### FM 306: SIZE REDUCTION AND SIEVING

FM 306: SIZE REDUCTION AND SIEVING OBJECTIVE •To grind the given limestone material to a smaller size using a ball mill and to obtain the size distribution of the initial and the final mixture by sieving. Bonds law is often written in terms of the work index (Wi) as,

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Ball Mill Work Index Calculation. For any circuit whether a crushing circuit a rod mill or a closed ball mill circuit the Work Index always means the equivalent amount of energy Get Price Procedure for determination of ball Bond work index in . Details Appliion Of Operating Work Indices In

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Ball Mills are generally used to grind material 1/4 inch and finer, down to the particle size of 20 to 75 microns. To achieve a reasonable efficiency with ball mills, they must be operated in a closed system, with oversize material continuously being recirculated back into the mill to be reduced.

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Where operating work index (kwh/t) isWiop, mill power draw (kw) isW, Q is mill throughput (t/h) andP80,F80 are respectively mill product and feed size distributions. Operating Bond index is not comparable to laboratory standard Bond index therefore a few correction factors should be multiplied to obtain of corrected operating Bond index[13, 17].

Get price### MODELING THE SPECIFIC GRINDING ENERGY AND BALL

2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALLMILL SCALEUP Ballmill scale up (Bond''s 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)

Get price### MODULE #5: FUNCTIONAL PERFOMANCE OF BALL MILLING

In the prerequisite module entitled "Work Index Efficiency" you have learned about work index analysis* to define overall grinding circuit efficiency. In rod milling, you can use work index analysis to relate design and operating variables to overall circuit efficiency. However, you cannot use work index analysis for the same purpose on ball mill

Get price### Bond Grinding Circuit Efficiency

Mill Ball Mill Closed circuit crushing to 16 mm Open circuit 8'' dia. rod mill to 1 mm Closed circuit 8'' dia. ball mill to P80 um The ore Test Work Index = Circuit Operating Work Index 9 The Standard Bond Circuit Coarse Ore Bins Fine Ore Bins Screen Crushing Screen Classifiion Rod Mill Ball Mill THIS IS THE REFERENCE BASIS FOR ALL WORK

Get price### Grinding in Ball Mills: Modeling and Process Control

Grinding in Ball Mills: Modeling and Process Control Vladimir Monov, Blagoy Sokolov, Stefan Stoenchev the work index of the material, the mill shaft power and depending on the type of the mill, the operating conditions and the type of the material being ground.

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ball mill work index calculation xls. Ball top size diameter calculation Pf = size in µ of the 80% passing in the fresh feed C = 200 for ball mills and 300 for rod mills Wi = Work index Vcr = percentage of the critical speed Sgs = specific gravity of feed in t/m3 D = internal diameter of mill in m .

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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.

Get price### Operational work index for grinding plants ScienceDirect

Work indices obtained from operating data on any mill can be compared to grindability test results. The operating work index, Wiop, can be obtained using Bond''s equation by defining W as the specific energy being used (power draw/new feedrate), f80 and p80 as the actual feed and product 80% passing sizes, and Wi as the operating work index, Wiop.

Get price### How to Measure Grinding Efficiency

The first two Grinding Efficiency Measurement examples are given to show how to calculate Wio and Wioc for single stage ball mills. Figure 1. The first example is a comparison of two parallel mills from a daily operating report. Mill size 5.03m x 6.1m (16.5′ x 20′ with a ID of 16′).

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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.

Get price### USING THE SMC TEST® TO PREDICT COMMINUTION

work index covering grinding of fine particles is labelled M ib (Morrell, 2008). M ia values are provided as a standard output from a SMC Test® (Morrell, 2004a) whilst M ib values 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

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Operating Ball Mill Efficiency Eagleeyes.cz. Operating ball mill efficiency, Effect of ball and feed particle size distribution on the milling Effect of ball and feed particle size distribution on the milling efficiency of a ball mill: The size reduction unit operation is known to be the m. Online Chat

Get price### GMSG GUIDELINE: DETERMINING THE BOND EFFICIENCY OF

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 to approximately 70 m, and perhaps no finerµ, without making qualifiions. Calculations: First, calculate the actual Operating Work Index, WloACT, of the

Get price### Comminution an overview ScienceDirect Topics

Example 5.2. a. A survey of a SAGball mill circuit processing ore from primary crushing showed size reduction of circuit (SAG) feed F 80 of approximately 165,000 µm to flotation circuit feed (cyclone overflow) P 80 of 125 µm. The total specific energy input for the two milling stages was 14.6 kWh t −1.Calculate the operating work index for the circuit.

