A guide to maximising ball mill circuit classification system efficiency (CSE), for operators and equipment designers

K M Bartholomew, R.E.McIvor and O Arafat

14thAusIMM Mill Operators’ Conference, 29-31 August 2018, Brisbane, Australia

USA

ABSTRACT

It is well known in the industry that good classification system performance is vital to efficient ball mill circuit

performance. But what is meant by good classification system performance, and how is it achieved?

Unfortunately, the perceived complexity of classification systems, and the day-to-day time demands placed

on the practicing metallurgist, all too often put the low-hanging fruit of classification system optimisation in

the ‘I’ll do it later’ basket. Additionally, lingering confusion about basics such as the relationship between

circulating load ratio and ball mill circuit performance makes the optimisation objective seem nebulous to

both plant metallurgist and designer.

Some of this confusion can be eliminated by taking a step back from the overwhelming detail of sharpness of

separation curves, circulating load ratios, cyclone feed pressures, vortex and apex sizes etc, and focusing on

the purpose or function of the classification system – to apply mill power to particles that need further size

reduction! The classification system efficiency (CSE) metric captures how well the classification system is

performing its function with two quick and easy size distribution analyses.

Once CSE is understood and implemented as the optimisation criteria, well-tested methods for improving

CSE can be implemented and quickly measured at plant scale to give confidence that the right change was

made.

This paper will describe CSE and how it is measured in practice. Next, a guide for improving CSE through

manipulation of design and operating variables in the classification system will be provided. Examples and

case studies will illustrate the gains in ball mill circuit efficiency that can be achieved by maximising CSE.

 

AUTHOR DETAILS

K M Bartholomew (1), R.E.McIvor (2) and O Arafat (3)

  1. MAusIMM, Senior Metallurgist, Metcom Technologies, Inc., Grand Rapids, Minnesota USA 55744. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

  1. Chief Metallurgist, Metcom Technologies, Inc., Grand Rapids, Minnesota USA 55744. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

  1. Project Metallurgist/Marketing Manager, Metcom Technologies, Inc., Grand Rapids, Minnesota USA 55744. Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

 

ACKNOWLEDGEMENTS

CEEC acknowledges and thanks The Australian Institute of Mining and Metallurgy for organising the 14thAusIMM Mill Operators’ Conference (MillOps 2018). 

Abstracts can be found at the MillOps 2018 website.

 

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