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 proprietary model. The Mod Bond results must be calibrated against sufficient standard Bond ball mill work indices, typically 10% of the total.
WhatsApp: +86 18838072829The commonly used grindability tests included in the database are the Bond work indices for ball milling, rod milling and crushing; the drop weight test results A, b, A×b, DWi, Mia, Mic, Mih and ...
WhatsApp: +86 18838072829The Bond ball mill grindability test is one of the most common metrics used in the mining industry for ore hardness measurements. The test is an important part of the Bond work index methodology ...
WhatsApp: +86 18838072829It provides the Bond Ball Mill Work Index which expresses the resistance of material to ball milling. This happens after 710 grinding cycles, which shows that the procedure is a lengthy and ...
WhatsApp: +86 18838072829A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints. Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles ...
WhatsApp: +86 18838072829The Bond work index most commonly referred to is the BBM work index. This value is obtained in a 12" 12" laboratory mill running at 70 rpm, with rounded inner edges and without lifters. The grinding charge is comprised of a distribution of steel balls with several diameters. Table1shows the original Bond proposal [13], while the last Bond
WhatsApp: +86 18838072829In conjunction with the Bond ball mill work index they can be used to accurately predict the overall specific energy requirements of circuits containing: • AG and SAG mills. ... As a general rule Bond ball work index tests are recommended when SMC Tests® are carried out as this provides valuable additional information on the way that much ...
WhatsApp: +86 18838072829This is because work index frequently changes as a function of the product size in comminution. If target grind size during a project is changed, or if the test is run at the wrong product size, then it is necessarily to provide a correction. The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis
WhatsApp: +86 18838072829It is a wellknown fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. In this study, a variability bysis is carried out with the Bond standard grindability tests on different critical metal ores (W, Ta), ranging from coarse grinding (rod mills) to fine grinding (ball mills). The relationship between wi and grinding size did not show a clear ...
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 18838072829CERAMIC LINED BALL MILL. Ball Mills can be supplied with either ceramic or rubber linings for wet or dry grinding, for continuous or batch type operation, in sizes from 15″ x 21″ to 8′ x 12′. High density ceramic linings of uniform hardness male possible thinner linings and greater and more effective grinding volume.
WhatsApp: +86 18838072829The Work Index is used when determining the size of the mill and grinding power required to produce the required ore throughput in a ball mill. 2. Procedure Bond Ball Mill Grindability The sample was crushed to 100% passing 6 mesh (), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
WhatsApp: +86 18838072829This study aims to develop a new approach toward estimating the Bond ball mill work index (BBWI) by applying a series of kinetic grinding tests with Bond standard mill. Establishing a series of ...
WhatsApp: +86 18838072829Typical Mill Circuit Represented by the Bond Ball Mill Test. The procedure for the work index test bases the BW i value on the calculation of new fines generated in the test. This means that the fraction of fines in the feed should not influence the test result significantly, if at all.
WhatsApp: +86 18838072829The results of the "raw" Bond ball mill work index values for dacite, basalt, and copper ore samples on coarse and fine samples are shown in Table 1. The raw work index is computed using Eq. (10) for the laboratory test results for both "valid" (F 100 = mm) and "invalid" (F 100 ≠ mm) feed to the test.
WhatsApp: +86 18838072829The grinding jar of the Bond Index Ball Mill measures 12″ x 12″ and has wellrounded corners. ... At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill. The Rod Mill Work Index (RWI) is used for particle size determination in a size range from 25 mm down to mm whereas Ball Mill Work ...
WhatsApp: +86 18838072829grams per revolution (Gbp) is the ball mill grindability. The ball mill work index, Wi (kWh/short ton) is calculated from the following equation (Bond 1961):1 The mill should be cleaned by either blowing air into it or wiping the interior with a cloth and or brush. The FC Bond ball mill is now ready for the next sample.
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).
WhatsApp: +86 18838072829The work index can either be measured in the laboratory (the Bond ball mill work index determination is a common example) or it can be calculated from the operating performance of a milling ...
WhatsApp: +86 18838072829Dear all, Have a good day! I am trying to determine ball mill work index for a very soft . If I follow bonds procedure to do experiment, not able to determine. The following is the data of ore sample. F80% = 2300mic Mesh of grind =300mic 300mic in feed = 47% In this case if the sample is gri ... Work index is as per plant operation data is 2 ...
WhatsApp: +86 18838072829The goal of this work is to create an equation to adjust a Bond ball mill work index from one P80 basis to another. The proposed model consists of two components, the variable coefficient that is ...
WhatsApp: +86 18838072829Ball Mill Work Index tests using crushed feed, and Standard Autogenous Grinding Design (SAGDesign) Tests, patented by Outokumpu. (See reference 8 below). The comparison of these results gives context to how the various measurements relate to each other and how they can be used to obtain an accurate design for the grinding mills required for
WhatsApp: +86 18838072829Laboratories reporting Bond ball mill work index test results are asked to include the fraction of the feed passing the closing screen size in their summary tables. This will allow the Levin B ...
WhatsApp: +86 18838072829Abstract The Frederick C. Bond has several grinding indices (ball, rod, abrasion), one of which has been a significant guide for ball mills. The Bond ball mill work index is an expression of the material's resistance to ground and a measure of the grinding efficiency.
WhatsApp: +86 18838072829i is the ball mill Bond's work index [kWh/sht]; P100 is the mesh size used to close the grinding circuit [ m]; gbp is the grindability index [g/rev]. It has been recently proposed gbpbe renamed as the Maxson index [14]. Walter Maxson led the first research in which gbp was named as the grindability index [1], and was also
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.
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