Generally Bond work index is a common method for selecting comminution equipment as well as estimation of grinding efficiency and calculating required power In the current research a simple fast and accurate procedure is introduced to find the
Bond work index for rod mill product image introduction the bond work index for ball mill is a special equipment for testing bond ball mill work index simple lab test can choose ball mill by power method or judge the effects of material properties change to the ball milling process or the operation condition of crusher by using this
Bond had used short tons to determine work index to convert to metric tons the factor 11 has been used here 62 11 682 2 w i conforms to the motor output on an average overflow rod mill of 244 m internal diameter wet grinding in open circuit
Internationally accepted mineral metallurgical standard test procedures to determine the physical properties of ores include the bond ball mill work index and the bond rod mill work index these are empirical indices determined by close circuit grindability tests developed by fcbond in the mid 1930s
1 the ore fed to a rod mill has a bond work index of 18 kwht1 the p80 of feed to the mill is 22 mm f and the p80 of the product from the mill is 0140 mm p calculate the work in kwtonne required to grind the ore to the product size 2a ball mill with an internal diameter of 2600 mm is operated at 75 of the critical speed
The mill power is 225 watts calculated by 6 fi p nally the product is wet screened to find the size d80 24 rod mill semi continuous process the same mill is used for the semi continuous grinding tests which is similar to the bond test but with the exist ing mill of known power after time the mill
Particle size are calculated and the bond ball work index is then calculated using the standard bond ball work index formula 445 023 082 10 80 10 80 2 where w i represents the bond ball work index f 80 and p 80 are the feed and product particle sizes
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 work
The model was validated for four materials showing that it can predict the bond rod mill work index with deviations below 10 requiring only 153kg of sample the procedure is demonstrated to
The bond rod mill work index is used to calculate the power requirement to grind from to about 14 mesh the test has been mainly used for the design of rod mills or primary ball mills but it can also be used along with the other bond tests bwi and cwi for sag mill design
Determination of the work index for ball and rod mills in 1952 and modified it in 1961 the standard bond ball mill grindability test is a closed circuit dry grinding test with a 250 circulating load the standard procedural outline of the test is stated in bond 1961 the work index for a ball mill wi is then calculated from the following
Bond rod index mill 12 x 24 consisting of a one 1 piece cast shell complete with integral wave 1 hp 360220 volt motorgear reducer drive support frame which allows the mill to tilt 5 degrees during operation and 45 degrees for discharge manual operation receiving pan rod charge and control panel complete with digital revolution counter startstop buttons and emergency
An ore fed to a rod mill has a bond work index of 140 kwhrt1the p80 of feed to the mill averages 250 centimetres and the p80 of the product from the mill is 0104 millimetresa calculate the work required to grind the ore to the product sizeb calculate the reduction ratio
Jan 02 2013 titan bond work index rod mill titan process equipment ltd the titan bond work index rod mill is onepiece cast construction with integral wave liners of a form described by bondthis mill is used to perform the necessary more detailed
Here is a list presented in table form of rod mill work index as testedpresented by sme handbook of mineral processing nl weiss editor ny 1985
Rod mill power is dependent on mill capacity and work index mill power increases with increasing rod charge increasing mill speed increasing mill length rowland and kjos 1980 provided an expression to quantify power draw at the pinion shaft per unit mass of rods p m
Bond ball mill work index bwi kwht 134 bond rod mill work index rwi kwht 181 table 1 example of agsag ball mill circuit wio calculations 1 2 abstract optimum use of power in grinding both in terms of grinding efficiency and use of installed capital can have a large effect on profitability
The fc bond work index test ball mill was designed by f c bond for use in determining the bond index a measure of grindability and power required for grinding applications the fc bond mills are used in laboratories throughout the world a copy of fred c bonds method of crushing and grinding for determination of the bond index is included with each mill
Oct 24 2018 the work index is a fitted coefficient to bonds equation given in the picture above the bond ball mill work index determination is a common example rod mill wi april 26 2020
Bond f c crushing tests by pressure and impact trans aime vol 169 1947 pp 5866 bond rod mill grindability test the test determines the bond rod mill work index which is used with bonds third theory of comminution to calculate net power requirements when sizing ball mills various correction factors may have to be applied
Jan 01 2013 to calculate bond rodmill work indices the four samples were screened and the particle size distributions plotted in fig 2the plot was used to find f 80 of the samples for calculations fig 3 fig 4 show the grinding kinetics of pb cu fe and mn ores in the bond rodmill in different testsieves the slopes of all lines in the figures are equal to the k value of eq
Generally bond work index is a common method for selecting comminution equipment as well as estimation of grinding efficiency and calculating required power in the current research a simple fas
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
Bond work index value of these components mixtures is greater than the bond work index of harder components clinker oner 2000 have conducted a research of clinker and blast furnace slag mixture bond work index in different mass proportions he found out that these values are always lower than the bond index obtained
Thus the work index of the blend will be weighted towards the harder components 39 figure 316 shows the bond work index of a blend of hard and soft ores as a function of the volume fraction of the softer ore in the blend the dotted line between the two extremes indicates the weighted average work index based on volume fraction
Figure 5 bond rod mill work index v unconfined compressive strength 0 100 200 300 400 ucs mpa 5 10 15 20 25 30 35 wirm metric the lack of fit observed relating the crushing work index was expected to carry over to the other bond work indices figure 5 displays the plot of rod mill work index wi rm versus ucs these
The bond rod mill work index is not as common as the bond ball mill work index and there are two different variations on the mill apparatusthe sagmillingcom models expect a mill with a wave liner and is not compatible with mills using smooth liners
Numerically the work index is the energy required in kwht to reduce a given material from theoretically infinite feed size to 80 passing 100 microns the work index of a particular material is determined in the laboratory by conducting the standard bond grindability test bond developed separate tests for the rod mill and the ball mill
For comparing the standard bond rodmill work index and the new modeled method work read more bate ssa a4 feb12layout 1 saimm approaches eg the bond work index would the design of ball and rod mill circuits and was that for the size ranges typical of ball mills the energy per
Determining the bond work index is a standardized method for characterizing the comminution performance of mineral samples cemtec uses this method for designing rod and ball mills the comminution performance is just like the desired comminution step and the production capacity crucial for determining the required mill size
The goal of this work is to create an equation to adjust a bond ball mill work index from one p 80 basis to another the proposed model consists of two components the variable coefficient that is determined from a specific work index determination and a fixed exponent determined by a calibration procedure