KAOLIN NOT JUST FOR INDIGESTION…. Sue Border
COMMERCIAL KAOLIN White (white firing) non-swelling clay - Also called “China Clay” White (white firing) non-swelling clay - Also called “China Clay” Dominantly kaolinite Dominantly kaolinite World Production 30mtpa (US$3b) Export markets 9mtpa
USES OF KAOLIN v Papermaking Pigment/Filler/Coating v Pigment in paint/inks High v Plastics/Rubber Value v Ceramics oMineral FillerLow Value Products oSource of Al2O3 oRefractories
Commercial Economics PREMIUM GRADE CRITERIA A high priced Kaolin has : v Superior Brightness v Superior Whiteness v Desired particle size v High opacity (good hiding power) v Chemical purity v Low viscosity (for paper markets) v Other properties - abrasivity, conductivity, etc
Pigment markets - Brightness Competitors Pigment Price per tonne (A$) v TiO2$ $6000 v CaCO3 $350 - $500 v Kaolin $200 - $1200 Kaolin gives good performance for the price
Markets - Paper Demand v Paper demand increases with GDP v Asian paper production to overtake USA by 2010* Asia imports Kaolin from: GeorgiaBrazilUK * Source: Pulp and Paper Magazine
TASMANIA NEW ZEALAND USA EUROPE AND MIDDLE EAST INDONESIA THAILAND MALAYSIA AUSTRALIA JAPAN KOREA TAIWAN PROJECTLOCATION C ANADA West Coast CHINA
KAOLIN FORMATION v Economic deposits mainly weathering related v Associated with laterite and bauxite v Formed in wet/dry tropical climate v Over 1500m rain pa v Leaching process
LATERITIC WEATHERING BAUXITE IRONSTONE MOTTLED PALLID BEDROCK Leaching of cations --- Highest water --- Lowest water
MORE EFFECTIVE LEACHING v More water flow (fresh water & permeability) v More time v More bugs v Acid groundwater (oxidising organics) § Parent is only important if time is short or leaching is slow.
REMOVAL OF IRON v Ferrous leached more easily than ferric. v Least iron just below lowest water table v But leaching is slow below the water table v Organic grey kaolins formed here.
DIAGENESIS OF KAOLIN Feldspars & clays kaolinite Kaolinite increases in grain size The perfect kaolin recipe - Formed below water table then raised above it
SEDIMENTARY KAOLINS? v Cannot separate kaolinite from other clays by sedimentation. v All commercial kaolins are formed in situ (Pickering & Hurst 1997) v Ball clays? (70% disordered kaolin).
SKARDON RIVER KAOLIN - discovery…. Andrew White in holes 2 in lease Target of “Bulimba” kaolin found; Older weathering kaolin noted. Samples to CSIRO
SKARDON RIVER KAOLIN - exploration history pre SRK v Drilled 93 holes - geology only v Bulk sampling & testwork v RC holes - geology & ‘clay’ v DD holes v Testing selected drill samples v RC holes - poor control
MISTAKES….. oNo initial raw values oDid not relate metallurgy to geology oPoor technical knowledge at board level oMoving goal posts oRolls Royce plant oMajor cost over-runs oNo coordination of consultants/contractors
GEOLOGICAL HISTORY….. Cretaceous - Marine Shale
Uplift and Weathering... Rolling Downs Formation Claystone
Tertiary Sheet Fluvials Bulimba Formation
Weathering to bauxite
Fluvial Channel Develops Namaleta Creek Floodplain
Further Weathering…... Fluvial K3 Claystone
Claystone Mining
Conchoidal claystone
Fluvial in exploration pit
ML and Drilling Wet Plant DRILLHOLES AND OUTLINE OF FLUVIAL CHANNEL Green – RC holes Black – AKL grade control holes
RESOURCES Purple – inferred claystone Grey – measured claystone Blue – inferred fluvial
Resource Summary In 000s tMeasuredIndicatedInferred Claystone ,200 Meas + Indclaystone1560 Fluvial7284,270 Total 100 years at 75,000tpa.
Skardon Kaolin Properties ClaystoneK3Fluvial Grit content (+ 45 ) 3%56%55% -45 psd70% -1 75% -1 80% -1 Brightness, -5 ISO Hydrous prod’t ISO Calcined bright -ness ISO 90 –
Hydrous KaolinsHydrous Kaolins Plant capacity 75,000 tpa Wide range of industrial applications Represents the bulk of world supply Target of paint & rubber markets Skardon Product Range Calcined Kaolins Calcined Kaolins Plant capacity 75,000 tpa Higher performance Better brightness, opacity Competes with TiO2 Premium price Limited number of producers Paint, rubber, paper
Stage 1 Processing: Wet Plant Kaolin Ore Blunger Degritting Centrifuge Decanter Centrifuge Disc-nozzle Centrifuge High Gradient Magnet Separator Membrane Filter Pipeline to Dry Plant Sand Tailings Dam Delaminating Mill, Leaching circuit
Stage 2 Processing: Dry Plant Pipeline from Wet Plant Spray Dryer Pulveriser Calcining Kiln Pulveriser CALCINEDKAOLIN HYDROUSKAOLIN
MAJOR WORLD DEPOSITS Georgia, USA Amazon, Brazil Cornwall, UK ………. the odd one out Hercynian granite 280mA Debate weathering vs hydrothermal Coarse grained well crystallised kaolin Very limited available resources Product yield 15-20%
Georgia - Geology Cretaceous and Tertiary bedded kaolins Exposed just south of Fall Line Cap bentonite Cretaceous 60% -2micron Tertiary 85% -2micron
Georgia - Economics ADVANTAGES v Two types of kaolin v Expertise v Reputation v Transport for E USA & Europe DISADVANTAGES vOlder updated plants vMine locations vHigh stripping ratios vTransport to Asia
Amazon Geology Under bauxite exposed on slopes. Rio Jari – Pliocene, very fine grained 75% -2 micron. 36m thick deposit. Rio Capim – also Tertiary. Coarser than Jari. Thinner and some grit.
Amazon Economics ADVANTAGES Fine Kaolin Modern plant DISADVANTAGES vPipeline distance vTransport to Asia
Summary of the Skardon River Kaolin Project Long mine life Growing international demand Premium products Exceedingly low CAPEX entry price Best logistics for Asia Marketing and distribution agreements Technical Management Expertise
That’s it folks!