### grindability of the main factorecotoursgambia

In any case with respect to clinker grindability brittleness rather than hardness is the governing factor Inquire Now Grinding Mills Ball Mill Rod Mill Design Parts The mills main drive pinions are fabricated of forged steel and the teeth are carefully cut to

Get Price### Working Principle Of Hardgrove Grindability

Working Principle Of Hardgrove Grindability 222 hardgrove grindability test the hardgrove grindability test procedure was carried out as follows the feed mass was 50 g of μm size interval the loading of the top grinding ring was 290 n the grinding time was 3 min 60 revolutions of the mill at a speed of 20 revmin the test sieve was 75 μm and the hardgrove.

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Ball top size bond formula calculation of the top size grinding media balls or cylpebs Modification of the Ball Charge This calculator analyses the granulometry of the material inside the mill and proposes a modification of the ball charge in order to improve the mill efficiency

Get Price### Physico Chemical Aspects of Grinding a Review of Use

tumbling mills is discussed in terms of com ponent processes taking place inside the mill The past reports on the effect of physico chemical parameters of the environment on mechanical properties and grindability of materials are reviewed Reported mechanisms explaining such effects are analyzed and possible ways to improve the grinding effi

Get Price### AMIT 135 Lesson 7 Ball Mills CircuitsMining Mill

Mill Type Overview Three types of mill design are common The Overflow Discharge mill is best suited for fine grinding to 75106 microns The Diaphram or Grate Discharge mill keeps coarse particles within the mill for additional grinding and typically used for grinds to 150250 microns The Center Periphery Discharge mill has feed reporting from both ends and the product discharges

Get Price### PDF Investigation into the applicability of Bond Work

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

Get Price### The Performance Of Industrial Regrinding Mills Based On

crushing and grinding calculations pdfSlideShare A new approach for evaluating the performance of industrial regrinding tumbling ball mills based on grindability and floatability Mills for the industrial improving the performance of grinding mills in several Comminution 12Minerals Engineering International Online.

Get Price### Bond Efficiency GMG ICE v1 r04 Determining

dard Circuit assume 2.44 m diameter overflow mills and use a rod mill F80 of 16 000 µm and a rod mill P80 of 1 000 µm Note that in order for no correction factor for ball mill product fineness to apply the ball mill circuit P80 should be no less than approximately 70 µm Bond 1962 This

Get Price### A Review of Alternative Procedures to the Bond Ball Mill

standard Bond ball mill in time intervals of 0.5 min 1 min 2 min and 4 min After each grinding run the mass of the sample is measured and the PSD is determined.

Get Price### Grindability Studies of Mineral Materials of Different

These studies have been carried out to compare the grinding characteristics of different morphological mineral matters Coal dolomite manganese and iron ores samples were ground using a ball mill in different grinding conditions dry and wet and at different critical speed R 45 R 70 and R 90 during wet grinding Results are compared considering the relative impact on particle size

Get Price### SPI A Decade LaterSGS

and grindabilityassumptions that have lasted for decades despite mounting evidence suggesting that the relationship is not as strong as we would like By the early 1990 s John Starkey was convinced that a SAG version of the Bond ball mill work index test was needed if the industry was to improve upon current practice John

Get Price### Bond Efficiency GMG ICE v1 r04 Determining

dard Circuit assume 2.44 m diameter overflow mills and use a rod mill F80 of 16 000 µm and a rod mill P80 of 1 000 µm Note that in order for no correction factor for ball mill product fineness to apply the ball mill circuit P80 should be no less than approximately 70 µm Bond 1962 This

Get Price### PROCESS CONTROL FOR CEMENT GRINDING IN

For VRM the production capacity denotes both the capacity of grinding and drying of mill The grindability affects the capacity of grinding type of mill and roller pressure The capacity of the mill is calculated Using GK D 2.51 Where G is capacity of the mill K1 is roller mill

Get Price### Testwork Bond ball mill work indexSAGMILLING

The Bond ball mill work index is one of the most commonly used grindability tests in mining and is often referred to as the Bond work index. The test is a locked cycle test where ground product is removed from test cycles and replaced by fresh feed.

Get Price### Simulation studies on Energy Requirement Work Input

Energy requirement work input and grindability of ball mill have been studied by varying different system parameters viz particle size density of materials number of balls time of grinding and speed of the mill Attempt has also been made to correlate the output with these inputs on the basis of regression analysis Different C programmings were written to compute energy requirement

Get Price### Grinding Circuit Design for Adanac MolySGS

to grindability testing required for the design of a plant for Adanac Moly Corp to include SAG and Ball milling The hardness of each sample was measured 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

Get Price### Effect of Microwave Pretreatment on Grindability of Lead

The influence of microwave pretreatment on grindability of lead zinc ore was studied through comparison analysis on the changes of particle size distribution percentage of below 0.074 mm energy consumption and other indexes of grinding products before and after microwave pretreatment in the ball milling process The results showed that the grindability of lead zinc ore was improved

Get Price### fluorite grindability testweerstationnijverdal

The test is a closedcircuit dry grindability test is run in a standard rod mill and can be performed at sizes ranging from 476 mm to 210 microns The normal finishing size is 12 mm Bond Ball Mill Grindability requires 15 kg of minus 6 mesh material 950 Read More

Get Price### Ball Mill Design/Power Calculation

Ball Mill Power Calculation Example #1 A wet grinding ball mill in closed circuit is to be fed 100 TPH of a material with a work index of 15 and a size distribution of 80 passing ¼ inch 6350 microns The required product size distribution is to be 80 passing 100 mesh 149 microns .

