Mineral Sands Mining and Processing
Iluka Resources Ltd
3 May 2011
2
Mining in Mineral Sands
Mining method selection Depth Hardness Ground water Pit geometry Ore body geometry Sequencing Environmental effects
Objectives Minimise unit costs Sustainable mining
General Mining Sequence
Ore to out of pit mining unit
Small bund or drain to aid in
directing reclaimed tails
water
Unconsolidated tails beach
Tailings water collection point
Distance to be greater than
100m
Distance to be approximately
100m
Overburden stripping
Top soil and sub soil removed
Topsoil and Subsoil Removal
Overburden Stripping
Overburden Stripping
Overburden Stripping
Ore Mining
Ore Mining
Ore Mining
Ore Mining
Tailings Backfill
Tailings Capping
Rehabilitation
15
Depth and Hardness
• Strip ratio’s vary widely Kulwin 1:5 Jacinth-Ambrosia 1:0.4 Douglas - Varied
• Generally ‘free dig’ overburden and ore some ripping required indurated material usually laminar oversize material +2mm varies
between 2 and 20%
Groundwater
• J-A, Douglas and WA mines above the water table• Kulwin and WRP mostly below the water table• Infiltration of up to 120 l/s disposed into pit void• Hypersaline environment• 4-6 weeks dewatering dewater before mining ore
Ore Body Geometry
• Typically beach head or strand style • Strands generally shorter life• Ore body thickness – 0.5m to 18m• Strand lengths up to 14km• Strand width mineable down to 10m• Mining method to maximise recovery• Flexible fixed plant solutions required
Ore Body Geometry
Med.grained sand with irregular patches of HM
Med.grained sand with abundant fine HM laminations
Fine-med. Grained sand with numerous fine HM laminations-minor x-bedding
Coarse sand and gravels with finer med.sand interbeds
v.Fine white silty sand
35.6 – 9 - 4
35.1 – 9 - 16
3.5 – 16
8.9 – 11
4.2 – 11
0.1 – 6
1.5 – 16
Expected drill hole location
280mm
200mm0mm
v.Poorly sorted v.Coarse gravels and cobbles
Med.grained sand with irregular patches of HM
Med.grained sand with abundant fine HM laminations
Fine-med. Grained sand with numerous fine HM laminations-minor x-bedding
Coarse sand and gravels with finer med.sand interbeds
v.Fine white silty sand
35.6 – 9 - 4
35.1 – 9 - 16
3.5 – 16
8.9 – 11
4.2 – 11
0.1 – 6
1.5 – 16
Expected drill hole location
280mm
200mm0mm
v.Poorly sorted v.Coarse gravels and cobbles
Ore Body Geometry
1.3 – 14
Drill hole
v.fine silty sand
sub-horizontal
31347E
60.3 – 8v.fine silty sand
Laminated med.grained sand
Note extensive interfingering of silts and sands
1.3 – 14
Drill hole
v.fine silty sand
sub-horizontal
31347E
60.3 – 8v.fine silty sand
Laminated med.grained sand
Note extensive interfingering of silts and sands
Ore Body Geometry
Sequencing – Mine Planning
• Life of mine cycle important • Logistical exercise• Dewatering, mining, tailing, infiltration, direct return backfill• Strong focus on scheduling and grade control to ensure maximum recovery• Continuous improvement opportunities sought
Continuous Improvement Opportunities
+300mm oversize rejected from MUP
Oversize crushed to -75mm
-300mm oversize remaining after reprocessingHMC stockpile from the 5,000t processed
Various Dry Mining Process Flows (Iluka operations are primarily dry mining)
657E
Oversize
Simple Mining Unit:• Mobile• Suitable for dunal sands with low
clay and rock• Low M&H cost therefore low cut-
off grade (depending on strip ratio and assemblage)
• Low utilisation as range limited by tramming distance limitations of FEL/Dozer -> need to move at ~100m
Stationary Mining Unit• Design for high energy
beneficiation (high clay and rock) with higher work index
• Autogenous mill / drum scrubber allows for higher HM recoveries
• Higher opex, often used in conjunction with ROM ore pad, and hence double handling
• Scraper mining with/without FEL plant feed
• Truck and Shovel with/without FEL plant feed
