The ball mill work index laboratory test is conducted by grinding an ore sample prepared to passing 3.36 mm (6 mesh) to product size in the range of 45-150 µm (325-100 mesh), thus determining the ball mill work index ( WiB or BWi ).
The 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 a milling ...
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. The simplified test method described in this paper is an alternative procedure to the ball mill grindability test.
Test data from the Bond ball mill work index test is used to calculate the fine grinding index (M ib). The M ia and M ib indices are used to calculate specific energy for the coarse (W a) and fine (W b) components of the total grinding specific energy at the pinion (W T) according to Equation 7. W i = 4.K.M i.[Pf(P)-Ff(F)] (6) W T = W
The Bond work index (BWI) is a well-known method used when selecting comminution equipment, to evaluate the grinding efficiency and to calculate the required grinding power.
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, then screening the products, weighing, repeat operation several times, getting the grinding work index kWh/t. Technical Parameters:
C) for coarse rocks (75-50 mm), a rod mill work index (Wi RM) for intermediate sized particles (25-3 mm), and a ball mill work index (Wi BM) for small particles (<3 mm) (Ammtec, 2000). Laboratory testwork is required to determine these Work Indices, and each test requires carefully collected samples of rock that is representative of future mill ...
of the cyclone underflow back to SAG mill, introduction of a second classification stage as well as introduction of a second ball mill. The evaluation of breakage tests and survey data revealed the following; the Bond work index obtained for the current ore ranges between 17.20 - …
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.
The Bond grindability testing procedure has been standardized to obtain the same grindability values, i.e., Bond work index (BWi), on the same ore when tests are performed in different laboratories or by different operators. This is accomplished by the standardization of mill dimensions, tumbling speed, grinding-ball charge weight and distribution, sample charge …
A Bond Work index mill ball charge and closing screen product size distributions for grinding crystalline grains Int. J. Miner. Process., 165 ( 2017 ), pp. 8 - 14, 10.1016/j.minpro.2017.05.011
Wi Bond Work Index Ws Specific energy correction for size distribution (kWh/t) WiBM Bond Ball Mill Test Work Index (kWh/t) 3. KEYWORDS Autogenous Grinding (AG), Ball mill, Bond Work Index (Wi), Comminution circuit, High Pressure Grinding Rolls (HPGRs), Rod mill, Semi-Autogenous Grinding (SAG), Spe-cific energy (W) 4. INTRODUCTION AND BACKGROUND
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...
Bond Ball Mill Work Index. GTEK Bond Ball Mill Work Index is used for determine the grindability of materials, and help to choose the most suitable type and model of grinding equipment. Ask For Quote Donwload. Find more details in the options below. Photo.
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 …
published his method of energy calculation with an index called Bond work index (Bond 1961). In the 1970s, the population balance or selection and breakage function model was at the forefront of research (Fuerstenau et al. 1973). A number of advancements were made in the application of this model to ball mill grinding.
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 non-standard size that are finer than …
work index values tend to remain the same for different product sizes. As a supplement to this study, rod and ball mill grindability tests were run on the porphyry copper ore at sizes of 4 through 65 mesh for the rod mill tests and 14 through 325 mesh for the ball mill tests. These tests were run to determine the changes in work index values,
Work index can change as a function of the product size of a Bond ball mill grindability test, which is controlled by the closing mesh size …
After which, the ore was grinded in a ball mill until a 250% circulating load was achieved. The Bond work index was then calculated to be equal to 41.38 kWh/tone. I. Introduction Comminution is the process of reducing particle size by breaking, crushing and grinding until the valuable minerals are minute enough and can be isolated by such ...
Work Index Ball Mill, alluding to the grind ability list of Metals, is utilized to demonstrate the granulating trouble of the material. It is measured by a rule that to compute the work file ball plant in light of yield of every unrest of the factory after the material is ground to an adjusted state by the predetermined plan.
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 ...
work indices for the AG/SAG mill and ball mill can be re-organised as [7] and [8], where B'Wio and A'Wio are the corrected operating work indices and WAG/SAG, WBM are the respective power draw of AG/SAG and ball mills. Note that the ball mill operating work index is applied only on the portion that needs the additional grinding (Q2),
Ball Mill Wio, BWio 86 Circuit Wio, OWio 146 Bond Ball Mill Work Index, BWi, kWh/t 134 Bond Rod Mill Work Index, RWi, kWh/t 181 Table 1 Example of AG/SAG 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 .
The Bond's 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 µm. If the breakage characteristics of a material remain constant over all size ranges, the calcul ated work
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.
Bond ball mill work index. The method requires all the elements of the ball mill work index test to be filled in: Ball mill Wi test closing screen size, umclosing, µm; Ball mill Wi test product size, P 80, µm; Ball mill Wi test feed size, F 80, µm; Ball mill Wi grams per revolution at test conclusion, gpr; Required parameters
The aim of this study was to develop a new method for assessing the Bond work index in a ball mill (BBWI), which is based on a first order kinetics present in the Bond ball mill for grinding mineral raw materials (Austin et al., 1981; Ahmadi and Shahsavari, 2009). Theoretical basis of quick procedure
The Bond Ball Mill Work Index remains today as the only tool used for ball mill scale-up design. For an (only nominally, not at all materially modified) update on its use for industrial mill sizing, see " Selection of Rod Mills, Ball Mills, Pebble Mills, and Regrind Mills," Rowland, C. A., Jr., 1982, Chapter 23, Design and Installation of ...
For P80s finer than 75 μm, the Levin test, a modified Bond ball mill work index test, may be used to predict grinding performance. Signature Plots. No general work index formula governing energy use over a range of conditions, like the Bond equation for intermediate grinding, has yet been found for the fine grinding regime.
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 closing mesh to give a P80 close to desired grind size.
2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal WiSTD= –––––––––––– (3) 10 10 (––––-––––) √ ̄P80 √ ̄F80 The Bond Standard Circuit is the "conventional" crush-ing-rod-ball …
4.4.2 Bond Ball Mill Work index Results: Wi=25.23 kwh/t Reduction ratio is 2.98 Analysis: The sub-samples were compared to determine BWi (Bond Work Index) for unknown sample. With formation of trendline with respect to the size distribution for known and unknown samples, F80 and P80 for respective sub-samples was obtained from the interpolation ...