Unconventional uranium resources - Indian scenario By Anjan Chaki Director Atomic Minerals Directorate for Exploration and Research Department of Atomic Energy Government of India “Uranium from Unconventional Resources” IAEA theme meeting, Vienna, 3 – 6 November, 2009
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Unconventional uranium resources - Indian scenario · PDF fileUnconventional uranium resources - Indian scenario By ... Kaladgi basin, Karnataka ... dolomite, sandstone, shale, conglomarate
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Unconventional uranium resources- Indian scenario
By
Anjan ChakiDirector
Atomic Minerals Directorate for Exploration and ResearchDepartment of Atomic Energy
PreviewUranium provinces Indian scenarioPhosphorites U.P., Uttarakhand and Rajasthan statesCambrian Black shales Himachal Pradesh and UttarakhandMonazite East and West coasts of IndiaLignite ash Tamil Nadu statePlaya sediments Semi-arid to arid regions of RajasthanConcluding remarks Present status of investigations and future plans
USGS open file report No. 02-156-A (2002) has listed more than 65 occurrences of phosphorites in India.Of these, 55 occurrences are sedimentary phopsphorite deposits and 10 are magmatic deposits Nearly half a dozen more apatite occurrences associated with carbonatites are knownAmong the 55 sedimentary phosphorite occurrences, 9 aresignificant deposits having more than 2m thickness and extending over more than 2 km strike length.
Bijawar phosphoritesArea Hirapur-MardeoraDistrict Chattarpur and Sagar districts of Madhya
PradeshGeology Part of Bijawar Group of rocks in the Bijawar
basin. Overly the Bundelkhand granitoids and underly the Vindhyan Super Group sediments
Stratigraphy Occur at the upper parts of the basin (Gangau formation) along with conglomarate, dolomite, sandstone, shale, conglomarate and basic volcanics
Extension Occur as four horizons of varying dimension from 220 – 1400m. Thickness from 1 to 35m
Nature Reddish brown, fine grained with 15 -48% P2O5
Exploitation Being exploited by State mining corporation for fertilisers
Uranium content 100 ppm. Systematic evaluation not doneRemarks Potential deposit for exploitation
GEOLOGICAL MAP OF MUSSOORIE SYCLINE, DEHERADUN AND TEHRI-GARHWAL DISTRICT, UTTRAKHAND
DOLERITEOLIVE SHALE AND SHALE MARLQURTZITE MEMBERCALCAREOUS MEMBERARENACEOUS MEMBERARGILLACEOUS MEMBERCHERT MEMBER (CHERT AND PHOSPHORITE UNITS)LIMESTONE AND DOLOMITEPHYLLITES, SCHISTOS, QUARTZITE
1Km 0 2 4Km
INDEX
KROL FORMATION
LOWER TAL FORMATION
UPPER TAL FORMATIONSUBATHU FORMATION
STRIKE & DIP OF BEDDING
FAULTTHRUST
STRIKE & DIP OF FOLIATION
DARAK
After GSI
DOLERITEOLIVE SHALE AND SHALE MARLQURTZITE MEMBERCALCAREOUS MEMBERARENACEOUS MEMBERARGILLACEOUS MEMBERCHERT MEMBER (CHERT AND PHOSPHORITE UNITS)LIMESTONE AND DOLOMITEPHYLLITES, SCHISTOS, QUARTZITE
INDEX
KROL FORMATION
LOWER TAL FORMATION
UPPER TAL FORMATIONSUBATHU FORMATION STRIKE & DIP OF BEDDING
FAULT
THRUST
STRIKE & DIP OF FOLIATION
GEOLOGICAL MAP OF MUSSOORIE SYNCLINE, DEHRADUN AND TEHRI-GARHWAL DISTRICTS, UTTARAKHAND
---------------------- Main Central Thrust ------------------------------500Ma(early Cambrian)
Tal Group Koti Dhamam formation- ArenaceousSankjholi formation- Arenaceous and argillaceousShalian formation (Carbonaceous shale, Phosphorites and Cherts)
Krol Group Krol- A (shale Carbonate facies)Infra Krol (Argillaceous facies)
650Ma(Neo Proterozoic)
Blaini Group Boulder bed (Tillite facies)
---------------------- Main Boundary Thrust ------------------------Tertiary Siwalik Group Sandstone – shale sequence
Mussoorie PhosphoritesArea MussoorieDistrict UttarakhandGeology Lower Tal Group of Cambrian sediments of Lesser
Himalayas. Occur in association with Carbonaceous shale and Chert.
Stratigraphy Occur between Garhwal (MCT) and Krol (MBT) thrustsExtension Extend for nearly 75km. Phosphorites are 1 to 5m
thick. Uranium mineralisation is restricted to the bottom 1.5m of the phosphorite horizon. In general uranium mineralisation confined to the Phosphorites, Chert and Black shale association.
