Model:Amelunxen SGI

Amelunxen SGI Model

This is a SAG or AG mill plus ball mill model that estimates the specific energy consumption (E_SAG) using the equation by Amelunxen (2014) and the classical Bond work index equation substituting CF_ball in the place of the Rowland efficiency factors. The model requires manual calibration factors for both equations (CF_SAG and CF_ball, respectively).

Testwork Required

• SAG grindability index
• Bond ball mill work index

Formulae

$E_{SAG} = 5.9 \times SGI^{0.55} \times T_{80}^{-0.275} \times CFsag$^{Amelunxen, 2014}

$E_{ball} = W_i \times \left ( \tfrac {10}{\sqrt{ P_{80} }} - \tfrac {10}{\sqrt{ T_{80} }} \right ) \times CF_{ball}$

CF_sag calibration factor

The CF_sag factor is used to reflect the effect of pebble crushing and pre-crushing on the overall circuit performance.

• Base value, SAB circuit (no pebble crushing, ~6 inch SAG feed), CF_sag = 1.00
• Pebble crushing, SABC circuit, CF_sag = 0.85
• Pre-crushing, (fine SAG feed, -2½ inch SAG feed), CF_sag = 0.90
• Pre-crushing and pebble crushing, CF_sag = 0.85 × 0.90 = 0.77

CF_ball calibration factor

The CF_ball is a manually picked value used to lump the phantom cyclone effect and the variety of Rowland efficiency factors into a single factor. This value is usually picked based on a mill survey, or taken from a diagram such as Figure 5 from Becerra & Amelunxen (2012)^Bibliography.