High-Grade Iron Ore Grade Iron Ore

5/15/2009
High--Grade Iron Ore
High
Characteristics
and
Genetic Models
Important Deposits in the World
Continent
Region
Damara Belt, Namíbia
Africa
Transvaal-Griquatown, SA
Liberian Shield, Liberia-Sierra Leona
Oceania
Middleback Range, Austrália
Hammersley
Altai, W-Sibéria
Eurasia
Krivoy Rog
Bihar – Orissa, India
Grupo Rapitan – NW-Canada
North America
Lake Superior
Labrador, Canada
Isua, Grönland
Urucum/ Mutum, Brasil – Bolivia
South America
QF, Minas Gerais, Brazil
Carajás, Pará – Brasil
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High--Grade Iron Ore
High
Fetotal > 64%
SiO 2 3-4%
Al2O3 < 1%
K2O + Na2O < 0.1%
P < 0.05%
S < 0.1%
Mineralogy
•Magnetite/Martite/Magemite
•Hematite/Specularite
•Goethite
and
other
Fehydroxides
High--Grade Iron Ore
High
Banded Ore
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High--Grade Iron Ore
High
Brecciated Ore
High--Grade Iron Ore
High
Brecciated Ore
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High--Grade Iron Ore
High
Schistose Ore
High--Grade Iron Ore
High
Related Processes
Carbonate
alteration
Oxidation
Metassomatism
Laterization
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Carbonate Alteration in Fault Zone
Carajas
N4E
Carbonate
alteration
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N4E
Carbonate
alteration
HD
Cb
Cb
750 µm
Carbonate
alteration
Hm
Cb
Mt
Sample N4E/F603/P38,6
750 µm
Cb400 µm
750 µm
Carajas
N4E
H
m
Cb
Mt
400 µm
400 µm
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Carajas
N4E
Carbonate
alteration
Minérios de Ferro de Alto Teor
Quartz and Carbonate Leaching
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22. 5
20
17. 5
Al2O3
15
12. 5
10
7.5
BIF
5
ma gnetite -ca rbonate
(e nri ched BIF)
high-P hematite mineralisation
2.5
high-P ma gnetite m inera lis ation
Ratio of
immobile
elements
remains
constant
throughout the
entire
enrichment
process
low-P hem atite ore
0
0
.2
.4
.6
.8
1
1.2
TiO2
High-grade ore
from dolomitic
itabirite
Oxidation
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The Anoxic Oxidation
Crystalline Structure of Magnetite and
Hematite
The Anoxic Oxidation
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Anoxic Oxidation and Hydration
Carbonates
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Mt. Tom Price
Reservas = 200 Mt (2001)
Strip ratio = 0.9:1
Structural Control
of Deposits
Brittle Environment
4 West Basal Fault
4 East Basal Fault
MMG
BRQ
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A
FAULT
D
55
65
50
0
50
4 West
60
23 East
40
2 3 EAST
4 East
C
30
G
Upper
Lower
Hamersley
Group
Fortescue
Group
30
Eastern
Ranges
T
UL
FA
Wyloo
Group
HO
LE
30
35
Legend
5 km
35
IES
W
HO
T
UL
FA
45
BAS
AL
65
ST
EA
18
11 West
MT McGRATH FORMATION
McGrath unconformity
BEASLEY RIVER FORMATION
BQ unconformity
WOONGARRA RHYOLITE
WEELI WOLLI FORMATION
BROCKMAN IRON FORMATION
Joffre Member
Whaleback Shale Member
Dales Gorge Member
WITTENOOM, MT SYLVIA,
MCRAE FORMATIONS
CH
AN
NA
R
25
25
64 East
15
6
EA
ST
Channar
FA
UL
T
Steep Reverse Fault
B
Steep Normal Fault
Range Parallel Fault
Oblique Fault
MARRA MAMBA FORMATION
JEERINAH FORMATION
Hematite Conglomerate
BIF AND INTRUSIVE ROCKS
extension
dolomite below BIF
separated by shale
BIF
SHALE
HEMATITE CONGLOMERATE
CARBONATE
IRON ORE
VOLCANIC ROCKS
HEMATITE/ MAGNETITECARBONATE PROTORE
uplift and erosion
supergene upgrade of protores to high-grade ores
Brockman I.F. hematite
deposits
thrusting and folding
dolomite above BIF
deep supergene circulation in thrusts
and folds
Marra Mamba hematite-goethite deposits
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N4E
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Structural Control
of Deposits
Ductile Environment
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A Word about the Syngenetic Models
(Chamberlin 1883, King 1974, Lascelles
2006)
GENESIS OF BIF
A: Deposition of proto-iron formation as nontroniteFe-hydroxide turbiditic mud
Fe-hydroxide
Nontronite
B: Breakdown of nontronite to Fe-oxide and
colloidal silica
C: Settling of Fe-oxide
Fe-oxide
Silica
NONTRONITE: Ca.5(Si7A l.8F e.2) ( F e3.5 A.4l M g.1 ) O20 (OH)4
Source: Lascelles 2006
Earthquake!!!
