1 comparative bond work index data were supplied by frank van der meer, evert lessing and ric stocco of weir minerals. hence the bond ball mill test should be modified when applied to the grindability of hpgr product. figure 1 shows the product of progressive crushing to 100 3.35 mm standard bond procedure and the product of a.
15022016 for p80s finer than 75 m, 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.
A modified bond ball mill procedure mod bond was developed by minnovex technologies now sgs which requires 1.2kg of sample crushed at minus 3.35mm. the 1.2kg 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.
Also includes the conduct of both the rwi and bond ball mill work index bwi tests on the same standard rock sample. the results of the comparative testing of rwi across seven laboratories around the world are shown in table 1. the standard deviation of the rwi measurements is 12.1 per cent compared.
Ball mill operation for further size reduction grinding. 2.3 procedure for the determination of work index using modified bonds method the modified bonds method for determining work index of an ore involves the use of reference ore of known grindability. experimental procedures were as follows 1.
Bond ball mill and grind for an arbitrary number of mill revolutions n 1 50, 100 or 150 revolutions. after grinding, screen the sample on the comparative sieve and determine.
Bond ball mill work index test 6 modified or comparative bond ball mill index 7 8 bond rod mill work index and bond low energy impact crushing work index 9 sagdesign test 10 smc test 11 jk dropweight test 12 point load index test sag power index test spir 13 mft test 14 fkt, skt, and sktws tests 15 geostatistics.
Bond work index for an ultrafine mill culturenature.eu. the bond ball mill work index is a measure of the resistance of the material to modified or comparative bond ball bond ball mill work index . .. hard in.
Comparative bond ball mill work index comparative bond ball mill work index 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 2006 this index is widely used in the mineral industry for comparing the resistance of.
Comparative bond test report zt640692mm1307 june 2019 final v1.0 page 2 2 test results testing was performed using the standard bond ball mill test methodology on a single blended sample or ore crushed to a feed size of 100 passing 3.35mm. a summary of the media specifications used for each test is given below in table 2.1.
Correlation between bond work index and . 3 standard bond tests the bonds standard ball mill is used to determine the work index value of differ ent samples. the bond work index is defined as the kilowatthours per short ton required to break from infinite size to a product size of 80 passing 100 m. if the breakage. capacity. th.
Determination of bond ball mill work index of limestone. modified or comparative bond ball mill cement stone crusher. the following modified bond equation was proposed for crushing magdalinovic, 1990 wc cp a wi cp 10 cf 10 8 where wc is energy consumed for clinker crushing kwht, wi is bond ball mill.
Gb bonds standard ball mill grindability, net grams p of ball mill product passing sieve size p 1 produced per mill revolution. the rest of the terms are defined as in equation 1. the work index obtained following the standard bond grindability test described above predicts the energy requirement for a 2.44 meter 8ft. inside liners.
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 for grinding, and for ball mill scaleup. the test has existed for more than 40 years man, 2002 .
Jk bond ball mill test since its introduction in the 1960s, the bond ball mill work index bbmwi parameter has been extensively used in predicting ball mill power draw. use of work index along with comminution circuit design the work index parameter is widely used in tracking mill performance. due to the age and lack of controls for the test,.
M. note thatin order for no correction factor for ball mill product fineness to applythe ball mill circuit p80 should be no less than approximately 70 m bond, 1962. this bond efficiency determination should not be applied to circuits with a p80 finer than approximately 70 m without making qualifications. 3.
Micrometers in size. according to the bond standard procedure, the work index is determined by simulating a dry grinding in a closed circuit in the bond ball mill to achieve 250 circulating load bond, 1949, 1952, 1961. the test is performed on a raw material approximately weighing 10 kg, which coarseness is 100 3.327 mm.
Modified bond index adetula yomi vincent, ozah blessing, alabi oladuni oyelola, john ade ajayi, equation called berry and bruce comparative bonds reference quartz to the ball mill and figure 2 is the graph plotted showing sieve sizes against cumulative percentage.
Modified or comparative bond ball mill cement stone crusher. ball mill index. index bond ball mill xsm. about xuanshi xsm is a professional manufacturer of grinding mills and stone crushers, such as gold mining equipment ball mill bond work index for limestone. save pdf core.
Modified or comparative bond ball mill index prestige grinders price screen crusher new zealand company nmdc kirandul screening plant second portable crusher for sale sa belt sander belt grinding machine.
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 screens of 75 m or finer are to be treated with caution. the bond work index relationship has been noted to apply down.
Samples were weighed for sieve analysis. the modified bonds method of determining the network index of ore involves use of reference ore of which grindability is known. the procedure is as follows. 1 100 g each of samples of the ore under test and the reference ore were crushed and pulverized in the laboratory mill machine for an hour,.
Size analysis of the ball mill feed and discharge for both the ores was carried time produced comparative results with choice of bonds were device. one of these methods was derived by 1. the determination of work index using modified bonds method can be compared to method of determining it by berry and bruce in 1966.this method.
Standard bond tests showed a reduction in the bond ball mill work index wi of the mineral sample used in this study when using relo grinding media. the modified bond test procedure is based on.
The ability to simulate the bond work index test also allows examination of truncated ball mill feed size distributions on the work index. for grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill see figure 3.10, a question arises as to whether this practice will alter the ball mill work index bw i of the.
The ball mill grindability of ores is generally determined by the bond standard grindability index test method. however, this test and procedure is not applicable to fine materials such as sands the grindability of fine materials must therefore be determined by a comparative grinding method, for which a reference material of know grindability is required.
The ball mill work index laboratory test is conducted by grinding an ore sample prepared to 100 passing 3.36 mm 6 mesh to product size in the range of 45150 m 325100 mesh, thus determining the ball mill work index wi b or bwi. the work index calculations across a narrow size range are conducted using the appropriate laboratory work index determination for the.
The 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 100 passing size of 3.35 mm.
The bond ball mill work index data metric obtained by macpherson a.r. macpherson consultants ltd., 1994 for placer were 15.3 for csb and 10.5 for clb. alternative approaches for determination of bond work index on these studies were carried out in a standard ball mill 300 mm x 300 mm size. the grinding.
The bond ball mill work index test has been used for ore hardness characterization for more than 80 years. nevertheless, the test suffers from significant disadvantages when compared with other characterization methods. it is expensive, labour.