Oversize
Concentrator Feed
Concentrator Feed
Secondary Screen
Pri. Screen
Ore Bin and. Feeder
Secondary. Screen
Tertiary. Screen
Autogenous Scrubber
24
Key Technical Considerations(for design and operation of mining units)
• Clay Characterisation mineralogy, plasticity, bulk properties and work index influence mining unit configuration
• Oversize Characterisation mineralogy, abundance and distribution contained HM and mineralogical value of HM contained
• Slurry Handling Systems liquefaction demand, pumping system duties and water recovery
• Mobility mass and maneuverability power supply, control and communications pumping system duty range
• Beneficiation recoveries need to approach 100% of HM rock charge recycling into scrubbers to maintain charge water demand, water recovery and behaviour of non-newtonian fluids
• Imperfect design has deleterious effects on margins high fixed cost burden (maintenance, power and labour) unfavourable performance outcomes drive up mining unit costs (low mobile equipment utilisation) performance critical to utilisation of downstream processes which have high fixed cost ratio’s
Quartz Tails
Typical Concentrator Process Flows
Fines Thickener
UCC
Gravity Circuit Feed
Solar Evap Dam
Magnetic Separation
Ilmenite Tails
CD Tank
Tails Dam in mine void
Pre-Concentrator (mob)From Mining
Unit
RHF Stockpile & reclaim
Concentrate
Gravity Circuit
Concentrators• Multiple configurations• Config dependent upon HM
upgrade ratio and mineralogy• Numerous tails handling and
disposal options• High utilisation and high VHM
recovery required for maintaining capital efficiency and minimisingmining costs
26
Key Technical Considerations(for design and operation of concentrators)
• Clay Characterisation – thickener design and operation abundance (ratio Clay : Sand) – hydrocyclone circuit and dilution demands process water quality (source and in-process equilibrium) dissolved salts, suspended solids, reagent interaction flocculent response, coagulant demand, consolidation profile (thickener and tails void)
• Heavy Minerals sizing in relation to gangue (quartz) – spiral duty selection and feed presentation concentrator duty (upgrade ratio) range (3% HM to 25% HM feed grade not uncommon) need for pre-concentration – consideration based on ore geography and plant mobility mineralogy - valuable and non-valuable components of HM suite (HM’s ain’t HM’s) release curves – maximum achievable VHM recovery ratios need for magnetic separation – optimising ilmenite transport and treatment cost vs value process water considerations – managing effects on HM surfaces attrition scrubbing circuits – viscosity modifiers and their interactions with flocculent
• Slurry Handling Systems complex multi-components systems often with long pumping distances (up to 10km)
• Imperfect design has deleterious effects on margins recovery (+95%) is the highest driver of NPV, low recoveries drastically effect project economics low product grade adversely effects the performance of downstream mineral separation processes management of water systems can effect downstream surface dependent processes in mineral separation
Mineral Separation Plant(typical feed preparation circuit)
Train 1 Alt. Train
HM Concentrate
Alternative Feed via Rail
Alternative Feed via Road
Salt / Clay Residues
Recovered Water
Washing Filter Belt
Trash ScreenAttrition Scrubbers
Feed Dryer
Feed Bins
Water Clarifier
Reagents
Reagents
Reactor
Paste MixerPre-heater
Rinsing & Neutralisation
Electrostatic Separation Circuit
Typical Mineral Separation and Zircon Finishing Process(options for zircon leach either upstream or downstream of final electrostatic and magnetic finishing)
Wet Gravity Circuit
Electrostatic Separation Circuit
Electrostatic Separation Circuit
Oversize waste
Ilmenite
SiO2/AlSiO5 Tails
Zircon Conc.
