The specific energy is ultimately determined through actual product testing, but there are a few indicators to predict which mill will be the most efficient. Grinding Media Size Effect The ability to operate a mill with smaller-diameter …

Compared to ball mills, HPGRs are achieving a 30 % to 50 % lower specific energy consumption, although they are not as common as ball mills since they are a newer technology. Suitability of different mills for grinding operations. …

The Total Comminution Specific Energy window at the top of the page gives the specific energy for the entire circuit. It is made up of the sum of any crusher/HPGR net specific energies plus the tumbling mill circuit specific energy at pinion. The associated 95% confidence levels are also shown

4.3.4.2 Calculation for Gate to Gate Specific Energy Consumption (SEC) 6 4.4 Methodology (Summary) 7 5. Target Setting in Cement Plants 7 5.1 Grouping of Cement plants 7 5.2 Energy Consumption Range 8 5.3 Example: Normalised Baseline parameters and Target for PPC 8 5.4 Apportionment of Sub-Sector Target of Energy Saving in Cement Sector 9

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 Classification Rod Mill Ball Mill THIS IS THE REFERENCE BASIS FOR ALL WORK ...

1 Calculation of ball mill capacity. The production capacity of the ball mill is determined by the amount of material required to be ground, and it must have a certain margin when designing and selecting. There are many factors affecting the production capacity of the ball mill, in addition to the nature of the material (grain size, hardness, density, temperature and …

»energy in the case of varying interstitial fillings. Furthermore, changes in mill rotational speed tend to provide energy normalizable breakage rates for· both free dolomite and sphalerite. In all other cases, analysis of the breakage rates and energy specific breakage rates indicate that a change in breakage kinetics may be occurring. '

Wa Specific energy to grind coarser particles in tum-bling mills (kWh/t) Wb Specific energy to grind finer particles in tum-bling mills (kWh/t) Wc Specific energy for conventional crushing (kWh/t) Wh Specific energy for HPGRs (kWh/t) Wi Bond Work Index Ws Specific energy correction for size distribution (kWh/t) WiBM Bond Ball Mill Test Work ...

1 Predicting Mill Feed Specific Energy from Bond Ball Mill Work Index Tests at Olympic Dam Y Li1, V Liebezeit2, K Ehrig3, M Smith4, B Pewkliang5 and E Macmillan6 1. MAusIMM, Senior Geometallurgist, BHP Olympic Dam, Adelaide, South Australia 5000.

The wet ball mill grinding system was operated in open circuit, first grinding coal in No. 6 fuel oil and then grinding coal in water. The air swept ball mill grinding system was returned to service after acceptable specific energy more » values were demonstrated.

Specific Energy Consumption Conversion Factors S. No Description Units Base Line Year (BY) Assessment Year (AY) 1 Total Specific Energy Consumption (Writing ) kcal/Tonne 3534198.26 3261280.66 2 Total Specific Energy Consumption (Paper Board) kcal/Tonne 3028398.973 3002746.136 4 Total Specific Energy Consumption (Speciality)

The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond …

A particle size reduction model has been developed as the first component of an upgraded ball mill model. The model is based on a specific energy-size reduction function, which calculates the particle breakage index, t 10, according to the size-specific energy, and then calculates the full product size distribution using the t 10-t n relationships and the mass-size balance approach.

WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index ... • Calculate the work or specific energy input from the size reduction equipment power and circuit tonnage ... W is the specific energy input (kWh/t), P80 is the 80% passing size of product (µm), and F80 is the ...

where R = radius of ball mill; r = radius of ball. For R = 1000 mm and r = 50 mm, n c = 30.7 rpm. But the mill is operated at a speed of 15 rpm. Therefore, the mill is operated at 100 x 15/30.7 = 48.86 % of critical speed. If 100 mm dia balls are replaced by 50 mm dia balls, and the other conditions are remaining the same,

the ball mill is less energy efficient than a crusher and has to input more energy to do the same amount of size reduction). Hence from equation 7, to crush to the ball mill circuit feed size (x. 2) in open circuit requires specific energy equivalent to: f x f x 2. 1 W c ic. 1.19* 4 2 M x x. 1 (10) For closed circuit crushing the specific ...

In comparison with conventional ball mills, Attritors use fewer resources, including: In addition, Attritors offer the advantage of being able to take samples at any time and making formulation adjustments during high energy ball milling. Alternatively, ball mills are closed systems and do not offer these advantages.

Download Table | e Planetary ball mill data for the calculation of specific energy transfer by the mill. from publication: Grinding of Class-F fly ash using planetary ball mill: A simulation study ...

A new general formula to predict the specific energy of grinding in ball mills and vertimills. Pechea. Published in Proceedings of the IMPC2020 Congress, SAIMM. ABSTRACT. Since 1952, Bond's equation has been used as a standard to predict the specific energy of grinding for a given duty. The Bond's equation considers that the exponent is ...

2 MODELLING THE SPECIFIC GRINDING ENERGY AND BALL-MILL SCALEUP Ball-mill 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)

For ball mill modelling, the small pendulum device was used to test a particle size fraction of 4.75 to 5.6 mm. A fixed specific energy of the order of 1–2 kWh t −1 (depending on the particle density) from a pendulum input energy of 41.788 kg-cm was applied to individual particles in this size fraction.

MODELING THE SPECIFIC GRINDING ENERGY AND BALL-MILL SCALE-UP. September 2004; Conference: Presented at the 11th Symposium on Automation in MMM IFAC, 2004, Nancy - France (IFAC 2004)

The specific energy for this stage is 160 kWh/t. A calculation based on a 1-year period at 93% capacity usage gives a total energy consumption of 7,680 MWh/year. Taking into account an energy cost of $ 70.7MWh, this energy costs can be reduced by $135,744 a year – a very welcome saving for most mills. Based on this situation

Mill Type Overview. Three types of mill design are common. The Overflow Discharge mill is best suited for fine grinding to 75 – 106 microns.; The Diaphram or Grate Discharge mill keeps coarse particles within the mill for additional grinding …

The mill product can either be finished size ready for processing, or an intermediate size ready for final grinding in a rod mill, ball mill or pebble mill. AG/SAG mills can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill, and some or all of the work of a ball mill.

A specific energy-based size reduction model for batch grinding ball mills was reported in a previous paper (Shi and Xie, 2015). A discharge function modified from the Whiten classification efficiency equation has been incorporated in the size reduction model to extend its applications from batch grinding to continuous operation.

where W is the specific grinding energy (kWh/t), W i is the Bond ball mill work index (kWh/t), F80 is the feed 80 pct passing size (μm), and P80 is the product 80 pct passing size (μm). It can be seen that in the regime in which the …