1 introduction 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 2006this index is widely used in the mineral industry for comparing the resistance of different materials to ball milling for estimating the energy
9 reporting test results 91 report the wet ball mill value to the nearest whole number note 3—this test furnishes valuable supplementary data pertaining to the quality of the aggregate portion of flexible base material the wet ball mill test is more reliable than the los angeles abrasion test in evaluating the quality of base
Aug 10 2020 ball mills are a special instrument used to break up hard solids into a fine powder they are similar to rock tumblers in that the instrument is a rotating container filled with heavy balls to grind the substance into powder ceramic material crystalline compounds and even some metals can be ground up using a ball
B is the composite of ef factors for ball milling rowland 1982 excluding ef3 spi the sag power index spi test starkey amp dobby 1996 uses a benchscale sag mill test to determine the specific energy of an industrial sag mill the test is operated in closed circuit and the time required to
Ball mill amp crushing machinery 868 likes 4 talking about this manufacturer of ball mill crushing equipment drying equipment mining equipment sand making line and cement
Ball mill work index adjustment the bond ball mill work index test requires the operator to select an appropriate screen size to close the test the procedure states that the closing screen size should be such that the product size of the test is the same as the expected product size of the operating
Bond ball mill index test jktech a bond ball mill work index may also be used in the simulation and optimisation of existing mills and the associated grinding circuits sample requirements a minimum of 8 kg of material crushed to nominally minus 10 mm is preferred jktech would stage crush the sample to minus 335 mm as required for the bond
Bond estimated the amount of wear in terms of kilograms per kwh based on the abrasion index a ie wet ball mill kg kwh 016a i0015 033 dry ball mill kg kwh 0023a i 05 replacement ball size rowland and kjos proposed the use of their equation for the determination of the initial and replacement media
Bond grindability index test ball mill a bond ball mill 12 x 12 of fabricated construction comes with electric motor and gear reducer drive digital counter jogging button to provide positioning of drum for loading and unloading emergency stop button 44 lb ball charge stand and receiving
Can be determined using the data generated by a conventional bond ball mill work index test m ib is not the bond ball work index m ic and m ih values are also provided as a standard output from a smc test morrell 2009 the general size reduction equation is as follows morrell 2004 b f x f x 2 1 i i 4 2 w m x x 1 1 where
Dec 04 2020 the laboratory procedure for running a bond ball mill work index test requires that the operator choose a closing screen sieve size the instruction
Dec 18 2013 for p80s finer than 75 μm 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
Feb 23 2021 the proposed flowsheet for the kon comminution circuit is a primary crusher followed by a sag mill ball mill and a pebble crusher the target grind is 80 passing
First a jar mill grindability test requires a 5 lb 2 kg sample and produces a direct measured specific energy net hphrt to grind from the design feed size to the required product size the second test a bond work index determination results in a specific energy value net hphrt from an empirical
In a 300 mm diameter mill this test has been further developed by starkey hindstrom and orser 2006 this test now includes a bond ball mill work index test the macpherson test is still being offered by some testing facilities this dry test requires at least 180 kg of
It is commonly known that one must run the bond ball mill work index test such you pick a closing mesh to give a p80 close to desired grind size this 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
Oct 15 2015 the bwi test is used extensively in the mining industry to analyse the absolute resistance of different materials to ball milling the energy consumption for ball milling and scale up the test itself contains 5 major components a standard grindability test of a material an empirical equation that converts the test results to the observed
Others in allischalmers have developed a grinding test in a ball mill in a closed cycle until the establishment of stable recirculating load maxson et al 1933 the bond work index is a parameter which represents a measure of an ore resistance to grinding numerically the work index represents the energy
Rod mill work index test for these purposes chose a o closing screen for the ball mill test one standard square root 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
Safety is a prime consideration for all alsto equipment and the bond index ball mill is supplied equipped with acoustic enclosure the ball mill is designed to accept a ball charge in accordance with f c bond’s standard this ball charge consists of 286 balls as follows 44 x 35mm balls 67 x 30mm balls 10 x 254mm balls 71 x 1905mm balls
Standard bond ball mill grindability test methodprocedure here 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
The ball mill abrasion bma test was developed by the university of queensland materials performance group to simulate the high stress abrasion conditions experienced in production ball
The ball mill work index laboratory test is conducted by grinding an ore sample prepared to 100 passing 336 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 material size of
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 this happens after 7–10 grinding cycles which shows that the procedure is a lengthy and complex one and is therefore susceptible to
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 335
The bond ball mill work index is one of the most commonly used grindability tests in mining and is often referred to as the bond work index the test is a lockedcycle test where ground product is removed from test cycles and replaced by fresh feed the test much achieve a steadystate before completion sample
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 characteristics of a material remain constant over all size ranges the calcul ated
The dm test has been based on the apparatus used for the texas ball mill test the test method involved the testing of four representative subsamples of about 35 kg each performance related results have shown that if the durability mill index dmi based on the product of the maximum plasticity index and the maximum p245 remains below 100
The mill is used primarily to lift the load medium and charge additional power is required to keep the mill rotating 813 power drawn by ball semiautogenous and autogenous mills a simplified picture of the mill load is shown in figure 83 ad this can be used to establish the essential features of a model for mill
The spi test in combination with bond ball mill data are used in the advanced comminution economic evaluation tool ceet grinding simulation system for design optimization and production forecasting studies the spi has the advantage of requiring a low sample weight and is therefore well suited for geometallurgical mapping of ore
This grindability test or bond ball mill work index procedure is used to determine the bond work index of minus six mesh or finer feed ore samples these equation application methods are used to process 12″ ore samples in a ball mill using a standard ball charge below describes in general terms the bond work index procedure used by a professional metallurgical testing laboratory if you
Torquemill test as in the example that follows torque mill solids load during test 1125 kg 248 lb of ball mill feed sample from plant survey sample is reconstituted with water to be the same percent solids as the plant ball mill discharge mill speed 352 rpm 65 percent of critical speed length of time of