with lower circulating loads. The purpose of this study to determine the effects of circulating load (CL) and test sieve size (P;) on the Bond ball mill grindability (Ght,) and work index (W,) with natural amorphous silica.
an average work index of 15.5 kWh/t. A very broad range of results was received, characterising the 'standard ore' from medium to very hard. A disappointing result considering the reliance on this test globally for design and optimisation. An improved method using less mass compared to the Bond Ball Mill Work Index test.
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 ...
ization data generated from the SMC Test® (see Annex A) and the Bond Ball Mill Test Work Index (WiBM; GMG, 2016a), and the Morrell equations and their application (see Annex B). A worked example is provided in Annex C. 5. SCOPE The Morrell method can be used to predict the specific energy of comminution circuits, where such circuits include
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
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.
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 …
The results from conducting the SMC Test® are used to determine the so-called 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 circuits ...
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, which is used at Anaconda Research Center to approximate the work index, is an alternative procedure to ...
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.
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. A quick method ...
· It can be seen that in the regime in which the Bond equation is valid, energy use increases exponentially as product size decreases with constant feed size, with an exponent of (approximately) −0.5. For P80s finer than 75 μm, the Levin test, a modified Bond ball mill work index test, may be used to predict grinding
Standard Bond Ball Mill Grindability Test Method-Procedure Here is the old Allis-Chalmers Bond Work Index Grindability Test Procedure. The standard feed is prepared by stage crushing to all passing a 6 mesh sieve, but finer feed can be used when necessary.
A new size laboratory ball mill for Bond Work Index determination is described. Just as the standard Bond grindability test, this method is a locked-cycle dry grinding and screening process that ...
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.
test. This isn't reported in a standard ball mill work index test, but the method of Levin, 1989, can be used to calculate a "Levin B value" which is the kW·h per revolution of a Bond laboratory ball mill. Dividing ball mill grindability (g of product/rev) by the Levin B (kWh/rev) gives the desired units of measurement (g/kWh).
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 ...
This video was put together by Joshua Wright and Aldo Vasquerizo as a supplemental lecture for University of Nevada Reno.If you have any questions, need advi...
In this regard calculation of work index of limestone made by standard Bond grindability test. Ball mill was employed to conduct the grinding test of seven different samples. Among all seven samples collected from the different faces of quarry, Bond work index of limestone Face4A results less than 20kwh/t, remaining 6 samples are marked as hard -
Bond Work Index Procedure and Method 911 . 06/06/2015· 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
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.
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 T) according to Equation 7. W i = 4.K.M i.[Pf(P)-Ff(F)] (6) W T = W a + W b ...