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 3327 mm
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 10 kg of material crushed to nominally minus 10 mm is preferred
JKTech Laboratory Services Bond Ball Mill Index Test BRMWI A Bond Ball Mill Index Test BBMWI is a standard test for determining the Ball Mill Work Index of a sample of ore The BBMWI is a measure of the resistance of the material to crushing and grinding
Bond Ball Mill Laboratory Scrubbing testwork Batchlaboratoryscrubbingtestworkareconductedusinga scrubber having a diameter of 1 m The variable speed unit is Bond Rod Mill Point load test ThePointloadtestinghasbeenusedformany yearstodeterminerockstrengthingeotechnical neratedcanbeusedinvariability studiestoclassifyoresindifferentdomains
bond ball mill work index testwork providers bond ball mill work index testwork providers 11 Jun 2012 Gulin supply Mining and construction equipment for mineral handling The crushing screening washing
Charge Height Generally For overflow ball mills the charge should not exceed 45 of the mill volume For grate discharge mills the charge should occupy about 50 of the mill volume Bond developed a relationship that can be used to determine the percent charge by volume as a function of the vertical height above the charge He
However in this situation the ball mill has to supply this energy and it has a different higher work index than the crusher ie the ball mill is less energy efficient than a crusher and has to input more energy to do the same amount of size reduction Hence from equation 7 to crush to the ball mill circuit feed size x 2
For overflow ball mills the charge should not exceed 45 of the mill volume For grate discharge mills the charge should occupy about 50 of the mill volume Bond developed a relationship that can be used to determine the percent charge by volume as a function of the vertical height above the charge He and the radius of the mill R ie
The ball mill work index is con rmed at 16 kWht The operating work index though is in the range of 21 kWht to 25 kWht showing high inef ciency This raises the point that in some cases the Bond EF4 oversize factor calculation is not suf cient to compensate for the milling inef ciencies that arise
Because of the difficulty in determination of this index alternatives to the standard method have been developed by many researchers Vedat and Huseyin 2003 In the determination of ball mill work index 15 kg of representative ore at 100 335 mm is crushed to 100 335 mm Amtech 2006
The Bond Index conforming ball charge consists of 43 x 145 balls 67 x 117 balls 10 x 1 balls 71 x 075 balls 94 x 061 balls The optimum number of grinding balls is 285 However the ball diameters vary due to wear Therefore the total ball number should be adjusted from time to time to ensure a total mass of 20125 grams The grinding jar of the Bond Index Ball Mill measures 12 x 12 and has well
Measuring ore grindability in balls mills The Bond Ball Mill Work Index is a measure of the resistance of the material to grinding in a ball mill It can be used to determine the grinding power required for a given throughput of material under ball mill grinding conditions
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
2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALLMILL SCALEUP Ballmill scale up Bonds LawData zBond work index w i zFeed D f and product d size both 80 cumulative passing Result The specific grinding energy w Mill power draw P wT where T the mill capacity Mill dimensions from Tables or charts
The grindingproduct size P in a Bond ball mill which is given by the aperture size which passes 80 of the grinding product as a function of the aperture size of the test screen P k can be expressed by the formula P P k K 2
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 pan
Oct 15 2015 Bond Work Index BWI Hardgrove Grindability Index HGI tests for biomass coal BWI can predict the potential for mill choking of biomass in a tube and ball mill HGI is a poor method of predicting grindability of biomass in vertical spindle mills Pellets should be composed of predensified particles close to the target size
The basic parameters used in ball mill design power calculations rod mill or any tumbling mill sizing are material to be ground characteristics Bond Work Index bulk density specific density desired mill tonnage capacity DTPH operating solids or pulp density feed size as F80 and maximum chunk size product size as P80 and maximum and finally the type of circuit openclosed
The FC Bond ball Mill comes with table stand pictured motor clutch revolution counter motor starter and controls 12 machined steel drum 4412 pounds of steel balls Bond Index test receiving pan and hand screen pan
Use of Work Index Since its introduction in the 1960s the Bond Ball Mill Work Index BBMWi parameter has been extensively used in predicting ball mill power draw Along with comminution circuit design the work index parameter is widely used in tracking mill performance Due