D: De-watering and escape of silica leads to
localized formation of chert-free BIF
H2O
H2 O + SiO 2
Cherty BIF
Chert-free BIF
H2O
Cherty BIF
E: Erosion exposes chert-free BIF,
supergene processes form weathered cherty BIF and
hematite or hematite-goethite ore
Cherty BIF (weathered)
Hematite-goethite
ore
Source: Lascelles 2006
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5/15/2009
Evidences?
Chert Cover?
4cm
Fe-Oxide
“Vein”
Previsions and Evidences (?)
Primary bodies below the weathering zone
(mt/hem-carbonate-silicates )
No surface evidence of high-grade orebodies
No relation to tectonic structures
SiO2/Chert cover
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5/15/2009
Supergene Ore
Bown Ores
Structure
Weathering surface
Meteoric waters (per descensum).
Residual concentration or substitution
Structural control (great depths)
Prä-metamorphic (hard ores)
•Friable “soft” ore down to great depths.
•Related to Hard orebodies
•Related to weathering surfaces
•Commonly related to carbonatic bodies
•Oxidized/hydrated mineralogy
•Substitution of SiO2 by goethite
Supergene Ores
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Supergene Ores
20mm
GMF (Marandoo)
(Goethita - Martita)
Paraburdoo H2F (Paraburdoo)
Group B (Microplaty hematite dominant)
Hematita lamelar – Goethita
20mm
GOL (Nammuldi)
Namuldi
Group D (Goethite)
(Goethite)
20mm
Brockman HGF (Brockman No.2 Pit 4)
Group C (Hematite - goethite)
Hematita - Goethita
Paraburdoo Western Ranges
Wyloo
unconformity
BIF com forte mergulho
BIF em profundidade
Hematita microlamelar
Zonas de permeabilidade elevada
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Sishen Deposit
Example of a Paleokarst
SISHEN MIDDLE MINE
E
W
Legend
KALAHARI GROUP
POSTMASBURG GROUP
Volcanic rocks
Thrust
OLIFANTSHOEK S.GROUP
Quartzite
Flagstone
GHAAP GROUP
200m
Shale
Iron Formation
Hematite conglomerate
Chert breccia
Dolerite dike
Dolomite
Hematite ore
Unconformity
Source: Kumba
Sishen Deposit
Ore
BIF
Manganese
marker
Dolomite
0
2 km
Source: Kumba
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Hypogene Ore
Bedding -controlled
Tectonic control
Blue Ore
Soft Ore
•Banded
•Schistose
•Granular (Blue Dust)
Hard Ore
•Banded
•Massiv
•Schistose
Hydrothermal fluids (per ascensum) of different origins.
i. Leaching of SiO2 and Carbonates
ii. Fe-remobilization and concentration possible metassomatic
substitution of gangue minerals.
HM
Jp
HM
Discordant bodies
Pseudomorphosis.
Reproduction of BIF-structures
Precipitation of Fe-minerals in vugs
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Hypogene
Ore
Hipogênicos
X-tmas Tree
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High--Grade Iron Ore Veins
High
JP
HM
HD
Hypogene/Supergene
Hypogene
/Supergene Ores
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Hypogene/Supergene
Hypogene
/Supergene Ores
• Urucum
• Mt Tom Price
• Sandur SB
• Maremane Dome
• Thabazimbi
• Carajas
+ Nauga East (magmatic hydrothermal)
Geohemistry of Fe ore
Hypogene/Supergene
Hypogene
/Supergene
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Supergene Deposits - Enrichment of LREE
Enrichment of LREE is observed for all supergene high-grade iron ore types
Mobilization of HREE in weathering profiles, and concentration of LREE in the residue,
has been documented for modern environments (Nelson et al., 2003; Braun et al.,
1990).
