work index ball mill

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 It is a locked cycle test conducted in closed circuit with a laboratory screen

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 mm Any screen size below 600µm can be used for the testwork depending on your requirements

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

Ball mill design requires a Bond work index BWi for ball mills at the correct passing size SAG mill design requires an appropriate SAG test for example SPI Chapter 5 Flotation design needs a valid measure of kinetics for each sample including the maximum attainable recovery and rate constants for each mineral Chapter 12

According to the Bond standard procedure the work index is determined by simulating a dry grinding i n a closed circuit in the Bond ball mill to achieve 250 circulating load Bond 1949 1952

The standard Bond Ball Mill Work Index test procedure is firstly to stage crush the feed to minus 335mm and size a representative sample The test then involves a series of batch grinds in a standard Bond mill A Bond mill is 0305m by 0305m with rounded corners a smooth lining and runs at 70rpm

The test requires calibration against the standard Bond Ball Mill Work Index test to estimate the Work Index It is used to show the orebody hardness profile and to predict throughput in a ball mill circuit SGS created the Modbond grindability test and has a large proprietary database

The Bond’s BallMill Work Index is a measure of the resistance of the material to grinding in a ball mill This Index is widely used in the industry for comparing the resistance of different materials to ball milling for estimating the energy required for grinding and for ball mill scaleup

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 21 mm whereas Ball Mill Work Index BWI is used for the range from 21 mm down to 100 µm Adjustment of grinding parameters

Bond Ball Mill Work Index Determination The average useful work input to the standard ball mill is 65 joulesRev with 115 joulesRev to the rod mill The crack energy Ce of the sample tested is found by dividing joulesRev by CmRev The standard work index can then be found by transposing Eq 16 and solving for Wi100

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 QUICK METHOD FOR BOND WORK

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

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 procedural errors

Operating work indices can be used to evaluate individual units in a conventional circuit or the overall performance of an autogenoussemiautogenous AGSAGball mill circuit but they are of limited value in evaluating AGSAG and ball mill sections separately This problem arises due to the difficulty of

The Bond lowenergy impact crushing work index more informally the Bond crushing work index is not as common as the Bond ball mill work index and it is a notoriously noisy test The test is a perspecimen test where individual specimens of prepared rock are handpicked by

22 Ball Mill Batch Process The mill dimensions D × L are 0204 × 0158 m and it is loaded with 65 kg steel balls between 25 and 32 mm in diameter The mill rotates on rolls and its frequency is set to 70 RPM 1667 Hertz corresponding to 85 of the critical frequency The mill power is P 162 Watts

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 µm If the breakage characteristics of a material remain constant over all size ranges the calcul ated work

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

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 •

Bond Work Index Procedure and Method Mineral 20190626 This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Address No 169 Scientific Avenue National HighTech Industrial Development Zone Zhengzhou

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 grindability well in advance of when ore are actually mined