Spectrum 21

COMMINUTION
HANDBOOK

Edited by Professor Alban Lynch

COMMINUTION
HANDBOOK
Edited by Professor Alban Lynch

The Australasian Institute of Mining and Metallurgy

Spectrum Series 21

Published by:
THE AUSTRALASIAN INSTITUTE OF MINING AND METALLURGY
Ground Floor, 204 Lygon Street, Carlton Victoria 3053 Australia
 © The Australasian Institute of Mining and Metallurgy 2015

No part of this publication may be reproduced, stored in a retrieval system or

transmitted in any form by any means without permission in writing from the publisher.

The Institute is not responsible as a body for the facts and opinions
advanced in any of its publications.

ISBN 978 1 925100 38 9

Desktop published by Kate Hatch and Claire Stuart for

The Australasian Institute of Mining and Metallurgy

Index prepared by:

Russell Brooks

Front cover images:

Top: courtesy Outotec (see Figure 5.1).
Middle: stock image of an underground grinding mill.
Bottom left and middle: courtesy Magotteaux
(see Figure 7.3 and Figure 9.16).
 Foreword
Alban Lynch is that rarest of combinations: a consummate technologist, a visionary leader
and a clear and persuasive communicator. This book is the latest exemplar of his skills.
Like the best developments, we didn’t know we needed it until we saw it. Now it seems
indispensable.
There is a place for deeply specialist (but rather turgid) texts; for specific-topic
technical papers; and for the ubiquitous Google searches and Wikipedia references.
But where was the handbook for the whole field of comminution – one authoritative
reference source for experts, yet an accessible tool to those new to the field? Who could
convince a list of esteemed but busy experts to volunteer their time; who could link
their individual contributions with insight and eloquence, to make the whole speak
cohesively and more clearly than the sum of its parts? Who else but Alban Lynch?
Just as in his career, traditional boundaries were no obstacle to Alban’s vision for this
book. He assembled experts from all fields of comminution. Most ‘mineral processors’
think of grinding as wet grinding of mineral ores. On the first page Alban gently
reminds us that more than twice this tonnage of cement and coal is subjected to
fine dry grinding. So this text includes contributions on the whole array of crushing,
grinding and classification equipment used to comminute the wide range of materials
demanded by our communities. Of course, the discussion would not be complete
without the explanations of sizing techniques, classification, testing and scale-up
methods, mineral liberation, circuit design, process control, circuit practice and recent
technology developments. By grasping the entire field, we are encouraged to seek new
opportunities by looking outside our personal and professional silos. It should haunt
us that more efficient devices such as high-pressure grinding rolls and tower mills were
common in dry grinding at least 25 years before they were discovered for ore grinding.
This book may help ensure that we don’t let that happen again.
Like Alban, the contributors to this book are dedicated to improving the efficiency of
meeting society’s needs. This is vital work. On the first page we are reminded that the
comminution of ores, cement and coal consumes around three per cent of the world’s
electrical energy, and that society will demand another 25 per cent of these materials by
2040. The energy requirement will increase more than that. Mineral ores are becoming
both lower grade and finer grained, so to produce one tonne of metal we will need to
process more tonnes of rock, and many of those tonnes will require finer grinding. Unless
something changes, the additional 25 per cent product may require closer to double the
energy used in 2010. That is the problem. Chapter 1 concludes by reminding us of the
opportunity: the theoretical energy efficiency of the most commonly used equipment is
still only five per cent.
 This challenge for current and future engineers is clear. Achieving step changes in
comminution efficiency won’t be easy. But it is our job, and society needs us to do it. If we
don’t, who will?
I recommend this text as the starting point for our quest, and Alban’s vision and tireless
work to assemble it as the inspiration.
Joe Pease FAusIMM
 Preface
Comminution is the process in which solid materials are reduced in crushing and grinding
circuits. Comminution machines are the equipment in which the process is carried out.
Billions of tonnes of ore, cement and coal pass through comminution processes annually
and these tonnages are increasing. To meet the rapid growth in demand, significant
advances have occurred in the design and construction of equipment, which have been
mainly due to improvements in energy and materials technologies. Some that have been
adapted to comminution include huge motors and gearless mill drives for the immense
rotating mills, and composite materials for protective linings to minimise breakdowns
due to wear.
In this book the processes and machines involved in modern-day comminution are
discussed, including the ancillary techniques used for the design, control and optimisation
of circuits. Because of advances in comminution technology and the growing population
and demand for materials, the process is now so widespread and intensive that
comminution is one of the technologies on which civilisation depends on a daily basis;
for example, grinding coal for power generation, clinker to make cement for buildings,
and grains to make bread.
Comminution is mainly carried out by mechanical devices, the exception being the first
stage in most mining operations when it is carried out by blasting to extract broken rock
from the rock mass. Blasting is an energy-efficient and cost-effective way of preparing
ores for the crushing and grinding circuits in which the fine particles that are required
for mineral liberation and separation are produced. Blasting is not discussed in this book,
except to mention the link that exists between blasting intensity and the size of the rock
fragments that comprise the feed to semi-autogenous grinding (SAG) mills.
The main processes in comminution are breakage and classification. Breakage is a size
reduction process and it occurs by impact, compression, shear or attrition. Classification
is a size separation process that occurs by screening or by the differential movement of
particles in liquids or gases. Closed circuits, which involve recycling the coarse fraction
from the classifier back to the mill, are commonly used for comminution processes. It is
important to optimise both the sizes of machines in the circuits at the design stage and
the operating conditions of the circuits at the production stage.
There are four themes in discussing comminution in this book:
1. the characteristics of the material to be processed (chapters 2 to 4)
2. the equipment available for processing (chapters 5 to 10)
3. circuit design (chapters 12 and 16)
4. circuit optimisation and control (chapters 11 and 13–15).
 In an effort to cover everything, the topics are discussed concisely and this means
that comments on some important issues have been curtailed or omitted. For further
information, the reader is referred to the symposia on comminution that are organised by
universities and engineering institutions.
The purpose of this book is to present comminution as it is today to those with the
responsibility of improving the technology in the future. The emphasis is on ores, but it is
hoped that there is sufficient discussion of cement and coal to encourage engineers in all
specialities to discuss progress jointly in the future.
There are many people who assisted in the compilation of this book and they are listed
in the following pages. In particular I wish to thank Hakan Dundar, who has contributed
much to several chapters of this book, both technically and mathematically, and has
provided continuing advice and comments. His responses were always fast and relevant.
Thank you for your assistance Hakan. I also wish to thank the AusIMM publishing team,
Stephanie Ashworth, Kristy Burt and Kelly Steele, for their patience, persistence and
dedication.
Professor Alban Lynch HonFAusIMM
 Contributors

Alban Lynch HonFAusIMM

Alban’s career in mineral processing began in 1954 at the Zinc Corporation in Broken Hill.
He then moved to the University of Queensland in 1958, where he worked as a research
engineer for the next 30 years. Amongst his achievements there was his involvement in
the first plant-based research project at Mount Isa Mines. Alban then became Foundation
Director of the Julius Kruttschnitt Mineral Research Centre from 1971 to 1988, where
he specialised in the modelling and control of processes. After that he was Head of the
Department of Mining and Metallurgical Engineering from 1988 to 1993, and then was
a Visiting Professor at universities in Brazil, Mexico, Malaysia and Turkey over a 15-year
period. As well as lecturing, Alban established research programs in these countries,
the most successful of which was in cement clinker grinding at Hacettepe University in
Turkey. This program has grown from a research group of one graduate student in 1999
to a staff of three along with ten graduate students in 2009. The program works closely
with the cement industry.
Alban’s publications include two books on mineral process simulation and control,
The History of Grinding written with Chester Rowland and more recently, the AusIMM-
published History of Flotation. He has also authored over 150 technical papers. Alban has
been the recipient of the AusIMM’s President’s Award and Institute Medal, the AIME’s
Robert H Richards Award and the SME’s Antoine M Gaudin Award. He has also received
the IMPC’s Lifetime Achievement Award and the Order of Australia, and is a member of
the International Mining Technology Hall of Fame (Comminution).

Katie Barns MAusIMM

Katie has worked in the minerals industry since 1994 in a variety of roles, including
flow sheet and plant development, design and commissioning followed by ongoing
optimisation of operations in both Australia and overseas. More recently Katie has
been with Glencore Technology over the past ten years (formerly Xstrata Technology)
as Strategy Manager for the IsaMill Technology business. Here her focus has been on
improving the overall energy efficiency of mineral processing operations in the whole
process chain. Katie has a degree in Chemical Engineering from the University of
Queensland and an MBA from Deakin University.

Dirk Bass
Dirk has been working in the field of instrumentation and control for over 20 years. In
the last 16 years he has specialised in optimising process control systems in a wide range
of industries including food and beverages, manufacturing and mineral processing. Dirk
joined PanAust Ltd in November 2011 as the Senior Advisor – Process Control, where his
current role is to develop the advanced control solutions and process control standards
for the company. He believes that mineral processing plants should be highly automated,
elevating the control room operator’s role from adjusting set points to ensuring process
objectives are achieved.

Duncan Bennett MAusIMM

Duncan commenced his metallurgy career with copper, gold and bismuth at North
Broken Hill Peko’s Warrego operations in the Northern Territory (NT), followed by time
at WMC Resource’s Kambalda nickel concentrator. He then spent four years working
in gold plants in southern Western Australia (WA) with Resolute Ltd. After periods
at Queensland Nickel and managing a private CIP (clean-in-place) carbon-cleaning
business in WA, Duncan moved to Tasmania for eight years where he worked in mill
and general management positions at the Renison Bell and Mount Bischoff tin mines,
including a two-year period at Australian Paper’s Burnie mill. Following a brief foray
back in gold at Hill End in New South Wales (NSW) and Union Reefs in the NT, Duncan
has been with PanAust Ltd since 2010 as Principal Metallurgist overseeing metallurgical
and process development of new and existing copper and gold projects.

Hakan Benzer
Hakan is the Head of Mining Engineering at Hacettepe University, where he also attained
his PhD, and is Director of its International Mining Center. He leads the Hacettepe
Comminution Group and is a member of the Global Comminution Collaborative (GCC),
a research collective addressing the sustainability of comminution in the mining
industry. Hakan has been a visiting academic at JKMRC at the University of Queensland,
and is currently running several projects for the cement and minerals industry. His main
interest is on comminution and classification circuits, where his major research topic is
the modelling of dry grinding and classification circuits.

Alain Broussaud
Alain holds a Master’s degree in Physics and an Engineering degree from the School of
Mines in Nancy, France. He is currently Vice President, Virtual Plant Simulation program
at Metso Minerals and co-founded Metso Cisa (originally Cisa) in 1990. Cisa developed,
marketed and implemented original optimising technology for the mineral processing
industry, including vision systems, acoustic sensors and advanced process control
systems. While being Cisa CEO for 23 years, Alain remained involved in technical matters
and contributed to advanced control projects worldwide. His earlier assignments
include being Plant General Manager at a phosphate company in Senegal, and Deputy
Head of BRGM’s Mineral Technology Department in France, where he created the
UsimPac simulation software package in mineral processing in 1986.

Marcos Bueno GAusIMM

Marcos has eight years’ work and research experience in mining and mineral processing
engineering with in-depth knowledge of the design and optimisation of comminution
circuits and geometallurgy. He has carried out extensive comminution circuit surveys
and pilot plant campaigns in Australia and internationally, and has been involved
in technical studies and process design engineering projects related to most key
mining commodities including gold, copper, iron ore, aluminium, nickel, platinum and
phosphates.

Don Burgess FAusIMM

Don immigrated to Australia and joined Allis Chalmers in 1966, working in the design
office. His interest in crushers and grinding mills was heightened after meeting Fred
Bond on tour in Australia in 1968. Don later became Allis Chalmers’ crushing and
grinding specialist where he has been involved in the design and application of over 300
grinding mills in Australasia, Africa and Europe. In 1994 Don set up his own consulting
business specialising in comminution systems, which involved mill selections, JKSimMet
simulations and design innovations such as fitting discharge grates in 15-foot diameter
rod mills. He has written several technical papers on grinding including one describing an
accurate method of calculating AG/SAG specific energies, an example of which is in this
publication.

Hakan Dundar
Hakan is currently an Assistant Professor in the Department of Mining Engineering
at Hacettepe University in Turkey, where he received his Bachelor, Masters and PhD
degrees in mining engineering. While comminution was the main focus of his Masters
and PhD, he also studied cement grinding (Masters) and high-pressure grinding rolls
in the minerals industry (PhD). Hakan specialises in comminution circuit design and
modelling, and is skilled in the use of modelling and simulation tools to design and
optimise a crushing and grinding circuit, as well as model development. Energy saving
and capacity improvement in a comminution circuit form his main areas of interest.

Udo Enderle
Udo graduated in Mechanical Engineering from the Technical University Munich where
he specialised in design and development. He later joined Netzsch Feinmahltechnik the
same year, and managed projects for paint and ink production plants in Europe, China and
Russia. Udo then spent several years as Head of Mill Design and was later Technical Director
for Netzsch. Since July 2009 he has been Managing Director of Netzsch Feinmahltechnik
where his focus is on technology and development. Udo holds over 100 patents and was
co-inventor of the IsaMill.

Cathy Evans
Cathy is a mineral processing engineer with over 30 years’ experience in the minerals
industry. Since graduating in Mineral Technology from Imperial College, London, she
has worked as a metallurgist in mines in South America and Australia and as an industry-
focused research metallurgist at the Julius Kruttschnitt Mineral Research Centre
(JKMRC) at the University of Queensland. During her career at JKMRC she has applied
her knowledge of processes and ore mineralogy to develop practical methods for
optimising mineral processing operations. Understanding mineral liberation is the key
to optimising comminution and separation processes as an integrated process chain,
and through Cathy’s consulting and research for industry partners while measuring and
modelling mineral liberation, she has developed a broad range of expertise in this area.

Matthew Fitzsimons
Matthew studied a Bachelor of Mechanical Engineering (Aeronautical) at the University of
the Witwatersrand, Johannesburg and graduated in 2001 with four distinctions. He began
his working career at the CSIR in the Defence Aeronautics division where notable
achievements include project managing the upgrade of the High Angle of Attack (HAOA)
capability in the Transonic Wind Tunnel Facility and being nominated for a Technological
Scientific Excellence Award as part of the Continuous Force Development and HAOA
Capability Testing Team. In 2008 he went to Murray and Roberts Steel as a Specialist
Engineer to manage research and development; this encompassed projects involving
product development, capital asset management and production optimisation. Matthew
has been at Multotec as Technical Manager for the past five years.

Bianca Foggiatto MAusIMM

Bianca has eight years of experience in metallurgical and process engineering. She
completed both her Mining Engineering and Masters in Minerals Engineering degrees
at the University of Sao Paulo, where she specialised in the comminution of Brazilian
iron ores. Bianca’s expertise covers management and planning of laboratory test work,
coordination of plant/pilot plant trials and surveys and process design/optimisation.
She has worked at HDA Servicos, a consulting company in Brazil, and with Votorantim’s
technology team where she oversaw all nickel operations and tailings recovery. She
is presently working as a process engineer at Ausenco and completing her PhD at the
University of Queensland’s JKMRC, specialising in comminution and circuit energy
efficiency.

Bodo Furchner
Bodo earned his degree in Process Engineering at the Technical University Munich. After
his studies he worked as a scientist at the Institute for Process Engineering in Munich,
where he undertook his Doctor’s degree. In 1987 he began work for Hosokawa Alpine
in research and development and in 1995 was appointed Manager of the Test Centre
Mechanical Processing. Since 1999, he has been General Manager of the Technical
Division.

Olivier Guyot
Olivier is currently Vice President of Metso Minerals Center for Advanced Technology
(MCAT), and before that was the General Manager of Metso-Cisa. He holds a degree in
Mining Engineering from the Ales School of Mines in France, and possesses 26 years
of experience in creating and delivering innovative technology for the minerals and
metallurgical industry, including modelling, simulation and advanced sensing. Olivier
created OCS© software, a leader in advanced control for mineral processing optimisation,
as well as a series of pioneering vision and audio-based sensors, VisioFroth™ and
VisioRock™.
Cathy Hewett
Cathy is a Materials Consultant Engineer in Perth, Australia and has over 18 years’
experience within the materials, mining and manufacturing spheres. She holds a PhD
in Engineering Science from Monash University, a Bachelor’s degree in Applied Physics
(RMIT University) and a Master of Business Administration (Deakin University). The
common thread in Cathy’s career has been the mitigation of erosive and abrasive wear
using innovative materials solutions alongside engineering design.

Rick Hughes
Rick is Managing Director and Principal Consultant of Microanalysis in Perth, Australia. He
graduated from Robert Gordon University in Aberdeen, Scotland with Honours in Physics,
and has over 27 years’ experience in the industry in all facets of particulate characterisation
and sizing. Rick specialises in forensic particulate science, assisting clients from a broad
spectrum of areas to identify and understand their particulate matter and how this
impacts on their processes.

Cliff King MAusIMM

Cliff is currently the Principal Process Engineer at Preplab Testing Services in Rockhampton,
Queensland. Graduating from the University of Queensland in 1973, he worked in base
metals at Cobar/Broken Hill from 1974 to 1979 before joining the coal industry and
working at Moura, Riverside and Curragh coal mines. Cliff then moved into consulting in
1997, working at Burton, North Goonyella, Moranbah North and Cameby Downs mines.

Deon Kok
Deon obtained his Metallurgical Engineering degree from the North-West University,
South Africa in 1993 and Master’s degree in Business Leadership from the University of
South Africa in 2003. He worked in various industries and capacities (gold, manganese,
steel) before joining Newmont Ahafo Ghana in 2008. He is currently the Process and
Commissioning Manager for the Ahafo mill expansion project.

Greg Lane FAusIMM

Greg has around 30 years’ experience in operations, engineering and design, and study
and project management, with an industry-leading knowledge of concentrator design. In
his current role as Chief Technical Officer of Ausenco, he provides specialist technical and
project development expertise on major projects for clients. The author of more than 40
publications on different aspects of minerals processing and project development, Greg
is a highly sought-after technical expert and world leader in plant design, particularly
comminution and flotation circuits.

Geoffrey Legrand
Geoffrey graduated from the Ecole Nationale Supérieure de Géologie in Nancy, France, and
joined Metso in 2007. He was first involved in several research and development projects
related to the VisioFroth™ technology and then in advanced process control projects
covering grinding, crushing, flotation, thickening and pelletising. Geoffrey has been
involved in projects for companies such as Rio Tinto, Newmont and AngloGold Ashanti in
more than 15 countries. He has extensive expertise in MCAT advanced sensors including
VisioFroth™, VisioRock™ and AudioMill™, and manages the APC engineering team based
in France, which supports Europe, the Middle East and Africa, as well as the hardware
production team providing vision and audio advanced sensors around the world.

Aubrey Mainza
Aubrey has a great deal of experience in the area of comminution and classification. In
addition to a year at Zambia Consolidated Copper Mines, he has spent more than 17 years
working in the comminution research group in the Centre for Minerals Research at the
University of Cape Town. Aubrey has also participated in the design and optimisation of
many mines including all the major platinum and gold mines in Africa and overseas. He is
currently working as an Associate Professor in the Department of Chemical Engineering
at the University of Cape Town and is the Head of Comminution Research and Deputy
Director for the Centre for Minerals Research.

Eddie McLean FAusIMM

Eddie is the Manager of Minerals Consulting at Ausenco, which is based in Brisbane. He is
a graduate in Metallurgy from the University of Queensland and a Fellow of the AusIMM.
At Ausenco since 2002, his roles have included managing regional and national groups of
process engineers and providing technical support to international group offices. Eddie’s
expertise encompasses a range of process design and engineering activities, with much
experience gained in comminution, beneficiation and hydrometallurgical extraction
in the following commodities: precious metals (gold, silver), base metals (copper, lead,
nickel, zinc), mineral sands and industrial minerals.

Gunter Metzner
Gunter started his career with the Measurement and Control Division at Mintek in South
Africa as part of the team that implemented the first successful multivariable controllers
for milling. He joined the De Beers Group in 1994 to build a research group focusing on
automation, monitoring and diagnostics, and was instrumental in developing an expert
control system that successfully increased throughput and stability in diamond recovery.
Gunter has been the Manager of Process Research and Development of DebTech, has
spent some time with the Advanced Systems Group of SGS and is now the Advanced
Process Control Regional Manager for Australasia at Metso’s Minerals Centre for Advanced
Technology (MCAT), where he is involved in technologies for the control and optimisation
of minerals processing plants.

Chris Morley
Chris has 43 years’ experience in design, commissioning, operation and control of
metallurgical and materials-handling plants covering diamonds, coal, gold, silver, iron
ore, vanadium, base metals, platinum and uranium. He has experience in Australia and
internationally, and has established a recognised level of expertise in the engineering of
comminution circuits, especially in the application of high-pressure grinding rolls (HPGR)
systems for several commodities. Working on the Boddington feasibility study, Chris was
involved in the development of a practical high-capacity HPGR-based circuit – one of the
first of its kind – that demonstrated project viability and enabled project execution.

Steve Morrell
Steve is a minerals processing engineer with over 30 years of specialist experience in
comminution, where he has been involved with the design and optimisation of most
major comminution circuits in the world. In 1980 he graduated with a Bachelor's degree
(Honours) in Engineering Science from Imperial College, London, majoring in Metallurgy
and spent the next seven years working on mines throughout Africa. He subsequently
moved to Australia and completed Masters and Doctorate theses in grinding mill
simulation and power draw modelling at JKMRC. Up until 2000, when he left JKMRC to
start his own consultancy (SMCC Pty Ltd), Steve oversaw world-leading research projects
such as the AMIRA P9, High-pressure Grinding Rolls, Fine Grinding and Mine-to-Mill
programs. In 2003 he founded SMC Testing to license the SMC Test® that he developed.

Joe Pease FAusIMM

Joe has worked in the minerals industry since 1982 in a variety of research, operations
management, and technology development roles, including 20 years at Mount Isa copper
and lead-zinc concentrator and smelting operations. He was CEO at Xstrata Technology
for 12 years, and has continued his focus on improving processing efficiency with roles
as CEO of the Cooperative Resource Centre for Optimising Ore Extraction (CRC ORE)
and Board positions with AMIRA, JKMRC and the Ian Wark Institute. Joe is Chairman of
CEEC (Coalition for Eco Efficient Comminution), and is on the Steering Committee of the
Minerals Tertiary Education Council.

Marc Revalor
Marc received his PhD in Engineering Science (design, optimisation and control of rolling
mills) in 2008, and also holds an Engineering degree from the Ecole Centrale in Lyon and
a Master’s degree in Industrial Automation. He has had four years’ experience in process
modelling and control (rolling mills, steel making) at Alcan and ArcelorMittal in France,
before joining Metso Minerals Center for Advanced Technology (MCAT) in January 2009.
Since then, Marc has been involved in advanced process control and modelling projects
worldwide, particularly for concentrators and induration plants. As Technical Expert
for Advanced Process Control and Modelling, he spent a year seconded at Rio Tinto’s
Processing Excellence Centre in Brisbane, and now leads real-time dynamic process
modelling efforts for Metso MCAT.

Etienne Roux
Etienne graduated from the University of Stellenbosch in South Africa, then joined Anglo
American Base Metals in 2003 before going to Newmont Mining Corporation in 2010.
He was responsible for the client-side implementation of the Advanced Process Control
system for the gold mill at Newmont’s Ahafo Project in Ghana, and has been involved
in technical and production roles in commodities such as zinc, copper, lead, titanium
and gold in several countries. Etienne is currently Senior Operations Superintendent at
Horsehead Corporation’s Mooresboro zinc project, where he manages operations of the
Waelz oxide leaching, solvent extraction, bleed treatment and lead recovery plants, as
well as technical support for the zinc electrowinning and casting operations.

John Russell MAusIMM

John attained tertiary qualifications in Mechanical Engineering at the Queensland
Institute of Technology (now QUT) and then joined Mount Isa Mines (MIM) in 1980,
where he spent five years gaining experience in copper and lead smelters and
concentrators, and associated underground mines. Leaving MIM in 1985, he formed
Russell Mineral Equipment (RME), a niche-market engineering enterprise whose core
business is the investigation, design, build and commissioning of specialised mineral
processing equipment for industry. In 2007, John was awarded the Canadian Mineral
Processors Art McPherson Medal for contribution to the advancement of comminution,
and in 2009, an Honorary Doctorate in Engineering from the University of Southern
Queensland. In 2014, he was presented with the Mineral Industry Technique Award by
the AusIMM.

Glenn Schumacher MAusIMM

Glenn is currently Chief Engineer, AGL Energy Group Operations and has responsibility
across its mining and major electricity-generating operations. Prior to joining AGL in late
2013, he was General Manager of NRG Gladstone Operating Services for six years, where
he was responsible for the overall management and leadership of Queensland’s largest
single power station. Glenn has held a number of positions in the electricity generation
industry as well as other areas such as technical services (Tarong Energy Corporation),
production (International Power, Hazelwood Power Station) and maintenance (SILCAR). He
holds a Bachelor of Engineering (Mechanical), Master of Engineering (Power Generation),
Master of Business Administration and Doctor of Engineering (honoris causa).

Spike Taylor
Spike studied a Bachelor of Science (Engineering Extractive Metallurgy) at the University
of the Witwatersrand, Johannesburg and graduated in 1977. He then worked for De Beers
for seven years before moving through the Graduate Metallurgist program and working
in research and development. This was followed by three-and-a-half years at Debswana
Jwaneng commissioning and operating the main treatment plant as an Assistant Plant
Superintendent. Spike has now been at Multotec for over 30 years: the first 18 years in
the sales and marketing of polyurethane and wedge wire screening media and trommel
screens for Multotec Manufacturing, followed by Sales Director for Multotec Rubber from
2002 until 2009 and then Managing Director.

Walter Valery FAusIMM

Walter is Metso Global Senior Vice President of Technology and Innovation. He is a
comminution expert and leader in the industrial implementation of Mine to Mill,
comminution process characterisation, modelling, simulation and optimisation of mineral
processing operations. Walter’s contributions are based on 30 years of fundamental
research, industrial experience and pioneering transformational consulting, and he has
published and presented more than 100 technical papers. He is one of the pioneers in
ore tracking from the blast to the mill and development of geometallurgical systems for
integration and optimisation of mine and processing plants. Walter is currently working
on the development of resource and eco efficient mining processes to extract minerals
more efficiently.

Peter Walker MAusIMM

Peter is a metallurgist with over 30 years’ experience in the design, commissioning
and operation of processing plants and general management of operations in Europe,
Australasia and South America. In recent years he has been responsible for the feasibility
and development of greenfield and brownfield projects in Thailand, Laos and Chile. Peter
has worked for a number of engineering groups, as well major and mid-tier operating
companies with commodities such as lead/zinc, uranium, coal, nickel, copper and
precious metals. He has specific experience in the design and operation of large-scale
comminution circuits involving autogenous and semi-autogenous grinding.

Thomas E Warne
Tom is the President of Schutte-Buffalo Hammermill in Buffalo, New York, who manufacture
over 250 different models of size-reduction equipment. He served as General Manager of
Buffalo Hammermill Corp from 1991 to 2001, and became President of Schutte-Pulverizer
in 2001 where he spearheaded the acquisition of his former employer Buffalo Hammermill
Corp later that year. In 2004, Tom purchased the assets of the combined companies along
with partner James N Guarino. As President and CEO of Schutte-Buffalo Hammermill, he
guided the company to over 300 per cent growth with sales to more than 50 countries
worldwide. In December, 2014 they sold the company, though Tom continues to serve in
the role of Company President.

Mark V Weaver
Mark has been a registered professional engineer since 1989. He earned his Bachelor
of Science in Mechanical Engineering in 1984 and a Master of Engineering from the
University of Alabama, Huntsville, in 1991 while working as Spacelab Mission Lead for the
USMP-series of Spacelab Missions. He joined Polydeck Screen Corporation as Engineering
Manager in 2005, served as Director of Engineering and is now the Director of Research
and Development. During his tenure as Engineering Manager, Mark developed new
designs for trommels now used throughout the world that utilise modular synthetic
screening media.

Jobe Wheeler
Jobe has a Bachelor of Science in Mechanical Engineering from the University of
Buffalo, New York. His industrial experience in manufacturing began at Motorola,
concentrating on equipment maintenance/reliability and process improvements. He
entered the mineral processing industry in 2007 with Derrick Corporation, a leader in
fine-screening technology, with a focus on iron ore processing and comminution circuit
improvements. Since starting at Derrick, Jobe has worked on comminution projects in
the Minnesota Iron Range, Labrador Iron Trough (Canada) and several countries around
the world with a focus on improving classification efficiency and product grade, and
increasing recovery of valuable minerals.

Bob Yench
Bob originally trained as an electrical engineer in Melbourne before moving to Mount
Isa Mines in 1966 where he commenced work as an instrument engineer. He spent the
following 48 years working in instrumentation and process control, primarily in the mineral
processing industry. In 1997 Bob became the inaugural CEO and Managing Director of
MIPAC Engineering (later MIPAC Pty Ltd), a Brisbane-based specialist process control
group. His many roles in the industry over this period have included design, installation
supervision, commissioning and maintenance of process plant control systems. Bob
has had a long-term interest in promoting greater process control knowledge for plant
operators.
 Acknowledgements

STEERING COMMITTEE

Alban Lynch HonFAusIMM, Editor

Diana Drinkwater MAusIMM, Program Director – Accelerated Development
Portfolio, JKTech Pty Ltd, Brisbane, Australia
Peter Tilyard FAusIMM(CP) Metallurgist, Tilyard Metallurgical Services,
Melbourne, Australia

CONTRIBUTORS
Along with the primary contributors listed in the previous pages, the people listed below
assisted with the compilation of this book by providing contributions, comments and
advice. Their involvement in this project is greatly appreciated.
While contributions came from many sources the opinions presented in this book are the
responsibility of the Editor.

Geoffrey Barnett Managing Director, Minco Tech Australia Pty Ltd, Cardiff,
Australia
Miron E Boris Process and General Audits, Thrane Teknikk CJSC, Electrostal
(Moscow), Russia
Rob Coleman MAusIMM, Head Mineral Processing Solutions, Outotec
South-East Asia Pacific, Brisbane, Australia
Eddie De Rivera Managing Director, MIPAC Pty Ltd, Brisbane, Australia
Chris Greet FAusIMM(CP), Manager Minerals Processing Research,
Magotteaux Australia Pty Ltd, Adelaide, Australia
Yaqun He Mineral Processing Manager, China University of Mining and
Technology, Jiangsu, China
Rajiv Kalra MAusIMM, Global General Manager, CITIC Heavy Industries,
Sydney, Australia
Amit Kumar Consultant / Mineral Processing Engineer, Vancouver,
Canada
 Suzanne Lynch-Watson MAusIMM, General Manager, Process and Grinding,
Multotec, Brisbane, Australia
Jeff McKay Manager, Expert Systems Global, Metso Mineral Center for
Advanced Technology (MCAT), South Jordan, Utah, USA
Mark McVey Managing Director, MMD Australia Pty Ltd, Narangba,
Australia
Gavin Pasin Regional Product Manager Asia Pacific – Mill Lining
Solutions, Metso Minerals, Brisbane, Australia
Marc Piccinin Grinding Process Engineer, The Cement Grinding Office,
Verona, Italy
Jerome Portal Export Sales Manager, Fives FCB, Lille, France
Rolf Steinhaus Sampling Specialist, Director – Multotec Process Equipment,
Kempton Park, South Africa
Ron Wiegel Mineral Processing Consultant, Lakeland, Florida, USA
Heather Wilt Director of Marketing and Communications, McLanahan
Corporation, Hollidaysburg, Pennsylvania, USA
Peter Wulff TowerMill Business Development, Eirich Group
Headquarters, Hardheim, Germany
Jawahar M Yardi Cement Engineer, Brisbane, Australia

REVIEWERS
We wish to thank the following reviewers for their helpful feedback.

Chris Bailey MAusIMM, Advisor – Processing and JKSimMet Product

Manager, JKTech, Brisbane, Australia
Ted Bearman Director, Bear Rock Solutions, Perth Australia
Johannes Cilliers Chair of Mineral Processing and Head of Department of
Earth Science and Engineering, Royal School of Mines,
Imperial College, London, UK
Dean David FAusIMM(CP), Technical Director – Process, Amec Foster
Wheeler, Perth, Australia
Bill Johnson FAusIMM(CP), Senior Principal Consulting Engineer,
Mineralurgy and Adjunct Professor, Julius Kruttschnitt
Mineral Research Centre, University of Queensland, Brisbane,
Australia
Emmanuel Manlapig Senior Processing Manager, Julius Kruttschnitt Mineral
Research Centre, University of Queensland, Brisbane,
Australia
Bill McKeague Business Development Manager Asia Pacific, MineSense
Technologies and Owner, Adaptive Solutions, Brisbane,
Australia
Brian McNab MAusIMM(CP), Principal Process Engineer, Amec Foster
Wheeler, Perth Australia
Rob Morrison MAusIMM, Chief Technologist, Julius Kruttschnitt Mineral
Research Centre, University of Queensland, Brisbane,
Australia
Andrew Newell MAusIMM(CP), Executive Consultant, Processing,
RungePincockMinarco, Brisbane, Australia
Sam Palaniandy Senior Research Fellow, Julius Kruttschnitt Mineral Research
Centre, University of Queensland, Brisbane, Australia
David Royston Principal, Royston Process Technology, Brisbane, Australia
John Starkey President and Principal Consulting Engineer, Starkey &
Associates Inc
Walter Valery FAusIMM, Global Senior Vice-President, Metso, Brisbane,
Australia
Elaine Wightman Senior Research Fellow, University of Queensland, Brisbane,
Australia
Bob Yench Business Development Consultant, MIPAC, Brisbane,
Australia
 Sponsors
The AusIMM would like to thank the following sponsors
for their generous support of this voume.

Principal Sponsor

Major Sponsor

General Sponsors
 Constancia copper-molybdenum project, Peru

Ausenco is recognised for

its expertise in all aspects of
comminution.
Ausenco provides process Ausenco’s leading-edge • We utilise other recognised
design, engineering, project comminution experts utilise comminution programmes
construction and asset in-house modelling and and methodologies such as
management services to the simulation programmes to JKSimMet to benchmark and
global resources and energy provide practical solutions for cross-reference performance
industries. comminution circuit design, and outputs.
equipment selection and sizing.
Ausenco’s skilled professionals Their technical efforts are • We take metallurgical test
offer expertise across all phases supported by proven layout and work data, ore resource
of a project lifecycle: test work for engineering design expertise to models and mine schedules
ore characterisation; concept to achieve cost-effective, robust and to design and install circuits
feasibility studies; preliminary to low-risk comminution circuits. that will attain a specified
detailed engineering; plant start- throughput.
up to full commissioning and Ausenco’s assurances to
ramp-up; asset management and the minerals industry for • We commission and provide
optimisation services. comminution circuit design operations support to
and engineering: enable our clients to achieve
The comminution circuit is pivotal optimised performance.
to a project’s success by several • We have developed a
measures: capital cost, operating proprietary, power-based With full-service design and EPC/
cost, energy efficiency, operability, simulation model called EPCM project delivery offices
maintainability and ability to “Ausgrind”, to facilitate circuit that service the minerals and
meet throughput demands in design, equipment sizing and energy industries from major
response to variable ore types selection. cities in Australia, North America,
from the mine. South America and South Africa,
• We are experts in the Ausenco is well positioned to
application of recognised meet the global needs and
ore characterisation challenges of our clients.
methodologies, including
JKDWT, SMC, SPI, Bond,
and Starkey.

www.ausenco.com
Major sponsor profile
JKTech
JKTech Pty Ltd is the technology transfer company for the Sustainable Minerals Institute
(SMI) at The University of Queensland, commercialising research outcomes from the
Centres of the SMI, including the Julius Kruttschnitt Mineral Research Centre.
From JKTech’s formation in 1986, comminution has been the cornerstone of its suite of
product and service offerings, including comminution consulting, JKSimMet simulation
software, breakage characterisation and training. Design and optimisation studies have
been undertaken in hundreds of mineral processing plants around the world, thereby
developing an extensive global database.
JKTech’s consulting services now utilise specialist JKTech software, equipment and
methodologies across comminution, flotation, mineralogy, mining and geometallurgy,
supported by laboratory testing and training courses.
Operating from its Australian head office in Brisbane, JKTech has subsidiary companies
in Chile and South Africa and representatives worldwide.
 Contents

Chapter 1
Comminution – An Overview ....................................................................................... 1

Chapter 2
Mineral Liberation ..........................................................................................................11

Chapter 3
Particle Measurement Techniques............................................................................25

Chapter 4
Ore Comminution Measurement Techniques ......................................................43

Chapter 5
Tumbling Mills..................................................................................................................61

Chapter 6
Compression Machines ................................................................................................79

Chapter 7
High-speed Impact Mills ..............................................................................................99

Chapter 8
Stirred Mills .................................................................................................................... 107

Chapter 9
Mill Liners ........................................................................................................................ 125

Chapter 10
Classifiers ........................................................................................................................ 145

Chapter 11
Comminution Circuits for Ores, Cement and Coal ........................................... 167

Chapter 12
Milling Circuit Calculations....................................................................................... 191

Chapter 13
Modelling Comminution Circuits........................................................................... 215
Chapter 14
Process Control ............................................................................................................. 227

Chapter 15
Case Studies of Control Systems ............................................................................ 245

Chapter 16
Circuit Design ................................................................................................................ 265

Glossary ................................................................................................................................. 303

Index ....................................................................................................................................... 309