KAOLIN NOT JUST FOR INDIGESTION Sue Border COMMERCIAL
KAOLIN NOT JUST FOR INDIGESTION…. Sue Border
COMMERCIAL KAOLIN • • White (white firing) non-swelling clay Also called “China Clay” Dominantly kaolinite q. World Production q. Export markets 30 mtpa (US$3 b) 9 mtpa
USES OF KAOLIN v v Papermaking Pigment/Filler/Coating Pigment in paint/inks High Plastics/Rubber Value Ceramics o Mineral Filler o Source of Al 2 O 3 o Refractories Low Value Products
Commercial Economics PREMIUM GRADE CRITERIA A high priced Kaolin has : v v v v Superior Brightness Superior Whiteness Desired particle size High opacity (good hiding power) Chemical purity Low viscosity (for paper markets) Other properties - abrasivity, conductivity, etc
Pigment markets Brightness Competitors Pigment v Ti. O 2 v Ca. CO 3 v Kaolin Price per tonne (A$) $3500 - $6000 $350 - $500 $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: Georgia Brazil UK * Source: Pulp and Paper Magazine
CHINA KOREA JAPAN TAIWAN CANADA THAILAND West Coast USA MALAYSIA INDONESIA EUROPE AND MIDDLE EAST PROJECT AUSTRALIA LOCATION TASMANIA NEW ZEALAND
KAOLIN FORMATION v Economic deposits mainly weathering related v Associated with laterite and bauxite v Formed in wet/dry tropical climate v Over 1500 m rain pa v Leaching process
LATERITIC WEATHERING BAUXITE --- Highest water IRONSTONE Leaching MOTTLED --- Lowest water of cations PALLID BEDROCK
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 v Ferrous leached more easily than ferric. Least iron just below lowest water table But leaching is slow below the water table Organic grey kaolins formed here.
DIAGENESIS OF KAOLIN q. Feldspars & clays kaolinite q. Kaolinite increases in grain size ü 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…. v. Andrew White in 1985 • 19 holes • 2 in lease • Target of “Bulimba” kaolin found; • Older weathering kaolin noted. • Samples to CSIRO
SKARDON RIVER KAOLIN exploration history pre SRK v v v 1986 - Drilled 93 holes - geology only 1987 - 1990 Bulk sampling & testwork 1993 - 188 RC holes - geology & ‘clay’ 1994 - 10 DD holes 1994 - 97 - Testing selected drill samples 1997 - 207 RC holes - poor control
MISTAKES…. . o No initial raw values o Did not relate metallurgy to geology o Poor technical knowledge at board level o Moving goal posts o Rolls Royce plant o Major cost over-runs o No coordination of consultants/contractors
GEOLOGICAL HISTORY…. . Cretaceous - Marine Shale
Uplift and Weathering. . . Claystone Rolling Downs Formation
Tertiary Sheet Fluvials Bulimba Formation
Weathering to bauxite
Fluvial Channel Develops Namaleta Creek Floodplain
Further Weathering…. . . K 3 Fluvial Claystone
Claystone Mining
Conchoidal claystone
Fluvial in exploration pit
Wet Plant DRILLHOLES AND OUTLINE OF FLUVIAL CHANNEL ML and Drilling Green – RC holes Black – AKL grade control holes
RESOURCES Purple – inferred claystone Grey – measured claystone Blue – inferred fluvial
Resource Summary In 000 s t Claystone Measured 640 Meas + Ind claystone Fluvial Indicated 920 Inferred 5, 200 1560 728 Total 100 years at 75, 000 tpa. 4, 270
Skardon Kaolin Properties Grit content (+ 45 m) -45 m psd Claystone K 3 Fluvial 3% 56% 55% 70% -1 m 75% -1 m 80% -1 m Brightness, 65 60 -5 m (ISO %) Hydrous prod’t 70 70 (ISO%) Calcined bright 90 – 91. 5 83 -ness (ISO %) 70 +85 91
Skardon Product Range • Hydrous Kaolins • Calcined Kaolins Plant capacity 75, 000 tpa • Wide range of industrial • Higher performance • Better brightness, • • applications Represents the bulk of world supply Target of paint & rubber markets • • opacity Competes with Ti. O 2 Premium price Limited number of producers Paint, rubber, paper
Stage 1 Processing: Wet Plant Kaolin Ore Blunger Degritting Centrifuge Sand Decanter Centrifuge Delaminating Mill, Leaching circuit Disc-nozzle Centrifuge Tailings Dam High Gradient Magnet Separator Membrane Filter Pipeline to Dry Plant
Stage 2 Processing: Dry Plant Pipeline from Wet Plant Pulveriser Calcining Kiln Pulveriser CALCINED KAOLIN Spray Dryer HYDROUS KAOLIN
MAJOR WORLD DEPOSITS Ø Georgia, USA Ø Amazon, Brazil Ø Cornwall, UK ………. the odd one out q. Hercynian granite 280 m. A q. Debate weathering vs hydrothermal q. Coarse grained well crystallised kaolin q. Very limited available resources q. Product yield 15 -20%
Georgia - Geology v. Cretaceous and Tertiary bedded kaolins v. Exposed just south of Fall Line v. Cap bentonite v. Cretaceous 60% -2 micron v. Tertiary 85% -2 micron
Georgia - Economics ADVANTAGES v Two types of kaolin v Expertise v Reputation v Transport for E USA & Europe DISADVANTAGES v Older updated plants v Mine locations v High stripping ratios v Transport to Asia
Amazon Geology Ø Under bauxite exposed on slopes. Ø Rio Jari – Pliocene, very fine grained 75% -2 micron. 36 m thick deposit. Ø Rio Capim – also Tertiary. Coarser than Jari. Thinner and some grit.
Amazon Economics ADVANTAGES ü Fine Kaolin ü Modern plant DISADVANTAGES v Pipeline distance v Transport to Asia
Summary of the Skardon River Kaolin Project v Long mine life v Growing international demand v Premium products v Exceedingly low CAPEX entry price v Best logistics for Asia v Marketing and distribution agreements v Technical Management Expertise
That’s it folks!
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