The effect is related to the preferential complexation and mobilization of HREE in low
temperature environments
REE vs. av. Lake
Superior BIF
Empovreshment
in Y e Yb
REE Hydrotermal Hypogene Deposits
Hydrothermal deposits show either no or only moderate enrichment that is
uniform for all REE). (suggest simple residual enrichment)
A net introduction of REE may be envisaged in this example, possibly by
high salinity hydrothermal fluids HREE would have been transported more
effectively than LREE (Humphris, 1984).
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5/15/2009
REE vs. host BIF
Hydrotermal Hypogene Deposits
à Nauga East and Thabazimbi – consistente
à SSB – enriquecimento uniform -Sm and Tm artefatos
à Carajas – enriquecimento moderado em HREE, Y anômalo
REE from some Carajás oresasmples
100
100
enrichment of LREE & HREEE
Amostra/Condrito
10
1
.1
La
Pr
Ce
Nd
Amostra/Condrito
Amostra/Condrito
ETRL enrichment
Eu Tb Ho Tm Lu
Sm Gd Dy Er
Yb
10
1
.1
La
Pr
Ce
Eu
Nd
Sm
Tb
Gd
Ho
Dy
Er
Tm Lu
Yb
N5E ( 2 amostras )
N5E
N5E (1 amostra, ? do padrão geral)
Condrite normalized
Blue squares av. archean Isua
BIF, Groenland
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Amostra/Condrito
100
N4W
N5E
Jps
Jps
N5E ( 2 samples )
10
N5E
N1
1 mafic rock N4E & 1 ore N1
1
N5E (1 anomaous sample)
N4E (no Cb)
.1
N4E (with Cb) ( 2 samples )
La
Pr
Ce
Eu
Nd
Sm
Tb
Gd
Ho
Dy
Tm Lu
Er Yb
Minérios
Amostra/Condrito
100
(B)
(B)
10
1
.1
La
Pr
Ce
Eu
Nd
Sm
Tb
Gd
Ho
Dy
Tm
Er
Lu
Yb
Australian Hypogene Model
Taylor et al. (2001)
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5/15/2009
Australian Hypogene Model
Hypogene Stage
Taylor et al. (2001)
Normal fault
Magnetite-carbonateapatite protore
•
•
Removal of SiO2
Mg/ Fe alteration in
the diabase and
shales
BIF
Dolomite
Hydrothermal (alkaline) fluids
high salinity
P xT Hot (110-250oC), highly saline ascending fluids
Deep Circulation of Meteoric Waters
Microplaty hematite +/Hydrothermal (oxidized) fluids
ankerite/dolomite
low salinity
Oxidation of magnetite in martite
Hematite (carbonate)P remains
apatite protore
Magnetite-carbonateapatite protore
BIF
Dolomite
Dolomite dissolution
PxT
Hot, low-saline fluids (150-450o C),
Per descensum? (Taylor et al. 2001)
Paraburdoo: 120-150o C (Thorne 2007)
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Weathering
low-- temp meteoric fluids
low
meteoric fluids
Hematite ore
Depth of weathering
Hematite (carbonate)
apatite protore
Magnetite (carbonate)
apatite protore
Removal of apatite
Removal of remaining CaO
and MgO from the shales
Map Area
WESTERN
AUSTRALIA
0
400
800
Metres
Fault
Dolerite Dyke
Colluvium
Canga
Hematite-goethite
Hematite
BROCKMAN IRON FORMATION
Joffre Member
Whaleback Shale Member
Dales Gorge Member
MT MCRAE SHALE
MT SYLVIA FORMATION
WITTENOOM FORMATION
MARRA MAMBA FORMATION
FORTESCUE GROUP
Mount Wall Deposit
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5/15/2009
Mount Wall Deposit
B
A
DDHWLT08
DDHWLT01
ek
Cre
ault
rn F
rthe
No
da
lgee lt
Boo Fau
Depth of Weathering
DDHWLT02
DDHWLT07
DDHWLT05 proj.
DDHWLT09
proj.
