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A mill power equation for SAG mills

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Abstract

Development of an equation for tumbling charge and balls plus comparison to plant data suggests that the net mill power for cylindrical semiautogenous mills can be calculated from

$${m_p} = 10.6{D^{2.5}}L\left( {1 - 1.03J} \right)\left[ {\left( {1 - {\varepsilon _B}} \right)\left( {{\rho _s}/{w_o}} \right)J + 0.6{J_B}\left( {{\rho _b} - {\rho _s}/{w_c}} \right)} \right]\left( {{\phi _c}} \right)\left( {1 - \frac{{0.1}}{{{2^{9 - 10\phi }}c}}} \right)$$

where mp is in kW; D is internal mill diameter (meters), L is internal mill length (meters); J is total fractional charge loading of the mill; JB is the fractional mill filling by balls; εB is the effective porosity of the charge, taken as 0.3; ρsand ρb are true densities of rock and balls (tons per cubic meter), respectively; wc is the weight fraction of rock in water and rock in the mill, taken as 0.8; and ϕc is the fraction of critical speed. Equations are given for corrections for the conical end sections.

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Authors and Affiliations

  1. Mineral Engineering Dept., The Pennsylvania State University, University Park, PA, USA

    L. G. Austin (member SME, professor)

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  1. L. G. Austin
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Additional information

M&MP paper 88-627. Manuscript Apr. 7, 1988. Discussion of this paper must be submitted, in duplicate, prior to May 30, 1990.

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Austin, L.G. A mill power equation for SAG mills. Mining, Metallurgy & Exploration 7, 57–63 (1990). https://doi.org/10.1007/BF03403284

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