Get price### USING THE SMC TEST® TO PREDICT COMMINUTION

work index covering grinding of fine particles is labelled M ib (Morrell, 2008). M ia values are provided as a standard output from a SMC Test® (Morrell, 2004a) whilst M ib values 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

Get price### Energy efficiency in mining 3/4: Refits

By adding a VTM3000 their overall specific energy consumption increased, which normally would mean that the circuit was more inefficient. However, in this case their operating work index actually dropped. This was a successful appliion of the Vertimill technology from both an energy efficiency and value recovery points of view.

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approach acknowledges grinding efficiency as the ratio of operating work index to that for a singlestage ball mill. The Barratt approach is the basis of the Millpower 2000 computerbased program (Matthews and submitted to the Bond ball mill work index test. The number of SAG mill revolutions required to grind the material to a P

Get price### Appliion of Operating Work Indices in Autogenous

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 profitability. Mill operators have long used operating

Get price### Evaluation Index of Ball Mill Grinding Work Xinhai

In practical work, operating rate, productivity, specific productivity, grinding efficiency, and technology index are often taken as the standard to evaluate the quality of the grinding work. 1. Operating Rate. Ball mill operating rate is the ratio, which the actual time of operating is to the total hours'' calendar during the work.

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Ball Mills are generally used to grind material 1/4 inch and finer, down to the particle size of 20 to 75 microns. To achieve a reasonable efficiency with ball mills, they must be operated in a closed system, with oversize material continuously being recirculated back into the mill to be reduced.

Get price### Bond Work Index Tests Grinding Solutions Ltd

Bond Work Index Tests. Grinding Solutions offers a range of Bond Work Index Testing from crushability and abrasion to ball and rod mills. For more information on the tests please see below: Bond Low Energy Impact Test. The Bond LowEnergy Impact test can be used to determine the Crusher Work index (CWi), also known as the Impact Work Index.

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calculations define the efficiency of a fine stagecrush ball mill circuit as 1.0 to 1.2 depending on ball mill feed size, and some SABC (SAG/ball mill/pebble crusher) circuits operating with an efficiency of 1.31.4 or higher on coarse feed. If the coarse feed size is reduced, the circuit efficiency will approach that of the stagecrush and

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Bond Rod Mill Grindability Test. The test determines the Bond Rod Mill Work Index which is used with Bond''s Third Theory of Comminution to calculate net power requirements when sizing ball mills*. Various correction factors may have to be applied. The test is a closedcircuit dry grindability test performed in a standard rod mill.

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The operating principle of the ball mill consists of following steps. In a continuously operating ball mill, feed material fed through the central hole one of the caps into the drum and moves therealong, being exposed by grinding media. The material grinding occurs during impact falling grinding balls and abrasion the particles between the balls.

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The KnowledgeScape solutions work together to see, listen, and think about the best way to increase tonnage at all times and for all conditions. Our ball mill strategies automatically adjust sump water and mill water addition, mill speed where available and can open and close cyclones when appropriate.

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A 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.

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Sep 19, 2016 · Ball mill grinding Ramkrishna 1. Improvement of Ball MillImprovement of Ball Mill grinding efficiencygrinding efficiency Presented ByPresented By Ramkrishna HalderRamkrishna Halder Under the guidance ofUnder the guidance of Dr. Preeti BajpaiDr. Preeti Bajpai 11 2.

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Ball Mill. Ball mill is the key equipment for grinding after the crushing process, which is widely used in the manufacture industries, such as cement, silie, new building material, refractory material, fertilizer, ferrous metal, nonferrous metal and glass ceramics and can be used for the dry and wet grinding for all kinds of ores and other

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The resultant operating work index of the ball mill will vary according to the ratio of the ball mill, rod mill and crushing work index values and for an Andean copper porphyry is typically in the range of 80% of the measured ball mill work index value. Testwork Required. Bond ball mill work index Bond rod mill work index

Get price### MODELING THE SPECIFIC GRINDING ENERGY AND BALL

2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALLMILL SCALEUP Ballmill scale up (Bond''s 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)

Get price### Energy Saving Ball mill,Ball grinder,Ball grinding mill

Appliion: Energy saving mining ball mill is a key equipment in beneficiation plant.It is widely used in ore dressing production line such as Gold ore, Cooper ore, Magnetite ore, Antimony, Calcite, Kaolin, Mica, Clay, Bentonite etc Ferrou metal or Nonferrous metal materials.

Get price### (PDF) A quick method for bond work index approximate value

A quick method for the Bond work index approximate value determination, which is based on the first order grinding kinetics, is presented in this paper. the Bond mill operating under the sam e

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Procedure for determination of ball Bond work index in the commercial operations Bond Ball Mill Work Index which expresses the resistance of material to ball milling. be used as a guide to

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