Fault
Dolerite Dyke
0
100
200
Metres
Hematite/ magnetite-carbonate
Hematite (goethite)
BROCKMAN IRON FORMATION
Joffre Member
Whaleback Shale Member
Dales Gorge Member
MT MCRAE SHALE
MT SYLVIA FORMATION
WITTENOOM FORMATION
MARRA MAMBA FORMATION
FORTESCUE GROUP
Carbonate Alteration in Fault Zone
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5/15/2009
G
Microplaty Hematite
/goethite
mpH
P
0.1 mm
Mt
Mt/H
0.1 mm
H
Magnetite/martite-hematite
C
0.1 mm
Magnetite/ hematite-carbonates
Distribution of major BIF-hosted iron ore deposits
When applying a 55 wt
% Fe cut-off grade the
Indian iron ore resources
have been reported to
be ca. 25.24 billion tons
with 14.63 billion tons of
hematite-rich ore and
10.61 billion tons of
magnetite-rich ore
(Sharma, 2007).
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5/15/2009
Hard Ore
BIF
DAITARI IRON ORE DEPOSIT, SOUTHERN IOG
Goa ore
Hard ore: magnetite
40µm
Soft ore: magnetite-hematite
20µm
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ARI DONGRI DEPOSIT
MAGNETITE ORE
SPECULARITE ORE IN
SHEAR ZONES
1 5 0µ m
150µM
Ore Hauling
in India
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5/15/2009
Location of
Simandou
Range
West-African
WestCraton
Kenema-Man
KenemaDomain
(Modified after Rocci et al., 1991)
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5/15/2009
Ore Types
Powder
Biscuit
Medium-Hard
Hard
Hematite Types
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Hematite Types
Hematite
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Krivoy Rog
Geological Map
39
5/15/2009
KRYVYJ RIG Crossections
UKRAÏNE
(I.Paranko, B. Maluk)
?2?-8
9832 20500
9813
À
22350
19829
0
16987
17752 17820
20811
1242
B
Grupo Gleevatska
Quartzito, conglomerado, filito.
3292
Grupo Gdancivska
339,0
Metarenito, muscovita-quartzo-biotita xisto ,
quartzo-sericita xisto,dolomito,marmore,
formação ferrífera
750,0
1
1018,0
1238,0
1209,0
Grupo Saksaganska
2
3
Granada-cummin gtonita-clorita xisto,
quartzo-biotita xisto,quartzo-clorita xisto,
Formação ferrífera bandada (FFBs)
8044,0
3550,0
Grupo Skelevatska
4
Metaconglomerado, metarenito, meta-arcósio,
biotita-quartzo-sericita xisto,quartzo-sericita xisto, filito,
s
carbonato-talco xisto,clorita-talco-anfibólio - xistos.
5
Grupo Novokrivorizka
9432,0
Metaconglomerado, metarenito, quartzo-biotita xisto,
quartzo-sericita-clorita xisto,filito.
6
“Série” Konska
7
Anfibolito,Formação ferrífera bandada (FFBs),
t a l c o - c a r b o n a t o - a n f i b o l i o x i s to .
À
Rochas graníticas
(Complexo de Saksaganskiy)
Cavalgamento
Falha
B
1256.3
Furo de sondagem
Rochas graníticas e migmatíticas
(Complexo de Inguletskiy)
Nort
e
Saksagan
Mineral SubSubdistricts from
Kryvyj Rig
Tarapako-- Lihmann
Tarapako
Krivoy Rog
Central
Inguletz
(Lihman)
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5/15/2009
KRYVYJ RIG Ore
Deposits
Gannivske
Pervomayske
mina V. Lenin
mina Gvardiyska
mina Juvileyna
mina M. Frunze
High-grade Ore Deposits
Gleevatske
mina Bilshovyk
8-10 million tons/ano
mina Oktyabrska
mina Rodina
mina S. Kirova
mina Gigant-Glyboka
Low-Grade Ore Deposits
Novokryvorizke
Valyavkinske
Skelevatske-Magnetitove
80-100 million tons/ano
Jazida de baixo teor
Jazida de alto teor
Inguletsky
Krivoy Rog Ore and BIFs
Magnetite and silicatesilicate- carbonate
carbonate-- magnetitic ores
Na-Metassomatism
Martite and Martíte - hematite ore
Soft and hydrated ores
Thickness
reduction
and folding
BIF
Hard Ore
Ore
BIF
Porous Ore
Maintainance
of Thickness
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5/15/2009
40% das reservas
martitic
30% das reservas
25% das reservas
criptohematítico--martítico
criptohematítico
specularitic-martitic
42