Comminution Circuit Specific Energy (Bond)

Description

This article describes the Bond method for estimating the specific energy of comminution circuits.

Model theory

This section is currently under construction. Please check back later for updates and revisions.

Excel

The Bond specific energy model may be invoked from the Excel formula bar with the following function call:

=mdMillPower_BondWI(Parameters as Range)

Invoking the function with no arguments will print Help text associated with the model, including a link to this page.

The Parameters array and model results are defined below in matrix notation, along with an example image showing the selection of the same arrays in the Excel interface:

[math]\displaystyle{ Parameters= \begin{bmatrix} \mathit{WI}\text{ (kWh/t)}\\ F_{80}\text{ (}\rm{\mu}\text{m)}\\ P_{80}\text{ (}\rm{\mu}\text{m)}\\ \text{Dry grinding (True/False)}\\ \text{Open circuit (True/False)}\\ \text{Control fraction passing (frac)}\\ D\text{ (m)}\\ L\text{ (m)}\\ \text{Rod mill (True/False)}\\ \text{Rod mill only circuit (True/False)}\\ \text{Closed circuit crushing (True/False)}\\ \end{bmatrix},\;\;\;\;\;\; \mathit{mdMillPower\_BondWI} = \begin{bmatrix} W\text{ (kWh/t)}\\ \mathit{EF1}\\ \mathit{EF2}\\ \mathit{EF3}\\ \mathit{EF4}\\ \mathit{EF5}\\ \mathit{EF6}\\ \mathit{EF7}\\ \mathit{EF8}\\ \end{bmatrix}\;\;\;\;\;\;\;\;\;\;\;\; }[/math] where: [math]\displaystyle{ \mathit{WI}\text{ (kWh/t)} }[/math] is the Bond Work Index of the ore being processed (kWh/t) [math]\displaystyle{ F_{80}\text{ (}\rm{\mu}\text{m)} }[/math] is the 80% fraction passing size of the feed (µm) [math]\displaystyle{ P_{80}\text{ (}\rm{\mu}\text{m)} }[/math] is the 80% fraction passing size of the product (µm) [math]\displaystyle{ \text{Dry grinding} }[/math] indicates if the mill is dry grinding [math]\displaystyle{ \text{Open circuit} }[/math] indicates if the mill is operating in open circuit [math]\displaystyle{ \text{Control fraction passing} }[/math] is the product size control reference fraction passing value (frac) [math]\displaystyle{ D\text{ (m)} }[/math] is the mill diameter (m) [math]\displaystyle{ L\text{ (m)} }[/math] is the mill length (m) [math]\displaystyle{ \text{Rod mill} }[/math] indicates if the comminution device is a rod mill [math]\displaystyle{ \text{Rod mill only circuit} }[/math] indicates if the circuit includes a rod mill only [math]\displaystyle{ \text{Closed circuit crushing} }[/math] indicates if the feed is prepared with closed circuit crushing [math]\displaystyle{ W }[/math] is the operating work index (kWh/t) [math]\displaystyle{ \mathit{EF1-8} }[/math] are efficiency factors applied to the calculation of operating work index.

Figure 1. Example showing the selection of the Parameters (blue frame), and Results (light blue frame) arrays in Excel.

See also

• Comminution Circuit Specific Energy (Morrell)