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
Get PriceThe 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 the test operator and placed into the apparatus
It is a locked cycle test conducted in closed circuit with a laboratory screen sample requirements a minimum of 20 kg of material crushed to nominally minus 19 mm is preferred jktech would stage crush the sample to minus 125 mm as required for the bond rod mill work index test feed
Mill ball mill closed circuit crushing to 16 mm open circuit 8 dia rod mill to 1 mm closed circuit 8 dia ball mill to p80 um the ore test work index circuit operating work index 9 the standard bond circuit coarse ore bins fine ore bins screen crushing screen classification rod mill ball mill this is the reference basis for all work
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 product is t
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 kwhsht
For every bond ball mill work index test carried out at jktech a standard report is issued the report details the bond test procedure method and presents the results including f80 p80 grindability and work index further interpretation of the results is available if required frequently asked questions bond ball mill work index
Kinetic grinding test approach to estimate the ball mill work index 343 the w i parameter is obtained from bonds ball mill grindability test bond 1961 this test is performed according to the standard bond procedure which proposed model is presented in eq 1 this standard grindability test
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
Ball mill bond work index wib 121 kwhst rod mill bond work index wir 105 kwhst impact bond impact index wii 79 kwhst sag power mei online bond work index an abreviated test that did not reach steady state as a bond work index does would only be mill sizing etc
In a closed circuit dry grinding environment the ground product for the laboratory sag mill is then submitted to the bond ball mill work index test the number of sag mill revolutions required to grind the material to a p 80 of 17 mm is used to predict agsag specific energy using quation 4 correction e
An alternative approach to determine the effect of closing screen size on the bond ball mill work index bw i in the absence of extensive test work is to use computer simulation the batch grinding process has been modelled using the sizemass balance approach austin 37 chapter 11 and if we can do this then we can effectively simulate the bond ball mill work index test
Eng correction of bond ball mill work index test for closing mesh sizes yardin josefin norman b keevil institute of mining engineering university of british columbia canada and alex doll sagmilling canada
Use a 1190 181m screen to close the rod mill wi test for these purposes choose a closing screen for the ball mill test that is one standard square root of 2 series mesh size coarser than the plant ball mill circuit p80 if choosing between two standard mesh sizes choose the finer one
A total of 221 variability samples from the lac otelnuk deposit were submitted for a grindability characterization study which involved the spi174 and the modified bond ball mill grindability mod bond tests standard bond ball mill grindability test and spt
Results of bond ball mill tests conducted with closing screens of 75 181m or finer are to be treated with caution the bond work index relationship has been noted to apply down to approximately 70 m and perhaps no finer181 without making qualifications
The test requires at least 10 particles of 75 50 mm ore however for more representative results it is recommended that over 20 particles are tested bond ball mill grindability test the bond ball mill work index bbwi test is carried out in a standardised ball mill with a
Bond ball mill grindability test the test determines the bond ball mill work index which is used with bonds third theory of comminution to calculate net power requirements various correction factors may have to be applied w wi 10p 10f where w net power consumption in kwht
Oct 18 2018nbsp018332celtest have the capability to carry out the bond work index bwi test in accordance with epri report cs3612 fgd chemistry and analytical method handbook volume 2 the bwi is used to estimate the required mill power per ton of product
Standard bond ball mill grindability test methodprocedure 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
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 bonds 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 and
In this regard calculation of work index of limestone made by standard bond grindability test ball mill was employed to conduct the grinding test of seven different samples among all seven samples collected from the different faces of quarry bond work index of limestone face4a results less than 20kwht remaining 6 samples are marked as hard
The bond ball mill work index bbwi is the industry standard procedure for assessing the grindability hpgr lockedcycle test with a closing screen of 335 mm although the 80 passing sizes are similar and although rowland and kjos 1980 developed many correction factors none of these relate to the degree of fines in the feed
A number of samples were taken from the sag mill feed belt and subjected to smc tests and bond ball mill work index tests note that the bond tests were conducted using 150 microns as the closing screen size so that the final product size from the tests was similar to
Puritic ore calculated bond work index is higher with different circulating loads the bond work index is higher with lower circulating loads the purpose of this study to determine the effects of circulating load cl and test sieve size p on the bond ball mill grindability ght and work index w with natural amorphous silica
Nov 12 2019nbsp018332bond ball mill work index test and result a single ball mill grindability test was performed on a 12 kg subsample of the north lake master composite to determine the bwi number a closing screen
Oct 24 2018nbsp018332the work index can either be measured in the laboratory the bond ball mill work index determination is a common example or it can be calculated from the operating performance of
Standard size ranges and the related bond work indexes feed size f 80 m product size p 80 m work index 100000 10000 crushing cwi 10000 2100 rod milling rwi 2100 100 ball milling bwi fig 1 laboratory equipment used by rivs for determining the 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 the test much achieve a steadystate before completion sample requirements
Testwork bond rod mill work index testwork bond rod mill work index test name bond rod mill work index abbreviation alternate forms wi rm rwi typical f 80 size typical p 80 size 11 000 181m 900 181m models bond models 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 apparatus
Oct 15 2015nbsp018332bond work index bwi amp hardgrove grindability index hgi tests for biomass amp 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