Comminution theory is concerned with the relationship between energy input and the particle size ... 80 of 1.7 mm is used to predict AG/SAG specific energy using Equation 3 and other power-based models available in CEET (Comminution Economic Evaluation Tool). ... BM = Ball mill specific energy from T 80 1.7 mm to final product P 80, using Bond ...

The relationship between the power group (P/D6N²e) and the group (Nc/N), as determined by experiment, is shown in Fig. 3.2, and it is seen that for speeds less than 80% of the critical, the relationship Ø1′ (Nc/N) can be replaced by Ø1′ (Nc/N') = K2 (Nc/N)² ………… (3.9) where K2 = 3.13 for lifter mills and 3.66 for mills without lifters.

The empirical equation by Hogg and Fuerstenau, although formulated on a simple concept of charge being lifted from the toe to the shoulder of the mill, predicts power very close to operating plant data. It is shown that this equation ball mill power draws very reasonably. However, SAG mill power prediction requires additional development.

to a given energy input is summarised in the elegant relationship given in equation 1, providing the A ... values across a SAG-ball mill circuit to assess the performance of ... versus energy ...

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, …

Abstract 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 fro...

C Energy per unit thickness to break a particle (J/mm) ... size reduction equipment power and circuit tonnage (equation 1). Auxiliary equipment power is excluded. P W = ––– (1) T Where, W is the specific work input (kWh/t), P is the equip- ... Ball Mill, or …

One area that is usually ignored is the relationship between media shape and mill power. The objective of this dissertation was to investigate how media shape affects grinding. Ball size distribution inside an industrial mill was analysed in terms of shapes and sizes. Load behaviour, mill power and breakage as affected by media

A theoretical energy–size reduction relationship is derived for tumbling ball mills based on a solution of the integro-differential equation of comminution kinetics, in which the proportional relationship is applied between the grinding rate constant and the net mill power. The derived formula is similar to an empirical energy law, dW ∝ dx ...

The motor power draw required to turn a mill from rest to the operating speed includes the energy required for the initial starting torque and mechanical arrangements to rotate the mill. It is generally accepted that practical mill power (PM ) is a function of mill capacity and diameter, i.e.,P M = Mill Constant * (Mill Diameter ) n

Ball mill power draw predicted from the Denver slide rule, kW 0 200 400 600 Calculated ball-mill power draw from the m odel derived, kW Data compared Line y=x Fig. 2. Comparison of the ball mill power draw from the Denver slide rule and the …

Rowland, Chester A, Bond's Method for Selection of Ball Mills, Advances in Comminution, ed. S. K. Kawatra, SME 2006, Pages 385 - 397 EF factor formulae are taken from Rowland, Chester A, Selection of Rod Mills, Ball Mills and Regrind Mills, Mineral Processing Plant Design, Practice & Control, SME 2002, Pages 710-754.

mill is the energy consumption. The power supplied to the mill is used primarily to lift the load (medium and charge). Additional power is required to keep the mill rotating. 8.1.3 Power drawn by ball, semi-autogenous and autogenous mills A simplified picture of the mill load is shown in Figure 8.3 Ad this can be used to establish the essential ...

W = power consumption expressed in kWh/short to (HPhr/short ton = 1.34 kWh/short ton) Wi = work index, which is a factor relative to the …

The most common form of this relationship is given as Equation 1, and is often referred to as "Bond's equation" or "Bond's law." ... Both of these examples give numeric values that are specific energy consumption: the power draw of the mill ... means that all ball mill work index tests should be run to achieve a P80 of 100 µm ...

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., Charge% = 113- (63H C /R) However, Morrell identified significant errors from this estimate when using small media sizes. Charged ball mill [image: (135-7-9)]

Since for the ball mill design we are using 80% passing, the required value of C2 for the ball mill will be equal to1.20. C3 is the correction factor for mill diameter and is given as; 𝐶𝐶3 = 2.44 𝐷𝐷 0.2 (3) However, it is important to note that C3 =0.914 vessel used in …

If P is less than 80% passing 70 microns, power consumption will be. Ball Mill Power Calculation Example. A wet grinding ball mill in closed circuit is to be fed 100 TPH of a material with a work ...

What is the energy requirement per tonne of ore and the total ball mill power requirement? (20 marks) c) to produce a saleable zinc concentrate, the Century concentrator in Australia must regrind its concentrate from 80% passing 37 microns to 80% passing 15 microns in Isamills, The feed concentrate tonnage is 500,000 mtra (metric tons per year).

generate mill energy data to support a measured size-energy relationship f or ball mills that would be comparable with the theoretic al equations …

While the data were evaluated within the scope of energy-size reduction relationship for vertical roller mills, Morrell's equation (Morrell, 2004) was based on. The K parameter for present data was back calculated and a preliminary energy-size relationship was developed to predict the grinding energy of the vertical roller mill.

Ball mills are predominantly used machines for grinding in the cement industry. Although ball mills ... the ball mills for obtaining maximum production and minimum specific energy consumption. ... Roller press in semi finish and finish grinding mode .... The velocity of gases calculated through mill is 1.29 m/sec.

Abstract Despite reservations of a number of researchers concerning the applicability of Bond's equation for relating specific energy to the size reduction of rocks, his approach has become an industry standard. Data from a large number of pilot and full-scale autogenous (AG), semi-autogenous (SAG) and ball mill circuits are used to show that Bond's equation does not hold …

Mill power Usually, plant operators use mill power readings as an indicator of ball filling degree and, often, try to keep it at the maximum level. It is well known that the mill absorbed power depends on operating parameters other than ball level, such as pulp density and liner configuration. Figure 2 shows that there is no linear relation between

mills with the rod mill and ball mill laboratory work indices. Note, in Figure. 1, that the rod mill product slope is less than 0.5 due to an extra amount of nes present being ﬁ ﬁ ner than 650 μm. These ﬁ nes proceed to the ball mill improving the ball mill efﬁ ciency. Also, the plotted rod mill P80 value, as shown in Figure 1, is 2900 ...

The image above represents the specific power of mill. To compute for specific power of mill, three essential parameters are needed and these parameters are Work Index of Ground Material (w i), 80% Product Size (P 80) and 80% Feed Size (F 80). The formula for calculating the specific power of mill: E = w i (10 / √(P80) – 10 / √(F80)) Where:

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 …