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

Obtener precioAdditionally while techniques like the Bond Work Index and scale up factors are useful for coarse grinding, they can significantly underestimate grinding needs below 100 microns. Similarly Tower Mill laboratory tests typically use much finer media than can be used in full scale operation and testwork is done in batch mode.

Obtener precioBall 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 . Cement grinding Vertical roller mills versus ball

Obtener precioRock Characteristics and Ball Mill Energy Requirements at Goldfields Ghana Limited, Tarkwa Gold Mine (TGM)* C. E. Abbey, K. J. Bansah, G. Galecki, and K. A. Boateng parameters examined had deviated from the design; Work Index (WI) for example was lower than design and required in a standard Bond ball mill with weight of material

Obtener precioBond work index analysis is based on energy usage. Because energy costs and the ball mill circuit "classification system efficiency" (CSEff). It is the percentage of "coarse" material in the ball mill, factors, such as grinding ball sizing and percent solids in the mill

Obtener precioCorrelations for the Grindability of the Ball Mill As a Measure of Its Performance By standard equation used by them for the ball mill work index (Bond work index) is as follows. a 25 − 2 design is 1/4 of a two level, five factor factorial design. Rather than the 32 runs that would be required for the full 25 factorial experiment,

Obtener precioA ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints.Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles and stainless steel balls.

Obtener preciopressure grinding rolls (HPGR) products based on a Bond mill test procedure. Multiple trade-off studies have reported the performance of HPGR versus SAG milling with energy savings of between 11 and 32 per cent. One factor that is often inconsistently defined in these studies is the change in the Bond Ball Work Index (BBWi).

Obtener preciobond method for ball mill work index test This Grindability Test or Bond Ball Mill Work Index Procedure is used to determine the Bond Work Index of minus six mesh or finer feed ore samples. These equation application methods are used to process 1/2 ore samples in a Ball Mill using a standard ball

Obtener precioJul 31, 2014Mill power draw prediction can be carried out using Morrell's power model for tumbling mills (Morrell, 1998). Bond method The established technique for determining power requirements for ball mills is the Bond method (Bond, 1961). This method also involves the application of some 'efficiency factors' as described by Rowland (1975).

Obtener precioEnergy requirements for crushing and HPGR options can now be determined in addition to AG/SAG mills, and with Mic, ball mills. The results from conducting the SMC Test are used to determine the so-called drop-weight index (DWi) which is a measure of the strength of the rock.

Obtener precioDefinition, objectives of size reduction and size separation, factors affecting size reduction, laws governing energy and power requirements of mills including ball mill, hammer mill, fluid energy mill etc., sieve analysis, standards of sieves, size separation equipment shaking and vibrating screens, gyratory screens, cyclone separator, air separator, bag filters, cottrell precipitator

Obtener precioYes, we can assist with optimisation. To achieve this at both the design and operating stages, we will require some representative sample for specific comminution test work. The test work will entail industry standard tests such as the Bond Rod Mill Work Index, Bond Ball Mill Work Index, JK/DWi tests and then some specific batch mill tests.

Obtener precioOf these laws, Bond's third law of comminution Cl,21 has developed the largest following as a result of the Bond Work Index Wi. This index can easily be deter-

Obtener precioChanging the effective liner thickness of the SAG mill to 4.5 inch and the ball mills to 3.0 inches results in 1490 t/h throughput prediction (7.1% difference versus the measured throughput). The assumed crushing work index (20) suggests a very competent ore compared to most in British Columbia — this matches comments at the SAG conference.

Obtener precioPublished in Asia-Pacific Journal of Chemical Engineering 2008Authors Abanti Sahoo G K RoyAffiliation National Institute of Technology RourkelaAbout Ball mill Particle size Fractional factorial design### Grinding Circuit Design for Adanac Moly sgs

in terms of SAG power index, SPI (for SAG grinding) and Bond Ball mill work index, BWi (for ball mill grinding). A further measure, the Minnovex crusher index, Ci was also measured for use in the CEET program to determine SAG mill feed size (Kosick and Bennett, 2001). The SPI values varied from 13.5 to 107 minutes with an average of 53 minutes.

Obtener precioBond ball mill work index Figure 2 Ball mill for determining Bond ball mill work index 1 For the purists, there were two models in existence at the time the Von Rittinger and Kick models. Neither of these gave results that matched the observations of specific energy consumption from tumbling mills.

Obtener precioRAPID RAMP-UP OF THE TROPICANA HPGR CIRCUIT *Fred Kock1, Leigh Siddall1and Ivka-Anna Lovatt1, Mark Giddy2, Factors that influenced the selection of the circuit type are examined and 1 The power necessary for the flowsheet is compared to the Bond Ball Mill Work Index based power that is

Obtener precioThe bond grindability index and work index of ball mill were determined for different feed characteristics by varying the number of balls involved in grinding operation in the ball mill. The higher specific rate of breakage was obtained for new or smooth surfaced balls than old or rough surfaced balls.

Obtener precioApr 01, 2001In-circuit crushing and external conveyors were not wanted. Energy and grinding efficiency for both the SAG and ball mills were foremost in design considerations. A large number of ore samples were tested for hardness using the Bond work index and the MacPherson autogenous work index.

Obtener preciobond f.c. crushing and grinding calculations Crushing and Grinding Calculations Scribd Fig. 1. 84-in. Hydrocone crusher lor tertiary crushing 01 Semi-Taconite are Read more crushing grinding calculation free Coal Crusher

Obtener precioA general prediction model for the Hardgrove grindability index was constructed from 735 coal samples using the proximate analysis, heating value, and sulfur content. The coals used to develop the general model ranged in volatile matter from 12.8 to 49.2 percent, dry basis, and had grindability

Obtener precioMill(orcircuit)performance,particularlyontheWrtwatersrand,isoftenindicatedbytheindex kilowatt~urs pertonneofminus 75 J.II11material produced(kWM minus75 J6fI orO~75)'Thepaper shows that a standard kWM minus 75J.II11index(SE~)canbeobtained from the standard Bond grindability test (which prOllides

Obtener precio12.10 Determining the Bond ball mill work index with fewer cycles D. Garcia (University of Queensland, Australia), G. Ballantyne (JKMRC, Australia) and H. Liang (JKTech Pty Ltd, Australia) 12.30 Development of a laboratory test for regrinding ball mill or stirred mill circuits

Obtener precioThe 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. The Rod Mill Work Index (RWI) is used for particle size determination in a size range from 25 mm down to 2.1 mm whereas Ball Mill Work

Obtener precioThe product size distribution is narrower than a ball mill but significantly coarser. Most are overflow discharge type. Length-to-diameter= 1.4 to 2.3. Mill length = 7 meters. Rod Mill-Ball Mill Circuits Diagrams of mill circuits

Obtener precioLecture Mechanical Process Engineering Tutorial Comminution Task 1 Calculation of the Bond working index A wet-discharge chamber ball mill (grinding chamber diameter is 𝐷 = 3100 mm, length 𝐿 = 3200 mm), which works in a circuit with a hydrocylone, mills siliceous material with Calculate the work index of Bond 𝑊

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Obtener precioThe 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

Obtener precio8 January 2013 Conroy Gold and Natural Resources plc crushing and other factors in relation to mill design. The test work undertaken included Bond Rod Work Index (BRWi), Bond Ball Work Index (BBWi), Bond Abrasion Work Index (Ai) and SAG Mill Comminution Test (SMC). The latter was carried out on behalf of Goldfields by JKTech

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