Numerically, the work index is the energy required in kwh/t 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.
Laboratory Rod / Ball Mills including Bond Rod / Ball Work / Grindability Index. MARC manufactures a wide range of laboratory metallurgical ball / rod mills and automated Bond rod / ball mills (with wave liners) to suit most metallurgical laboratory applications. Our range extends from small 6L jar-type mills that are manually positioned on ...
XMGQΦ305 Grinding Work Index Ball (Rod) Mill . Description; XMGQΦ305 Grinding Bond Ball (Rod) Mill is mainly applied for testing the grinding work index of the material of every kinds of ores, slag, etc. Under the specific rotation speed for dry grinding, …
This video was put together by Joshua Wright and Aldo Vasquerizo as a supplemental lecture for University of Nevada Reno.If you have any questions, need advi...
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 passing size of <3.35 mm.
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 ...
In 2014, the Bond Variability Test (BVT) was developed and introduced. Similar to the SVT, the BVT is an abbreviated version of the Bond Ball Mill Work Index test, providing direct measurement of the ball mill hardness in kWh/t.
WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index (kWh/t) WioACT Actual Operating Bond Work Index determined from measurements on the circuit (kWh/t) WiRM Bond Rod Mill Test Work Index (kWh/t) WiSTD Standard Circuit Bond Work Index (expected or designed) used for circuit design. Specific energy requirement at ...
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 -3.327 mm.
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.
Bond ball mill work index; Bond rod mill work index; Bond crushing (low-energy impact) work index; Formulae. Rowland, 2006. where CF is an optional calibration factor, use 1.0 for normal situations. The rod mill oversize feed factor (EF 4 RM) is calculated using the greater of the sample's rod mill or crushing work index (which is usually the ...
FIGURE 6: BOND BALL MILL WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS (MPa) 5 10 15 20 25 30 WiBM (metric) Figure 6 displays the plot of ball mill Work Index (Wi BM) versus UCS. Still no relationship is observed.
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 1930's.
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 µm or finer are to be treated with caution. The Bond Work Index relationship has been noted to apply down
Ball Mill Design/Power Calculation. 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
Bond ball mill and grind for an arbitrary number of mill revolutions (N 1 = 50, 100 or 150 revolutions). After grinding, screen the sample on the comparative sieve and determine
The reason for this variation in ball mill work index is because the ore at Mt. Milligan has an intrinsic exponent of –0.45 in the 100 µm to 200 µm size range, not the –0.50 exponent empirically measured by F. Bond. The work index increase between 100 µm and 76 µm is due to a porphyritic grain size that causes a spike in energy
Bond ball mill work index; Required parameters. F 80, µm is the 80% passing size of the fresh feed to the circuit (expected to be a Bond-compatible size distribution). P 80, µm is the 80% passing size of the circuit product (expected to be a Bond-compatible size distribution).
The Bond Work Index (BWI or W i) is defined as the calculated specific energy (kW h/t) applied in reducing material of infinite particle size to 80% passing 100 μm . The higher the value for W i, the more energy is required to grind a material in a ball mill, .
The SAG mill pinion energy, W SDT (kWh/t) and SAG discharge Bond ball mill work index, S d-BWI (kWh/t), are then used to calculate the total energy to grind the ore from 80% passing 152 mm to 80% passing the client specified final product size P 80.This information, along with the ore specific gravity, is used to calculate necessary mill sizes and motor power in industrial applications.
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.
The drum of the ball mill (Pic. 1) is a hollow cylinder of steel, lined inside with armor lining plates which protect it from impact and friction effects of the balls and the grinding material. The shape of drum liners has a significant impact on mill's work. Drum Liners of ball mills operated on a large source material have ribs.
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 …
Abstract The Bond work index, Wi, 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 …
Ball Mill Design/Power Calculation. 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 . get price
In particular, the Bond work index (wi) is considered a critical parameter at an industrial scale, provided that power consumption in comminution operations accounts for up to 40% of operational costs. Despite this, the variability of wi when performing the ball mill Bond's standard test …
The ball mill and spiral classifier work together, to be a close circuit grinding system, to control the materials to be grinded as you want.More details ple...
The Bond work index (Bond, 1960) is based on Bonds law, which states that the energy consumed is proportional to the 1.5 power of particle size rather than the square of Rittingers law. Accordingly, the energy consumed in reducing the particle size from xF to …
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 shaking in a 1000cc graduated cylinder and the weight of 700 cc is placed in the mill and ground dry at 250 ...