Internationally accepted mineral metallurgical standard test procedures to determine the physical properties of ores include the Bond ball mill work index. This is empirical index determined by closed circuit grindability tests developed by F.C.Bond in the mid 1930s. It requires a specific 305mm diameter x 305mm long (inside dimensions) horizontal axis ball mill without lifters operating at 70 rpm to perform
The Bond Index conforming ball charge consists of 43 x 1.45 balls 67 x 1.17 balls 10 x 1 balls 71 x 0.75 balls 94 x 0.61 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 20.125 grams. The grinding jar of the Bond Index Ball Mill measures 12 x 12 and has well
Dec 07, 2018 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 if
Dec 07, 2018 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
The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined 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 stage-crushed to 100% passing size of 3.35 mm.
2017-1-7 The Work Index is used when determining the size of the mill and grinding power required to produce the required ore throughput in a ball mill. 2. Procedure 2.1. Bond Ball Mill Grindability The sample was crushed to 100% passing 6 mesh (3.35mm), from this a 700 cc volume was measured and weighed to be used as feed for the Bond Mill.
the rod mill and the ball mill. The simplified test method described in this paper is an alternative procedure to the ball mill grindability test. The work index is computed using the following empirical equation revised by Bond in 1960, where the sieve opening at which the test is made, (microns) 358 (2)
The Bond work index, W i , is defined in a Bond ball mill on the samples of standard size 3.327 0 mm. In practice, it is possible to find materials of non-standard size that are finer than 3.327 mm. In this work, a procedure for the calculation of
bond index calculation mill efficiency. rod mill work index has not been de ned as yet. The ball mill work index is con rmed at 16 kWh/t. The operating work index, though, is in the range of 21 kWh/t to 25 kWh/t showing high inef ciency.
Essa Bond Test-Work Equipment. 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 F.C.Bond in the mid 1930s.
Bond/Barratt Specific Energy Consumption SABC Model. This is a SAG or AG mill plus ball mill model that estimates the overall circuit specific energy consumption using the classical Bond work index equation for multi-stage crushing and single-stage ball milling (E ssbm) including Rowland efficiency factors.The circuit E total is equal to the E ssbm plus an inefficiency factor (CF) related to ...
Correction of Bond Ball Mill Work Index Test for Closing Mesh Sizes It is commonly known that one must run the Bond ball mill work index test such you pick a
SMC Data Processing. The results from conducting the SMC Test are used to determine the drop-weight index (DWi) which is a measure of the strength of the rock as well as the comminution indices Mia, Mih and Mic. In conjunction with the Bond ball mill work index they can be used to accurately predict the overall specific energy requirements 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 ...
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 closing screens of 75 m or finer are to be treated with caution. The Bond Work Index relationship has been noted to apply down
Jul 30, 2020 A Bond Ball Mill Work Index may also be used in the simulation and optimisation of existing mill(s) and the associated grinding circuit(s). 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 3.35 mm, as required for the Bond Ball Mill Work Index test feed.
micrometers in size. 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% -3.327 mm.
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 is to choose a sieve size that results in the ...
on Fred Bonds Ball Mill Grindability Work Index (BWi) testing methods. After the tests were completed, statistical analysis using the Q test, p values, the F test and the student t test were used
Bond Index Ball Mill Rod Mill Bt 100 Xl Retsch. The grinding jar for the bond index rod mill is 12 x 24 in size and has a waveshaped design 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
2.2. Bond Ball Mill (BBM) Standard Test The procedures to carry out the Bond grindability tests in ball mills and rod mills are outlined in Sections 2.2 and 2.3.
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.
should be noted that in the Bond standard approach, the ball milling work index has the largest influence. For a P 80 of 100 m, the ball milling work index accounts for approximately 70% of the weighting in the Bond standard calculation (GMG, 2015),
This ball mill, also called mill for measuring bond work index, is a key device for measuring grinding work index. It is widely used by teaching and researching departments for grindability test of ores raw materials for cement and its mixtures.
May 01, 2021 The Bond grindability test is performed in a standard Bond ball mill, dimensions DxL305x305 mm and a speed revolution of 70 min 1. The mill is filled with balls with a diameter of 15.5 to 30.6 mm, and has a total weight of 20.125 kg.
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 kilowatt-hours 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 ...
Table I shows the Bond ball mill work index obtained for the ore samples as well as the iron and silica content in concentrate and tail after LIMS. The concentrate weight recovery was in the order of 5060%. Furthermore it may be observed that the Bond ball mill work indices for
bond mill for grinding china traydryer. labtech 3 Index Ball Mill Grinding Mill China. labtech 3 Index Ball Mill 49 6938 Ratings The limingIndex Bond Mill Of. more 3 bond ball mill apcivilsupplies.co. Procedure for Determination of Ball Bond Work The work index is determined from feed crushed to 3.
the different faces of quarry, Bond work index of limestone Face4A results less than 20kwh/t, remaining 6 samples are marked as hard - rock because of high energy consumption and low grindability rate. Index Terms Ball mill, Bond Work Index, Comminution, Grindability, Liberation, Limestone, Ultra
The Bond Ball Mill Grindability Test is a locked-cycle laboratory grinding test. It provides the Bond Ball Mill Work Index which expresses the resistance of a material to ball milling. This Index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required for grinding, and for ball mill scale-up.
2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALL-MILL SCALEUP Ball-mill scale up (Bonds Law)Data 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)
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