Key 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 18838072829A Bond laboratory ball mill work index test was conducted using a closing screen of 150 m which gave a P80 of 108 m. A calculation is required to be carried out to estimate the specific energy ...
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 18838072829Process Engineering of Size Reduction: Ball Milling. Society of Mining Engineers of the American Institute of Mining, Metallurgical and Petroleum Engineers (AIME) Inc, ISBN, New York, 556 pp.
WhatsApp: +86 18838072829The 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 ...
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 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 1883807282921 CONCLUSIONS Continued In the present work, equations were also derived, giving: zthe ballmill power drawP as a function of its dimensions: internal mill diameter D and length L, zthe ballmill 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 ballmill dimensions (D and L), when ...
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.
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 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 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 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 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) and liable to experimental errors. This work contributes to obtaining new models for rapid Bond Work Index.. View via Publisher.
WhatsApp: +86 18838072829The Bond work index, Wi, 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 ...
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 ...
WhatsApp: +86 18838072829Wi Bond Work Index Ws Specific energy correction for size distribution (kWh/t) WiBM Bond Ball Mill Test Work Index (kWh/t) 3. KEYWORDS Autogenous Grinding (AG), Ball mill, Bond Work Index (Wi), Comminution circuit, High Pressure Grinding Rolls (HPGRs), Rod mill, SemiAutogenous Grinding (SAG), Specific energy (W) 4. INTRODUCTION AND BACKGROUND
WhatsApp: +86 18838072829MenéndezAguado et al. examined the possibility of determining the work index in a Denver laboratory batch ball mill with the same inner diameter as the Bond ball standard mill. The research was performed on the size class of 100% − mm using samples of gypsum, celestite, feldspar, clinker, limestone, fluorite, and copper slag.
WhatsApp: +86 18838072829a modified Bond ball mill procedure (Mod Bond) was developed by MinnovEX Technologies (now SGS) which requires of sample crushed at minus The charge is milled with the standard Bond ball mill for a set time. A particle size analysis is performed on the feed and ground product, and a modified work index is calculated using a ...
WhatsApp: +86 18838072829An alternative mill ball charge is proposed that closely approximates Bond's original total ball mass, number of balls and ball surface area. Results of 30 Bond Work index tests of six pure materials (calcite, magnesite, labradorite (feldspar), quartz, andalusite and glass) using closing screen apertures (P 1) values of 500, 250, 125, 90 and 63 ...
WhatsApp: +86 18838072829This Table of Ball Mill Bond Work Index of Minerals is a summary as tested on 'around the world sample'. You can find the SG of each mineral samples on the other table. Source 1. Source 2. Source 3. Source 3. Source 4.
WhatsApp: +86 18838072829Use this online formula to calculate a Ball Mill, Rod Mill or SAG Mill Operating Work Index. Based on Fred Bond's work you can estimate the energy used into your grinding circuit. This is the most accurate and informative method, but much of the data necessary for its application is not yet available. A) Total Apparent Volumetric Charge ...
WhatsApp: +86 18838072829The ball mill grindability test is used for describing ore hardness and it is so widespread that the Bond Work Index generated from the test is often referred to as an ore characteristic. The ore resistance to grinding and energy consumption can be expressed using the work index and Bond's Third Theory.
WhatsApp: +86 18838072829Bond Ball Mill Work Index in kWh/t. Bond Rod Mill Work Index in kWh/t. Pressure in kPa. 80110. Circulating load in % 250350. Overflow product x P,80 in ...
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