Get Price### Grindability Studies of Mineral Materials of Different

Grindability Studies of Mineral Materials of Different Morphology Materials were ground in a lab scale ball mill for during wet grinding Energy calculations indicated that wet grinding is less efficient for low density and soft materials than high density and

Get Price### IMPROVING THERMAL AND ELECTRIC ENERGY

Improving Thermal and Electric Energy Efficiency at Cement Plants International Best Practice iii LIST OF FIGURES Figure 1 Cement Production Process Flow Schematic and Typical Energy Efficiency Measures . 2 Figure 2 Rotary Cement Kiln Dry Process with Cyclonic Preheaters . 4 Figure 3 Schematic Depiction of Control Points and Parameters in a Kiln System Control and Management

Get Price### Cement GrindingCement Plant Optimization

Ball mill is a cylinder rotating at about 70 80 of critical speed on two trunnions in white metal bearings or slide shoe bearings for large capacity mills Closed circuit ball mill with two compartments for coarse and fine grinding are generally found in cement plants for cement grinding.

Get Price### Relationships between comminution J energy and

The standard Bond ball mill grindability test is a closed circuit dry grinding test with a 250 circulating load The standard procedural outline of the test is stated in Bond 1961 The work index for a ball mill Wi is then calculated from the following equation 7 where P is the closing sieve size m Gbp is the grindability

Get Price### System dynamics model of output of ball mill

AbstractAt present the economic benefits of double inlet and double outlet ball mills which are commonly used in coal fired power plants need to be improved Based on this this paper explores the factors influencing the output of double inlet and double outlet ball mill by establishing the output system of double inlet and double outlet ball mill By analyzing the influence factors of the

Get Price### QUICK METHOD FOR BOND WORK INDEXAPPROXIMATE

unknown ore grindability are compared to reference ore of known grindability This procedure can be carried out in any laboratory ball mill Horst and Bassarear 1976 gave a similar procedure but lasting a bit longer where reference ore data and data of the ore for which the value of the Bond Index is determined are also compared.

Get Price### A study of comminution in a vertical stirred ball mill.

The energy input per ton of grinding media in the stirred ball mill could be 10 times higher than for the tumbling ball mill Although during coarse grinds the media wear was higher in the stirred ball mill than in the tumbling mill it became less so as grinding proceeded and for a product median size of 4.8 microns it

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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.

Get Price### Standard Bond Ball Mill Grindability Test Method Procedure

The Wi value from this equation should conform with the motor output power to an average overflow ball mill of 8 ft interior diameter grinding wet in closed circuit For dry grinding the work input should normally be multiplied by 1.30 However ball coating and packing can increase the work input in dry grinding.

Get Price### Physico Chemical Aspects of Grinding a Review of Use

tumbling mills is discussed in terms of com ponent processes taking place inside the mill The past reports on the effect of physico chemical parameters of the environment on mechanical properties and grindability of materials are reviewed Reported mechanisms explaining such effects are analyzed and possible ways to improve the grinding effi

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The grindability testwork database can accept many common comminution test types including the Bond work index series ball mill rod mill and low energy impact crushing Drop weight tests SAG grindability index SGI minutes to grind to 80 passing 1.7 mm and

Get Price### Cement Grinding OptimizationSlideShare

Wm = Wi 80P 1080F 10 1 where Wmis mill specific motor output power kWh/t Wiis the Bond ball mill work index kWh/t P80is sieve size passing 80 of the mill product µm F80is sieve size passing 80 of the mill feed µm The efficiency factors Rowland 1975 modify equation 1 so that it caters for circuit

Get Price### PROCESS DIAGNOSTIC STUDIES FOR CEMENT MILL

The mill performance is evaluated and recommendations are formulated based on the past history of the mill operations inspections process measurements feed/product characteristics and grinding performance in order to improve mill output and reduction in power consumptions in the ball mill system DIAGNOSTIC STUDY History of mill operations

Get Price### Bond Work Index TestsGrinding Solutions Ltd

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 100 passing size of <3.35 mm.

Get Price### Analysis of the Effects of Blasting on Comminution Using

The work index was determined using standard rod mill tests and relative ball mill grindability tests Berry and Bruce 1966 It was found that the rod mill work index of granodiorite decreased by 3 and 8 in the fragments 11.2 mm and − 11.2 mm respectively that were produced by blasting with a powder factor of 0.95 kg/m 3 compared to

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conventional crushing and grinding circuits crusher rod ball mill or crusher ball mill By the 1970s the application of conventional tended to be limited to relatively low capacities circuits The majority of modern grinding circuits include a SAG mill a ball mill and/or a

Get Price### The SAG grindability index testScienceDirect

The mill reportedly rotates at 70 of critical velocity Verret et al 2011 or 54 rpm Gonzalez 2000 .There is controversy surrounding the mill rotational speed The calculation of mill critical velocity V c is derived from the balance of gravitational force and the centrifugal force acting on a ball and is given by Eq after Austin and Concha 1994 1 V c = 42.2 D d where D is the

Get Price### Effect of Thermal Shock on Grindability of Oleic Adsorbed

Thermal shock is one of the most effective techniques in size reduction The present investigation deals with the effect of thermal shock treatment on grindability and grinding characteristics of sillimanite minerals and also an attempt has been made on the overall energy saving for preparation of sillimanite flour by using ball mill This attempt is made due to a fine dry grinding of

Get Price### Calculation of energy required for grinding in a ball mill

The grinding product size P in a Bond ball mill which is given by the aperture size which passes 80 of the grinding product as a function of the aperture size of the test screen Pk can be expressed by the formula P= P k K 2.

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