ZirconN/Cond
Rutile HyTi
Feed BinsAlt. Train
Ilmenite Mag Sep and Electrostatics
Secondary Ilmenite
ZrSiO4, TiO2, P2O5 Tails
Premium Zircon
Standard Zircon
Zircon Leach (opt config)
Conductors
29
Key Technical Considerations(for mineral separation plants and product specifications)
• Surface Preparation – engine room of plant is electrostatics, high dependence upon surface condition Al:Si coatings (either bound or unbound) reduce electrostatic response on all minerals hematite and goethite on zircon – less conductivity differential between zircon and rutile / leucoxene all surface contamination affects product specification limits ( hence saleability) and mineral recovery salts on surface effect atmospheric sensitivity, with managing atmospheric variation is critical process control
• Characterisation of ilmenite magnetic distribution, alteration and intrinsic elemental quality determines the suitability and specifications for sulfate feedstock, chloride feedstock and/or SR conversion highly altered species (leucoxenes) are less recoverable than less altered (primary or secondary ilmenite)
• Mineralogy and Morphology – key recovery driver abundance of non-valuable HM’s determines design duty (upgrade ratio) of each circuit and hence recovery size distribution and irregular shape affects separation efficiency and classification stages required in-process advanced SEM technology employed for characterisation primarily non-chemical processes - Intrinsic quality determines the saleability and recovery of each product
Premium or standard zircon (Al, Ti, U, Th, Fe, sizing) -> market size and pricing HyTi or Rutile specification (% TiO2) plus contaminants (Zr, Sn, Fe U+Th) determines market options intrinsic contaminants in ilmenite effect market options (chloride, sulfate or SR conversion)
Waste Gas System
Typical Synthetic Rutile (Becher) Process(waste gas systems can include power generation turbine)
Ilmenite Coal
AerationAeration
NH4Cl
Reduction Kiln Rotary Cooler
Screening
Mag Separation
Char recycle
Reduced Ilmenite
(TiO2.Fe)
Filtration
Drying
Dust Recovery
Hx
Scrubbers A/Burner
Synthetic Rutile
Oxide Dams
CaSO4.2H2OWaste Dams
CaSO4.2H2OWaste Dams
Neutralisation
Recovered NH4Cl
Natural Gas
Ca(OH)2
Fe3O4
SR
SR
SRAcid Leach
31
Key Technical Considerations(for Ilmenite Upgrading via Becher Process)
• Ilmenite Quality TiO2 grade -> drives unit cost of production Fe grade -> iron is the key to the process throughput and hence major unit cost driver (coal and reagents) Al and Si -> affect the degree of sintering, intrinsic contaminants dilute product TiO2
Mn and Mg -> manganese and magnesium determines maximum Fe removal U + Th -> governs marketability -> higher U+Th increases activity of pigment plant waste alteration of ilmenite-> more altered ilmenites are more reducible often chloride ilmenites can be suitable SR feed stock few ilmenite deposits make suitable SR feed stock, ilmenite quality requirements are fundamental to viability sizing affects the suitability of SR for some chlorinators, although advantageous for some to have finer feeds
• Product Specification –> Step change in cost profile often occurs between Standard : Premium : SREP higher TiO2 product increases reagent consumption higher TiO2 limits throughput – more Fe and Mn removal required threshold targets on TiO2 drive technology employed and reagent suite:
Standard grade – leaching ends following aeration, little to no sulfuric acid, neutralisation and dam costs Premium Grade – requires Sulfur addition and high acid demand -> with waste dams and neutralisation SREP – requires flux addition to kiln, high acid demand plus caustic soda
trace contaminants – limit ilmenite suitability and also govern technology employed
Ore Grade Impact on Pigment Processes
TiO2 Pigment Production Process
Chloride Process (55% of Capacity)
Sulphate Process (45% of Capacity)
Ti Feedstock Chlorination
Cl2 +Coke
Distillation
Waste
TiCl4 Oxygenation Finishing
Ti Metal
UniqueMarket~ 10%
Ti Feedstock Acid Digestion
H2SO4
Purification
Waste
TiOHh Calcination FinishingUniqueMarket~ 10%
CommonMarket~ 80%
Sulfate Ilmenite• Chinese• Moma
• Kwale (?)
Titanium Feedstock Market Segmentation
34
Titanium Feedstock (TiO2 grade)
Sulfate Slag• QIT Sorel Slag
• Chinese
Chloride Ilmenite• Iluka• Moma• Ukraine• New Players(?)
Leucoxene and HyTi• Iluka• Bemax• Doral• New Players(?)
Chloride Slag• RBM• Namakwa SR Std & Prem
• Iluka• TiWest
UGS• QIT
91% Slag• QMM Rutile/HyTi
• Iluka• SRL
SREP• Iluka
95%85% 90%80%70%60%55%
TiO2Grade
High Grade Chloride
Chloride SlagChloride Ilmenite *
Sulfate Ilmenite Sulfate Slag
Note: Producer examples only (not necessarily exhaustive).* Leucoxene is included with ilmenite as these generally feed the same pigment plants and is a very small part of the chloride market.
