You need a twostage solution, first stage opencircuit mill and then second stage closedcircuit 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 (+ mm) and the Bond ball mill work index for the fine component ( mm).
WhatsApp: +86 18838072829The Bond work index, W i, is defined in a Bond ball mill on the samples of standard size − + 0 mm. In practice, it is possible to find materials of nonstandard size that are finer than mm.. In this work, a procedure for the calculation of the Bond work index is suggested for cases when the Bond grindability test is conducted on samples of nonstandard size.
WhatsApp: +86 18838072829Istilah BWI sendiri dapat disebut lagi menjadi Bond Ball Mill Work Index (BBWI) atau Bond Rod Mill Work Index (BRWI). Ini tergantung dari media gerus yang digunakan selama percobaan, apakah bola baja atau batang baja. Untuk menghitung BWI digunakan formula sbb: Dimana. Wi = Nilai bond work index yang dicari (kwh/ton)
WhatsApp: +86 18838072829However, Bond Work Indeces are related to the type of equipment to be used (rod mill, ball mill, SAG uses Drop Ball parameterKwhr/m3, so it is more complex than just specific energy consumption ...
WhatsApp: +86 18838072829The Bond's BallMill Work Index is a measure of the resistance of the material to grinding in a ball mill. This Index is widely used in the industry for comparing the resistance of different materials to ball milling, for estimating the energy required for grinding and for ball mill scaleup.
WhatsApp: +86 18838072829Figure 1 shows a histogram of Bond ball mill work index frequency from MacPherson Consultants (ARMC). This database covers a fraction of all the tests performed by ARMC over the years and around the world. It shows that the ball mill work index is normally distributed with an average of and a median of kWh/t. bOnd rOd mill ...
WhatsApp: +86 18838072829Similar to a Comparative Work Index, this test is an open circuit dry batch grindability test run in the standard Bond Ball Mill for a set time. It can be used at mesh sizes from 65 to 200 mesh (normally 100 mesh). The test requires calibration against the standard Bond Ball Mill Work Index test to estimate the Work Index.
WhatsApp: +86 18838072829WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index (kWh/t) WioACT Actual Operating Bond Work Index determined from measurements on the circuit (kWh/t) 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 ...
WhatsApp: +86 18838072829The Bond Work Index (Wi) is a common technique for the estimation of hardness and energy requirement for comminution using ball mills. However, this technique is timeconsuming (close to 5 hours ...
WhatsApp: +86 18838072829The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. ... Kinetic grinding test approach to estimate the ball mill work ...
WhatsApp: +86 18838072829Bond Work Index (BWI) Hardgrove Grindability Index (HGI) tests for biomass coal. • BWI can predict the potential for mill choking of biomass in a tube and ball mill. • HGI is a poor method of predicting grindability of biomass in vertical spindle mills. • Pellets should be composed of predensified particles close to the target size. •
WhatsApp: +86 18838072829A 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., 2006). This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required ...
WhatsApp: +86 18838072829Key words: Comminution, Bond work index, Grinding, Crushing, Ball mills, Rod Mills. Theoretical efficiency In their book Process Engineering of Size Reduction Ball Milling, Austin, Klimpel and Luckie (1984) stated that, "We have tried throughout this book to avoid the use of the term grinding efficiency because the degree of conversion of ...
WhatsApp: +86 18838072829KB= Bond's work index, energy per unit mass, di= Initial diameter of particle; dn= Final diameter of particles. The bond's useful work index is a useful way for comparing the efficiency of milling operation. This is useful for rough mill size. Procedure to verify the laws of size reduction using Ball mill
WhatsApp: +86 18838072829Bond ball mill work index (BBMWI) test is a standard test used to measure the ball mill work, which is calculated in accordance with the procedure proposed by the Bond [21]. The BBMWI determines how much energy is needed to grind a sample of ore in a ball mill [22]. This measurement is expressed in kilowatthour per ton (kWh/t), which is the ...
WhatsApp: +86 18838072829The Bond ball mill grindability test is run in a laboratory until a circulating load of 250% is developed. It provides the Bond Ball Mill Work Index which expresses the resistance of material to ...
WhatsApp: +86 18838072829The Bond ball mill work index (Wi BM, or BWi) conducted from a feed size of approximately 2 mm to a product size on the order of 100 µm. The Bond rod mill work index (Wi RM, or RWi) conducted from a feed size of approximately 10 mm to a product size on the order of 1 mm. The Bond crushing (impact) work index (Wi C, CWi, LEIT or IWi) conducted ...
WhatsApp: +86 18838072829In 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
WhatsApp: +86 18838072829The results showed that using the nonstandard mills (between 20 and 35 cm in diameter), the Bond´s model constants (α=; β=, and γ = ), are unable to predict the Work Index properly. Therefore, these constants must be recalculated using linear models based on mill diameter. With the models proposed for α, β, and γ, the Bond ...
WhatsApp: +86 18838072829Bond Ball Mill (BBM) Standard Test The procedures to carry out the Bond grindability tests in ball mills and rod mills are outlined in Sections and They are usually referred to as the standard tests, but it
WhatsApp: +86 18838072829A standard Bond mill (Fig. 1) was designed to perform the work index tests and determine the energy consumption of various s mill has a round internal housing at the corners, has no lifters, and is for dry grinding. The inner diameter and the length are m, and the ball load is % of mill volume (equaling a total weight of kg).
WhatsApp: +86 18838072829The reason for this variation in ball mill work index is because the ore at Mt. Milligan has an intrinsic exponent of in the 100 µm to 200 µm size range, not the exponent empirically measured by F. Bond. The work index increase between 100 µm and 76 µm is due to a porphyritic grain size that causes a spike in energy
WhatsApp: +86 18838072829The Work Index (BWi) is calculated according to Fred Bond's Equation. Bond Work Index for Testing Procedure. Cleaning and Storing of Ball Mill Charge after the Bond Work Index Procedure is done: Add about 500 g of silica sand into the mill containing the ball charge. Seal the mill. Rotate for 20 revolutions to clean.
WhatsApp: +86 18838072829In particular, the Bond work index (wi) is considered a critical parameter at an industrial scale, provided that power consumption in comminution operations accounts for up to 40% of operational costs. Despite this, the variability of wi when performing the ball mill Bond's standard test is not always understood enough.
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