Determination Of The Bond Work Index Using An Ordinary . 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 …
This Table of Ball Mill Bond Work Index of Minerals is a summary as tested on 'around the world sample' You can find the SG of each mineral samples on the other table. Live Chat. Ball Mill Operation Clinker. working of ball mill with gypsum and clinker - Mine, used clinker ball mill crusher, a success story consumption in existing ...
ball mill indexing unit - lipno-manava31cz - Know More. 04-05-2021· Bond Work Index an overview ScienceDirect Topics The ball mill work index laboratory test is conducted by grinding an ore sample prepared to passing 336 mm (6 mesh) to product size in the range of 45-150 µm (325-100 mesh), thus determining the ball mill work index (Wi B or BWi)...
First, a Jar Mill grindability test requires a 5 lb. (2 kg) sample and produces a direct measured specific energy (net Hp-hr/t) to grind from the design feed size to the required product size. The second test, a Bond Work Index determination, results in a specific energy value (net Hp-hr/t) from an empirical formula.
An alternative mill ball charge is proposed that closely approximates Bond's original total ball mass, number of balls and ball surface area. Results of 30 Bond Work index tests of six pure materials (calcite, magnesite, labradorite (feldspar), quartz, andalusite and glass) using closing screen apertures (P 1) values of 500, 250, 125, 90 and 63 ...
For overflow ball mills, the charge should not exceed 45% of the mill volume . For grate discharge mills, the charge should occupy about 50% of the mill volume . Bond developed a relationship that can be used to determine the percent charge by volume as a function of the vertical height above the charge, He, and the radius of the mill, R, i.e.,
The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index. For grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill (see Figure 3.10), a question arises as to whether this practice will alter the ball mill work index (BW i) of the …
The work index obtained following the standard Bond grindability test described above predicts the energy requirement for a 2.44 meter (8ft.) inside liners diameter, prototype ball mill under the following conditions: 1. Wet closed circuit grinding. 2.
Bond/Rowland SSBM Circuit model: Set the crusher product size to 6000 µm; Circuit feed size 160 000 µm and product size 100 µm; Adjust the Essbm calibration factor to get E ball of 11.8 set Essbm calibration factor to (-0.13) Gives a throughput of 4400 t/h. gives 5% reduction in ball mill operating work index (13.6) versus laboratory Wi (14.4).
Bond ball mill work index determination the bond grindability test the bond work index and uncil for tion of the energy consumed by wet grinding in a ball mill of 8 ft 244 materials that are too fine for determination by the stan dard bond chat online bond ball mill work index database jktech. Online Chat Andesite Bond Price List Ball Mill Work ...
Bond Work Indexan overview ScienceDirect Topics. The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index For grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill see Figure 3.10 a question arises as to whether this practice will …
However, Bond Work Indeces are related to the type of equipment to be used (rod mill, ball mill, SAG uses Drop Ball parameter-Kwhr/m3-, so it is more complex than just specific energy consumption ...
where CF is the Essbm calibration factor (in the Circuit Settings) for ball mill operating work index versus laboratory ball mill work index. A value of zero means use the Bond/Rowland SSBM formula to predict E ball, a value of -0.05 means use 5% less than Bond/Rowland SSBM formula to predict E ball. CF is a negative number if Wi O is less than ...
Work Index KWh/t Unki ore 75 1906.18 57.56 18.2 150 1906.18 114.02 15.0 The above confirms that the design BWI for the primary ball mill is between 15 kWh/t and 18.2 kWh/t. As will be shown later, for sizing the primary mill motor the Bond method is used. The
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 the test is run at the wrong product size, then it is necessarily to provide a correction. The goal of this work is to create an equation to adjust a Bond ball mill work index from one P 80 basis
Ball Mill Wio, BWio 8.6 Circuit Wio, OWio 14.6 Bond Ball Mill Work Index, BWi, kWh/t 13.4 Bond Rod Mill Work Index, RWi, kWh/t 18.1 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 Work Index (BWI or Wi) is defined as the calculated specific energy (kW h/t) applied in reducing material of infinite particle size to 80% passing 100 μm [25]. The higher the value for Wi, the more energy is required to grind a material in a ball mill [10], [26].
Bond Work Index (BWI) & Hardgrove Grindability Index (HGI) tests for biomass & 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 pre-densified particles close to the target size. •
• The Bond Ball Mill Grindability Test determines the Bond Ball Mill Work Index used to determine net power requirements when sizing ball mills. The test is a closed-circuit, dry grindability test. It is run in a standard ball mill and can be performed at mesh sizes ranging from 48 mesh to 400 mesh. Bond Ball Mill Work Index (and modified ...
can be determined using the data generated by a conventional Bond ball mill work index test (M. ib. is NOT the Bond ball work index). M. ic. and M. ih. values are also provided as a standard output from a SMC Test ® (Morrell, 2009). The general size reduction equation is as follows (Morrell, 2004. b): f x f x 2. 1 i i. 4 2 W M x x. 1 (1) where ...
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.
FIGURE 8: ROD MILL/BALL MILL WORK INDEX RATIO v. UNCONFINED COMPRESSIVE STRENGTH 100 200 300 400 UCS (MPa) 0 0.5 1 1.5 2 WiRM/WiBM (metric) Siddall et al (1996) identified the ratio of Bond rod mill Work Index and ball mill Work Index as being indicative of an ore's compentency. Figure 8 plots this ratio versus UCS; no trend is apparent ...
The Bond Index conforming rod charge consists of: 6 rods of 1.25" diameter and 21" length. 2 rods of 1.75" diameter and 21" length. The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a wave-shaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill.
Ball Mill Design/Power Calculation. 19/06/2015 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 tonnage capacity DTPH, operating % solids or pulp density, feed size as F80 and maximum 'chunk size', …
The Work Index (BWi) is calculated according to Fred Bond's Equation. Bond Work Index for Testing Procedure. Cleaning and Storing of Ball Mill Charge after the Bond Work Index Procedure is done: Add about 500 g of silica sand into the mill containing the ball charge. Seal the mill. Rotate for 20 revolutions to clean.
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 …
rod mill work index has not been de ned as yet. The ball fi mill work index is con rmed at 16 kWh/t. The operating fi work index, though, is in the range of 21 kWh/t to 25 kWh/t showing high ineffi ciency. This raises the point that, in some cases, the Bond EF4 oversize factor calculation is not suf cient to compensate fi
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.
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