Our Testing Laboratory in Osh, Kyrgyzstan More Services The grinding circuit is among your largest capital investments and greatest operating costs. SGS can reduce your risk by combining different test procedures and design methodologies to ensure that you optimize this critical part of your plant.
WhatsApp: +86 18838072829The ball mill work index is shown below. BM Wi (kWhr/st) = BM Wi (kWhr/mt) = Bond Ball Mill
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 18838072829The test is a standardized methodology that ends when a circulating load of 250% is obtained. In this paper, a new method based on the Population Balance Model (PBM) is proposed and validated to estimate the results of the Bond ball mill work index test (Wi B). The model presented in this study combines the first cycle of the Work Index test ...
WhatsApp: +86 18838072829Here is the old AllisChalmers 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. It is screen analyzed and packed by shaking in a 1000cc graduated cylinder, and the weight of 700 cc is placed in the mill and ground dry at 250 ...
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 18838072829The Bond Ball Mill Work Index (Wi) is one such spatial estimate which remains difficult to infer correctly. The Wi defines the specific energy (kWh/ton) required in grinding a ton of ore in the ball mill from a very large size (infinite) to 100 m (Lynch et al. Citation 2015). At the time of writing, this variable is of particular interest for ...
WhatsApp: +86 18838072829As such Bond ball mill work index alone is not an effective basis to estimate the comminution energy requirements for many of Newmonts operations. Figure 1 Newmont sites on the Bond intensity energy curve, comparing the BWi The position of the sites on the Bond operating work index (OWi) energy curve is presented in Figure 2. What is
WhatsApp: +86 18838072829The Bond Ball Mill Grindability Test (Bond, 1952, 1961) gives the Bond Ball Mill Work Index. This Index expresses the resistance of a material to ball milling; the higher the value of the Bond Ball Mill Work Index, the more difficult it is to grind the material using a ball mill. This Index is widely used in the mineral industry for:
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 ...
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 Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a predefined 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 stagecrushed to passing size of < mm.
WhatsApp: +86 18838072829world. It shows that the ball mill work index is normally distributed with an average of and a median of kWh/t. bOnd rOd mill GrindAbility The Bond Rod Mill Grindability Test is performed similarly to the ball mill test. The feed sample is stagecrushed to ½" and the test is run under a circulating load. As in the ball mill ...
WhatsApp: +86 18838072829For the ball mill grindability test, the work index is calculated from the following revised equation (in short tons): where: Pi = sieve size tested (microns) Gpb = ball mill grind ability Wi, P F have the same meanings as in the top equation. Equipment required: Laboratory ball mill, cm x cm with following ball charge: Agitator ...
WhatsApp: +86 18838072829Standard Bond ball mill grindability tests and calibrated Mod Bonds, using a closing screen of 270 mesh (53 microns), classified most samples as medium to moderately hard and averaged kWh/t (Mod Bond only). The SPT lockedcycle high pressure indices (HPi) ranged from kWh/t to kWh/t averaging kWh/t.
WhatsApp: +86 18838072829Standard Bond tests showed a reduction in the Bond ball mill work index (w i) of the mineral sample used in this study when using Relo grinding media. The modified Bond test procedure is based on using the standard Bond ball work index test but changing the circulating loads (350%, 250%, 150%, ). The comparative tests with RGM were carried ...
WhatsApp: +86 18838072829Abstract The 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 ball milling.
WhatsApp: +86 18838072829This paper examines potential relationships between UCS and Bond Work Index values (crushing, rod mill and ball mill). Data from 11 mines located around the world is analysed for correlations between UCS and various Wi values. Introduction Need to accurately predict future mine and mill production rates requires a knowledge of ore
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 18838072829The Bond Ball Mill is a small universal laboratory mill used in calculating the grindability of ... (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
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.
WhatsApp: +86 18838072829In the Bond ball mill test, the work index is finally obtained. by. w. P Gbp PF. i = ... This was done by means of the Bond Ball Mill Standard test [24][25] [26]. In brief, with the aim to ...
WhatsApp: +86 18838072829Average grinding work index (Wi) by type of mate rial, according to Bond (see table ): The work index (Wi) expresses the kWh required to reduce a short ton of material from theoretically infinite feed size to 80 % passing a square screen opening of 100 microns. The work index values apply to ball mills grinding wet in closed circuit.
WhatsApp: +86 18838072829Conclusions. The power model and linear model both will give reasonable P80 estimates given the P100 of a Bond ball mill work index test product. The power model might be marginally more robust ...
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 18838072829Research was performed to make an objective comparison of Bond Ball Mill Grindability Work Index results derived from using two commercial testing apparatus, from BICO and Sepor respectively, each ...
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 18838072829The Bond ball mill test is used to determine the socalled standard work index, which is defined as the specific energy consumption (in kWh/t) required to reduce a material from a notional ...
WhatsApp: +86 18838072829