Template:BarrattEtotalEquation

Barratt Total Circuit Specific Energy Equation

This is a basic equation of the family of Bond/Barratt calculations. It describes specific energy requirement of a grinding circuit consisting of primary SAG (or Autogenous) mills and secondary ball mills.

Testwork Required

• Bond ball mill work index
• Bond rod mill work index
• Bond crushing (low-energy impact) work index

Discussion, Underlying Theory

The formula assumes that:

• The breakage properties of an ore is a function of measured hardness value; in this method the three Bond work index values.
• There exists a "maximum efficiency" grinding circuit configuration: the multi-stage crushing and single-stage ball mill circuit.
• The grinding specific energy requirements of different grinding circuit configurations can be related by comparing their efficiency relative to the "maximum efficiency" circuit.

The maximum efficiency circuit is described by the Rowland E_ssbm equation

Formula

$E_{total} = </noinclude> E_{ssbm} \times (1+CF) <noinclude>$

where:

• E_ssbm is the Rowland specific power consumption for a multi-stage crushing and single-stage ball mill circuit.
• CF is a contingency factor that relates the grinding efficiency of the circuit being modelled versus the "maximum efficiency" circuit.

Model defaults

In general, the CF value for a well-designed SABC circuit is 0.10 and the CF value for a well-designed SAB circuit is 0.15.

Links

See list of pages that use this formula: