First Extractive Metallurgy Operators' Conference Proceedings 2005

173 Pages·2005·10.204 MB·English

First Extractive Metallurgy
Proceedings
Operators' Conference
7 - 8 November 2005
Brisbane, Australia
O The Australasian lnstitute of Mining and Metallurgy 2005
All papers published in this volume were peer reviewed prior to publication.
The lnstitute is not responsible as a body for the facts and opinions advanced in any of its publications.
ISBN 1 920806 39 3
Desktop published by:
Kristy Burt and Angie Spry for The Australasian lnstitute of Mining and Metallurgy
Printed by:
BPA Digital
11 Evons Street
Burwood VIC 3125
Foreword
On behalf of the Southern Queensland Branch of The AusIMM welcome to the First AusIMM
Extractive Metallurgy Operators' Conference.
The conference is intended to complement the highly successful and popular AusIMM Mill
Operators' and Underground Operators' Conference series, and become a regular feature on the
conference calendar.
The intention of the Conference is to provide a forum for extractive metallurgy operators to discuss
and present experiences in dealing with real processing issues and their solutions. The three main
aims of the Conference are:
to exchange practical information to assist operators in improving their plant's day to day
performance;
to introduce new processing concepts and stimulate debate about how to improve the industry
generally; and
to review past performance on the implementation of projects from an operator's perspective
with the aim of identifying what was done well and what needs to be done better in the future.
All papers have been peer reviewed in accordance with The AusIMM guidelines to ensure the
presentation and technical content is maintained at a high standard. We are confident that the
conference volume will serve as a valuable source of information for those seeking to understand
and to further improve plant performance.
On behalf of the organising committee I would like to thank everyone who has contributed to the
conference, particularly the authors, reviewers, sponsors, exhibitors, venue hosts and The AusIMM
conference team.
We hope you find the conference both enjoyable and technically stimulating, and look forward to
meeting you all at the second conference in this series.
Peter Hayes and Conference Organising Committee
Contents
Keynote Addresses
EducationandDevelopmentofExpertisefortheResourcesIndustry CSartain 3
DialogueWiththeDarkSide—GeologistsandMinersArePeopleToo TJNapier-Munn 5
Leaching and Solvent Extraction
PilotStudiesoftheRavensthorpeNickelProject’sPressureAcidLeach DWhiteandMMiller 9
SlurryHeater
DesignandCommissioningoftheSeponCopperPressureOxidation RSherrit,AGPavlidesand 21
Circuit BLWeekes
HydroCopper®—ANewMethodforTreatingCopperConcentrates LHaavanlammi,OHyvärinen 29
andEYllö
ImplementationofaNewLeachingApproachfortheTreatmentofKCGM GDeschênes,SEllis, 35
GoldFlotationConcentrate JMcMullenandMHabner
AnalysisofAgitationLeachingData—MethodsandInterpretation GMMiller 41
UraniumRecoveryFromHighlySalineInSituLeachSolutionsbyIon KSoldenhoffandJDavidson 47
Exchange
TheUseofAuRIX®100ResinfortheSelectiveRecoveryofGoldand AHGray,THughesand 53
SilverFromCopper,GoldandSilverSolutions JAbols
ImprovingPlantOperationsUsingSynergisticSolventExtraction CYCheng,KBBarnardand 59
TechnologyandOrganicMonitoring MDUrbani
DecreasingOperatingCostsandSolubleLossinCopper GMMillerandANisbett 67
HydrometallurgyWithUseofInnovativeSolventExtractionCircuits
PreciousMetalRecoveryViaElectrolysistoYieldaFilterableSludge COGaleandTWeldon 73
Smelting and Converting
TheClyde-WorleyParsonsProposalforaFlashFurnaceFeedSystem MEReed,PACockburn, 81
RCWest,CUJones,
BSnowdon,PEWalkerand
RCSims
SamplingandMeasurementsintheReactionShaftatOlympicDam FJorgensen,ACampbell, 87
RTaylorandBWashington
ImprovingBlisterTappingatOlympicDam DJenkinsandACampbell 95
TheNewAngloPlatinumConvertingProject PViviersandKHines 101
ModellingofSlagBlowinCopperPeirce-SmithConverters PTanandPVix 109
ThermodynamicsofConvertingHigh-ImpurityCopperMatte MDevia,MCernaand 117
JRapkoch
Peirce-SmithConverterMouthRedesignOverview NAyre 123
Process Improvement
DesignConsiderationsforSmelterGasHandling PSearle,JRapkochand 131
MDevia
ImprovementinAustralianBulkMinerals’IronOrePelletQualityand HPham,MDarby,FLovell 137
ProcessPerformance andBBurdett
PreventionofScalingandCorrosionofTitaniumAlloyHeatExchanger RWAllan 143
TubesattheRisdonElectrolyticZincRefinery
PipelineDesignCharacteristicsofSomeIndustrialPaste-LikeSlurries GRAddie,MRCarstens, 147
ASellgren,RVisintainerand
LWhitlock
Plant Support
Commissioning—TheInterfaceBetweenConstructionandOperations BBailey 155
AlkaliEmissionReductionandMeasurementatQueenslandAlumina TLeongandTConnor 163
Limited(QAL)
ControlSystemImprovementThroughAlarmReduction CWebsterandRWest 171
ProcessInformationManagementSystematMountIsa PMuza 179
Education and Development of Expertise for the Resources
Industry
1
C Sartain
ABSTRACT
The resources industry in Australia is currently facing a skills shortage that has seen vacancies for
skilled tradespeople such as electricians (Australian Government, 2004), and for industry-specific
professionals such as mining engineers and metallurgists, go unfilled. For example, research
suggests that the industry can only source about 70 per cent of new metallurgists needed
throughout Australia annually (JEEMI, 2005). Likewise, the national demand for graduates in
mining engineering is also outstripping the national supply (JEEMI, 2005).
In his address to The AusIMM’s First Extractive Metallurgy Operators’ Conference, Xstrata
Copper’s Chief Executive, Charlie Sartain, will discuss solutions to the skills shortage being
pursued by the resources industry, government, educational institutions and companies such as the
global resources group Xstrata.
Charlie will explain why partnerships between industry, government and educational institutions
are the key to successfully addressing the skills shortage. Ideally, these partnerships should be
pursued on two levels. The first is at a state-wide and national level. The second, is at an
inter-personal and site level, whereby resources company employees, teachers, trainers and others
work together to establish and promote pathways for young people to enter the industry and
encourage an enthusiasm for careers in the resources industry.
Some of the skills and training initiatives Charlie will discuss are Xstrata’s school-based
workplace training program, the Queensland Minerals and Energy Academy, the Queensland
Resources Council’s Different Directions careers initiative, Xstrata’s apprentice training scheme,
the Minerals Council of Australia’s Minerals Tertiary Education Council initiatives and Xstrata’s
co-funding of the Xstrata Chair of Metallurgical Engineering at the University of Queensland.
REFERENCES
Australian Government, 2004. National Skills Shortage List 2004 [online]. Available from:
<http://www.workplace.gov.au/workplace/Category/Publications/LabourMarketAnalysis/NationalSkillsShortage
List2004.htm>.
AustralianGovernmentDepartmentofEducationScienceandTraining,ChamberofMineralsandEnergyWestern
Australia,MineralsCouncilofAustralia,NationalInstituteofLabourStudiesFlindersUniversity,NCVER,2005.
Prospecting for Skills: The Current and Future Skill Needs in the Minerals Sector,NCVER, Adelaide.
JEEMI, Joint Industry/University of Queensland Taskforce, 2005. Engineering Education for the Minerals
Industry,Brisbane.
1. Chief Executive, Xstrata Copper, Level 9, Riverside Centre, 123 Eagle Street, Brisbane Qld 4001.
First Extractive Metallurgy Operators’ Conference Brisbane, QLD, 7 - 8 November 2005 3
Dialogue With the Dark Side — Geologists and Miners Are
People Too
1
T J Napier-Munn
ABSTRACT
We all live in professional silos – comfort zones, where we talk to like-minded people with the
same training, experience and view of the world. We note in passing the existence of other
disciplines, but they are tolerated rather than embraced. To the geologist, the metallurgist is a mad
scientist conjuring gold out of some foul solution about which the less said the better. To the
metallurgist, the geologist is a bearded, self-appointed sage who guesses what is under our feet by
sniffing the air, and drives a Land Rover badly. As to the view of mining engineers held by both
geologists and metallurgists, this is best left to the imagination. And of course we are all confused
bytheterm‘metallurgist’.Iamcalledametallurgistthoughmyskillsareinmineralprocessingnot
metal processing, but I can’t be called a mineralogist because that definition is already taken.
This presentation considers the differentiation of the professions, and why it is a good idea to
breakdowntheprofessionalsilos.Itconcentratesontheminesite,buttheprinciplesareapplicable
to the whole value chain including smelting and refining.
The planning and operation of the modern, complex, capital-intensive mine, refinery or smelter
needs the professions to work together to meet the expectations of shareholders and the wider
community.Sustainability isthekeytosuccess,andthisneedsasophisticated, integratedapproach
to managing the operation on the mine site. However, our universities still train our industry’s
professionals in silos, and the graduate’s early career structure generally does little to break down
these work barriers or professional prejudices. And the cost to our industry is massive.
About 12 yearsago, agroup of ‘metallurgists’atthe Julius Kruttschnitt Mineral ResearchCentre
(JKMRC) in Brisbane was discussing the potential for improving the throughput of large
autogenous and semi-autogenous (SAG) mills by feeding them with the right size distribution of
rocks(itturns out thatsizeiseverything inthisbusiness).Sincetheyweremetallurgists,theirview
was that the game is won or lost in the process plant; that’s where the value recovery and product
grade are achieved, and where the deficiencies of their geological and mining colleagues are
rectified. The solution clearly lay in persuading the mining engineers to create the right ROM size
in the first place. This, however, wasconsidered to be impossible because, well, it involved mining
engineers doing something smart. And, most telling, ‘miners never talk to mets on these mine
sites’. Then someone pointed out that neither did we, at the JK Centre.
The JK is an unusual R&D organisation in that it does work on both mining and mineral
processing under one roof. Of course we had followed the usual practice and put the miners and
processors in different offices. But in principle we could talk to each other. We just didn’t. This
was a profound discovery with a profound outcome. Before long we realised that the two
disciplines had much to learn from each other. The SAG mill discussion had arisen from a project
with an iron ore company to develop a method of predicting the particle size distribution from
small-scale winze blasting as an alternative to wide diameter drilling, for mine planning purposes.
The ultimate objective was to predict the particle size of the saleable lump and fine products
producedbythecrushingandscreeningplantsfromorefromdifferentpartsofthemine.Thiswork
led to the establishment of the highly successful AMIRA P483 ‘Mine-to-Mill®’project, which ran
for six yearsand in due course won The AusIMM Operating Techniques Award. P483 developed a
suite of tools for predicting and controlling fragmentation in blasting to optimise the comminution
performance of the processing plant. Other projects with individual mining companies extended
the capabilities of the methodology, until after ten years, getting the mine to produce the right
1. FAusIMM, Manager Project Development, Sustainable Minerals Institute, The University of Queensland. Email: [email protected]
Previously: Director, Julius Kruttschnitt Mineral Research Centre, University of Queensland.
First Extractive Metallurgy Operators’ Conference Brisbane, QLD, 7 - 8 November 2005 5
T J NAPIER-MUNN
ROM size was not only possible but being achieved in many operations. The quantified benefits
were often huge: 20 per cent increases in plant throughput for minimal, if any, capital expenditure
were not unusual.
Of course the truth was that some operations had been cleverly and effectively practising
Mine-to-Mill® for years. It just wasn’t called that, and, more importantly, until the sustained R&D
was done there was no systematic methodology available to capture and implement the basic idea.
Like all the best ideas, it was simple. As Figure 1 shows, the key was ore characterisation,
modelling, prediction, andimplementation.
IMPLEMENT VALIDATE
ROCKSAMPLES
YES
Comminution
CHARACTERISE NO
DESIRED
Blasting RESULT?
100 ROMSize
80 ADJUST
60 SIMULATEPLANT
40 VARIABLES
20
0
1 10 100 1000
Simulate CHARACTERISE
ROCKMASS
BLASTDESIGN
FIG1 - The Mine-to-Mill®methodology.
In recent years it has become apparent that this simple idea is capable of extension to attributes
other than fragmentation (and indeed grade, the rather limited property commonly used in mine
planning). Some mining companies have begun incorporating other attributes into their planning,
and some methodologies have been developed by others to assist in this process. Recent feasibility
studies undertaken by the JKMRC, with support from the University of Queensland’s Sustainable
Minerals Institute, have confirmed that grindability and texture are useful attributes in this regard.
Andwhilethiswasgoing on, our colleaguesatCODES(theCentreforOreDepositStudies) atthe
University of Tasmania were thinking along similar, though inevitably geological, lines. The result
has been a meeting of the minds of extraordinary fecundity and, one has to say, pleasure. And thus
has come to pass GEMIII – Geometallurgical Mapping and Mine Modeling, aka AMIRA Project
P843 – supported by 12 international mining companies and the ARC.
GEMIII is in every sense a natural evolution of Mine-to-Mill®. As did its predecessor, it exploits
careful ore characterisation and classification to achieve large process improvements and thus
increased profits. However, it is more ambitious and wide-ranging, and its potential impact on the
industry will be correspondingly large. Most importantly, it deliberately sets out to bring together
the threeminesiteprofessions – geology,mining and metallurgy – in asynergistic partnership that
exploits the skills and passions of each for mutual benefit. In particular, it proposes to join the
geologist’s skill in classification with the metallurgist’s need to know the characteristics of the
plant feedstock. This leads to the radical idea of the mineral ‘factory’in which the emphasis is on
achieving consistency and certainty – ‘no surprises’ – which any metallurgist will tell you is the
prerequisite for optimal process performance. But it can’t be done without whole-hearted
collaboration between geologists, miners and metallurgists, and a shared bag of tools.
6 Brisbane, QLD, 7 - 8 November 2005 First Extractive Metallurgy Operators’ Conference
Pilot Studies of the Ravensthorpe Nickel Project’s Pressure Acid
Leach Slurry Heater
1 2
D White and M Miller
ABSTRACT The processing route consists of mining, beneficiation, pressure
acid leaching, atmospheric leaching, neutralisation and
Operators of nickel laterite pressure acid leach and gold pressure
purification, residue washing and metals precipitation. The
oxidation technology frequently employ a series of steam condensing
general hydrometallurgical flow sheet is shown in Figure 1.
heaters to preheat the leach feed slurry. The heaters are an economic
pinchpoint–althoughthethermalperformanceoftheheatersiscritical
tooverallprocessviabilityandoperatingcostminimisation,theyarealso
a significant capital item and must be sized accordingly. Despite this, LimoniteBeneficiation SaproliteBeneficiation
discussions of the factors underlying heater design are conspicuously
absent from technical literature, and existing operations feature a
conflictingrangeofheatersizes andconfigurations.Thisvarietywould PressureAcidLeach Acid Pre-Leach
suggest that at least some of the chosen heater designs are oversized.
As partofits detaileddesignstage, the RavensthorpeNickel Project
(RNP) constructed and tested a pilot plant heater to develop an AtmosphericLeach
understandingoftheheatingprocessandtoensurethattheRNPheaters
were appropriately sized. This testwork used RNP slurry at design
density and viscosity on a 450 mm diameter, 6500 mm high column. InducedJarosite
Precipitation
The pilot plant testwork demonstrated the intrinsic efficiency of the
direct steam condensation heating process, which was essentially
Limestone PrimaryNeutralisation
independentofslurrydensityandviscosity.Presenceofnon-condensable
gases in the steam phase decreased the heat transferred in certain
circumstances, but heater performance remained consistent with
CCD's TailingsStorage
thermodynamic limitations.
Stagewise heat transfer within the column was rapid, and suggested
eitheraveryhighslurrysurfaceareaorexcellentheattransferwithinthe Secondary
Neutralisation
slurryphase.While the testworkdidnotset outto distinguishbetween
these effects, physical evidence pointed to droplet formation in the
inter-tray shower zone, giving a high heat transfer area. MgO MiPxeredcHipyidtartoioxnide Filtration&Despatch
Forscale-uppurposes,thekeyfactswerethattheheattransferratewas
notlimitedbyusinghighviscosityslurriesandheaterscouldbedesigned
using the principles applied to the smaller of those in existing operations. Lime PSreccaivpeitnagtieorn
This paper discusses existing slurry heater designs, the current
understandingfromopenliterature,thepilotplanttestwork,resultsand
analysis, and scale-up to commercial sized equipment. ManganeseRemoval TailingsStorage
INTRODUCTION
FIG1 - Simplified RNP flow sheet diagram.
Project background
Pressure acid leaching
Ravensthorpe Nickel Operations Pty Ltd (RNO) is developing
the Ravensthorpe Nickel Project in the south coast region of Pressure acid leaching (PAL) is a critical process step of the
WesternAustralia,approximately550kmsouth-eastofPerthand RavensthorpeNickelProject.Itisthemajorconsumerofsulfuric
155 km west of Esperance. RNO is 100 per cent owned by acid and high pressure process steam, and operates at the most
Queensland Nickel (QNI), a wholly-owned subsidiary of BHP extreme combination of temperature, pressure and corrosive
Billiton. conditionsontheproject.Toachievethis,theequipmentutilised
At full production, RNP will produce a nominal 50 000 tpa on the two PAL trains at Ravensthorpe is capital intensive,
nickel and 1400 tpa cobalt contained in a Mixed Hydroxide consistingofbrick-linedandtitaniumvessels,titaniumpiping,as
Precipitate (MHP) intermediate, most of which is to be shipped well as severe service valves and pumps.
to QNI’s refinery at Yabulu, near Townsville, Queensland, for Leaching iscarried outat250ºCandanoperating pressureof
finalprocessingtorefinedmarketproducts.TheYabulurefinery approximately 4500 kPag, not primarily for extraction of nickel
is to be expanded to accommodate the additional nickel inputs, and cobalt, but for impurity rejection. Iron, aluminium and
which will take the site nickel production to 76 000 tpa. chromiumleachandlargelyreprecipitate.Atlowertemperatures
The Ravensthorpe project orebody primarily consists of three these elements would stay in solution increasing acid
separate laterite deposits with measured and indicated resources consumption. Thus, the elegance of the PAL process lies in it
of275Mtat0.66percentNiatacut-offgradeof0.30percentNi. combining the three functions of leaching, impurity rejection,
and acid recovery in a single process step.
1. MAusIMM,PrincipalProcessEngineer,BHPBilliton,Ravensthorpe Theonlysignificantexothermicreactionsarethoseassociated
Nickel Project, PO Box Z5051, Perth WA 6831. with dilution of sulfuric acid in the leach. In order to reach
Email: [email protected] target reaction temperature, additional energy in the form of
steam, is added to the slurry. At the first PAL operating plant,
2. MAusIMM, Senior Process Engineer, BHP Billiton, Ravensthorpe
Nickel Project, PO Box Z5051, Perth WA 6831. at Moa Bay, most steam is added directly to the Autoclave
Email: [email protected] (Carlson and Simons, 1961). This is intrinsically energy
First Extractive Metallurgy Operators’ Conference Brisbane, QLD, 7 - 8 November 2005 9
D WHITEand M MILLER
intensive. An alternative technique, used in some gold pressure slurry feed temperature is less than its design target, the energy
autoclaves and in more recent PAL operations, is to capture the shortfallhastobemetbyadditionalhigh-pressuresteam,withan
steam released from the slurry letdown stages and contact this obviousimpactontheplantenergybalanceandoperatingcosts.
directly with cold incoming slurry ahead of the autoclave. The Failuretooperatetheautoclaveatdesigntemperaturecanaffect
vessels where this slurry-steam contact is made are known as the process by increasing the acid consumption, reducing the
leach kinetics or leach efficiency, or adversely affecting the
heatersorcondensers.AdiagramofatypicalPALtrainisshown
settling characteristics of the leach residue.
in Figure 2.
Historical context
ToGas
Scrubbing Directcontactcondensershavebeeninusesinceindustrialscale
steamengineswereinventednearly300yearsago(BCLM,2005;
HP Csele, 2004). These evolved to the high capacity barometric
Heater HP condensers in modern industrial use. Interestingly, although a
Flash
LP Vessel number of design configurations have been utilised, little
Heater information exists on heat transfer rates and even standards for
barometric condensers (HEI, 1995) have no information on
Steam
sizing for thermal performance.
Acid LPFlash
Whereheattransferrateshavebeendetermined(How,1956)it
Vessel
is by reverse engineering from operating equipment, where
nozzle placement and size appear to be the main drivers of
equipment size.
Slurry
Feed Autoclave NeutrTaolisation In the laterite nickel industry, direct contact heaters were
installed on the Tailings Stills at Nicaro, Cuba in 1944 (Boldt,
HPHeater Autoclave 1967). Beaverlodge Uranium, Canada, which commenced
FeedPump FeedPump
operations in 1954, included pressure leaching with vacuum
FIG2 - Schematic of a typical PAL autoclave train. flashing and direct contact splash heaters (Mancantelli and
Woodward, 1955). The first pressure acid leach operation, at
Moa Bay, Cuba commissioned in 1959, uses direct contact
The role of the heaters heaters with a packing ‘fabricated of expanded metal lath’ to
cope with the ‘extremely high effective viscosity’(Carlson and
Heatersarecounter-currentflowdevices,inwhichflashsteamis
Simons, 1961).
injected at the bottom of a column against a falling stream of
slurry, which is pumped into the top of the column. Heat and Gold pressure oxidation operations in North America have
masstransferoccursimultaneouslyasthesteamiscondensedby made extensive use of ‘splash heaters’utilising flash steam for
the cool slurry. preheating incoming slurry. There have been at least 16 leach
trains in six operations built since 1985, with each train
Heater designs include splash trays or disk and doughnut
containing two or three heaters (Mason and Gulyas, 1999).
arrangements to redistribute the slurry and improve the heat
transfer (Houghland, Lemieux and Schreiner, 1954; Fair, 1993). In the late 1990s, three laterite PAL plants commenced
More complex packing or bubble cap contacting methods are operation in Western Australia. These utilised the basic design
generally avoided in slurry service because of the risk of principlesdevelopedfortheNorthAmericanPressureOxidation
blockage and scaling. plants. Between two and four stages of direct contact heating
Pressure from the autoclave discharge slurry is released were installed. The authors are aware that heater sizes varied
through ceramic choke valves into a series of brick-lined flash significantlybetweentheseoperations,despitethroughputsbeing
vessels.Each flash vessel is usually associated with a particular similar. As an example, heater diameters varied by a factor of
heater andthereareusuallytwoormoreheaters inseriesahead two or more. The number of trays also varied, as did tray
of the autoclave. The temperature profile along the heater train spacing.Inoneoperationanumberoftraysfelloutwithoutloss
results in a corresponding pressure profile, and pumps are of performance. In another they were all removed and
located after each heater to direct the slurry to the next heater performanceapparentlyimproved!Furtherinvestigationrevealed
stage and finally to the autoclave vessel. thatsimilarsizedisparitiesexistbetweengoldpressureoxidation
operations.
Centrifugalpumpsareusedtopumpslurryfromoneheaterto
the next, whereas the autoclave feed pumps consist of one or During development of the Ravensthorpe Project, it was
more positive displacement pumps operating in parallel. The established that equipment size and capital cost, particularly
positive displacement pumps are fitted with water-cooled aroundtheautoclaves,couldbeminimisediftheoreslurrysolids
‘drop-legs’toseparatethesensitivepolymerdiaphragmfromthe content was maximised.
hot slurry. The drop-legs maintain an oscillating column of There was scepticism about the practicality of this in three
cooled slurry, which transmits the pumping impulse to the hot areas:
autoclave feed slurry. While the drop-legs protect the pump
1. pumping,
diaphragm from heat degradation, the pump check valves are
exposed to the full slurry temperature from the final heater. 2. slurry flow within heaters, and
Degradation of the check valves places a ceiling on the
temperatures the pump can handle, and thus on the final heater 3. heat transfer.
discharge temperature. Typically, this is in the range 160ºC to AdvicewasreceivedfromRheologicalConsultingServicesat
200ºC, and represents the autoclave slurry feed temperature. the University of Melbourne that slurries with a yield stress in
After dilution of sulfuric acid, the remainder of the heat excessof100Pacouldbepumpedwithconventionalcentrifugal
necessary to bring the slurry to 250ºC is provided by high pumps.DiscussionswithWorsleyAlumina personnelconfirmed
pressure steam injection. this, and that thickeners, particularly Deep Cone Thickeners,
A major issue to consider in the heating process is efficiency couldproducehighrheologyslurries.Therheologicalproperties
of heat transfer. If flash steam bypasses the slurry stream, this of the slurry used in the present work have been reported by
energyislosttoatmosphere.If,asaconsequence,theautoclave McCrabb, Chin and Miller (2004).
10 Brisbane, QLD, 7 - 8 November 2005 First Extractive Metallurgy Operators’ Conference