Sulfa
teFe
edst
ocks
Chl
orid
eFe
edst
ocks
Chloride Pigment
36
Benefits of High Grade Feed
• Increased pigment production chlorinators are usually Cl2 constrained thus maximum production is achieved by converting as much
of the Cl2 in the chlorinator feed as possible to TiCl4 which means a high grade feedstock favoursmaximum production
• Lower Production costs chlorine consumed by the non TiO2 “others” in the feedstock is lost therefore the utilisation of chlorine
on lower grade feeds is lower (= higher cost) than for a higher grade feed neutralisation reagents cost is lower as there is less non-TiO2 waste to neutralise
• Operability higher grade feed generally makes the chlorinator easier to operate as there is less of the
problematic trace elements (e.g. Ca, Mn and Mg) that cause chlorinator operation difficulties (stickiness in the bed and scaling of ducts from higher BP chlorides)
• Reduced amounts of waste to neutralise and send to land fill higher grade ores have low quantities of non TiO2 elements that have to be neutralised and then
carted / stored / disposed
Traditional Feeds
• Chloride ilmenite TiO2 58-62% only DuPont uses this feedstock:
they have deep welling waste disposal which is cheap have Fe(III) Chloride sales revenue from waste (i.e. Edge Moor)
high chlorine consumption which relies on cheap chlorine which is often available in North America (related to the production of caustic for plastics production)
if running on Cl2 limit, constrains pigment production
• Chloride Slag TiO2 85-86% (QMM ≈ 91% TiO2) more Cl2 consumption per TiO2 unit than rutile due to higher trace elements lower energy demand from rutile being reduced if feed unscreened (as in China) then higher chlorinator carry-over losses than rutile
• SR TiO2 85-93% more reactive than rutile and slag due to the porosity porous therefore more reactive -> higher throughput narrow size range makes it very easy to operate chlorinators
• UGS TiO2 95% very clean (it is slag product that is roasted and leached to remove Ca and Mg from sulphate slag) limited supply and expensive to make compared with lower grade chloride slag
• Rutile TiO2 95% industry standard preference -> only 1.15 – 1.20 t per tonne of pigment (least constraints and least waste) limited supply
37
Sulphate Pigment
39
Benefits of High Grade Feed
• Increased pigment production no significant difference as higher grade is offset by slower digestion / baking times
• Lower production costs reduced acid consumption as no acid lost to a copperas product scrap Fe is not required as there is no Fe3+ present in the ore (slag) – partly offset by
the cost of oxidants (O2 or NaNO3) for converting Ti3+ to Ti4+
the cost of neutralising chemicals is lower as there is less to neutralise
• Operability no real differences
• Reduced amounts of waste to neutralise and send to land fill higher grade ores have low quantities of non TiO2 elements that have to be
neutralised and disposed of particularly if there is no market for copperas
Traditional Feeds
• Ilmenite TiO2 48-56% high Fe contents consume acid and generate large volumes of waste – can be offset by sales of copperas (FeSO4) presence of Fe3+ requires the addition of scrap Fe to reduce to Fe2+ otherwise pigment is discoloured. Also requires
plant for the copperas precipitation
• Sulphate Slag TiO2 78-84% low Fe means a reduced waste volumes no Fe3+ therefore no reduction stage (no scrap Fe needed) must contain MgO to provide acid soluble TiO2 phases and can be converted into a saleable by-product requires higher acid concentration for digestion which reduces the ability to recycle waste acid from the process which
leads to higher consumption of concentrated (often purchased) acid doesn’t require a copperas precipitation step
• Acid Soluble SR TiO2 85-90% TiO2 low Fe means a reduced waste stream no Fe3+ therefore no scrap reduction stage porous and finer particle size means less grinding required for digestion (power and grinding media savings)
40
Feedstock Interchangeability
• Sulfate Plants lower TiO2 ilmenites reduce TiO2 pigment production, prefer +54% TiO2
most plants can treat Sulfate Slag – no by-product credits not all plants can treat ilmenite
• Chloride Plants ilmenite suitable for DuPont USA plants only most operate on a blend of feeds to get +85% TiO2 feed grade those accustomed to high grade feeds (SR and Chloride Slag) become constrained
with lower TiO2 feed natural rutile substitution for SR/UGS/Chloride slag cause reaction rate constraints many have relied on Iluka (⅔ global SR supply) for grade boost with Iluka reducing high grade TiO2 output (⅔ global SR) by almost half and key
competitors being production constrained, demand for high grade TiO2 is strong. modification and/or expansion to maintain capacity with lower grade feeds is expensive with low surety of supply and capital intensive expansion options, high TiO2 feedstock
is needed to maintain or boost output
41
Closing Statement
Closing SlideIluka Resources Limited
For further information, contact:Robert PorterGeneral Manager, Investor Relations
[email protected]+61 3 9600 0807 / +61 (0) 407 391 829www.iluka.com