Nature Fluorapatite (collophane) and DahliteExploitation Not exploited by so farU3O8 content 200 - 980ppm. Uranium concentration is high because
of the intimate association of carbonaceous shaleRemarks Environmentally fragile. Steeply dipping syncline
Lower Proterozoic Aravalli Super Group Nathdwara GroupDolomite and schistphosphoritesJharol GroupQuartzite and phyllitesUdaipur GroupConglomarate, phyllite, schist andStromotalites
Area KirouliDistrict Udaipur district, RajasthanGeology Nathdwara Group of Aravalli Super Group of Lower
Proterozoic ageStratigraphy Occur at the lower part of the Aravalli Super GroupExtension Extend for 2.5km. 10 major lenses of phosphorites
from 10x1m to 30x50m delineated in cherty brecciated limestone.
Nature Sand size phosphate set in a matrix of microcrystalline phosphate and limonite with an average 17% P2O5
Exploitation Not exploited so farU3O8 content 260 to 840 ppmRemarks Low P2O5 content and mode of occurrence of phosphorite as pockets inhibits its exploitation
Monazite content in beach sand generally ranges from 0.02 – 0.88%. The higher concentrations up to 5% are confined to very few places along Tamil Nadu and Kerala coasts.
Aeolian Teri sands of Tamil Nadu contain 0.02 to 0.11% monazite.
Riverine placers of Siri river, Chattisgarh state contain 0.6 to 0.8% monazite.
Average ThO2 content : 9%ThO2 resource in monazite : 963,900 tonnesTh Metal = 847,268 tonnes
Average U3O8 content in monazite: 0.3%U3O8 resource in monazite : 32,130 tonnesU Metal = 26,989 tonnes
Average REO content : 60%REO resources = 6,426,000 tonnesFor every tonne of REO produced from monazite co-production of ThO2 will be 150 kgU3O8 will be 0.006 kg.
Monazite Resources - 10.70 million tonnes
REO in Monazite : 60%La2O3: 23%, CeO2: 46%, Nd2O3: 20%, Pr6O11: 5.5%, Sm2O3: 2.5% and other REO: 3%.
In view of modest U and abundant Th resources, India has planned to use thorium in the 2nd and 3rd stages of the nuclear power programme.
Monazite at present is separated as by-product of ilmenite mining at Manavalakurichi, Chavara on the west coast and Chatrapur on the east coast.
GEOLOGICAL MAP OF MUSSOORIE SYCLINE, DEHERADUN AND TEHRI-GARHWAL DISTRICT, UTTRAKHAND
DOLERITEOLIVE SHALE AND SHALE MARLQURTZITE MEMBERCALCAREOUS MEMBERARENACEOUS MEMBERARGILLACEOUS MEMBERCHERT MEMBER (CHERT AND PHOSPHORITE UNITS)LIMESTONE AND DOLOMITEPHYLLITES, SCHISTOS, QUARTZITE
1Km 0 2 4Km
INDEX
KROL FORMATION
LOWER TAL FORMATION
UPPER TAL FORMATIONSUBATHU FORMATION
STRIKE & DIP OF BEDDING
FAULTTHRUST
STRIKE & DIP OF FOLIATION
DARAK
After GSI
DOLERITEOLIVE SHALE AND SHALE MARLQURTZITE MEMBERCALCAREOUS MEMBERARENACEOUS MEMBERARGILLACEOUS MEMBERCHERT MEMBER (CHERT AND PHOSPHORITE UNITS)LIMESTONE AND DOLOMITEPHYLLITES, SCHISTOS, QUARTZITE
INDEX
KROL FORMATION
LOWER TAL FORMATION
UPPER TAL FORMATIONSUBATHU FORMATION STRIKE & DIP OF BEDDING
FAULT
THRUST
STRIKE & DIP OF FOLIATION
GEOLOGICAL MAP OF MUSSOORIE SYNCLINE, DEHRADUN AND TEHRI-GARHWAL DISTRICTS, UTTARAKHAND
Carbonaceous shales of Lesser HimalayasArea Krol belt, Lesser HimalayasDistrict States of Uttarakhand and Himachal PradeshGeology Part of Cambrian Tal Group Group of rocks
sandwiched between the Main Boundary thrust and Main Central Thrust of the Himalayas. Disposed in five major synclines Viz. Nigali Dhar, Korgai, Mussoorie, Garhwal and Nainital synclines.
Stratigraphy Occur at the Lower parts of the Tal Group as Carbonaceous shale-Phosphorite-Chert association
Extension The belt runs for more than 300km. Thickness of black shale from 1 to 130m
Nature High organic content and presence of pyrite Exploitation Not exploitedUranium content 20 to 390ppm. Systematic evaluation not doneRemarks Fragile Himalayan belt
High organic content and presence of pyrite in black shales. Organic matter acts as a powerful reductant and maintains the reducing environment which protects the mineralization from oxidation and remobilisation.Major components of black shales are silica and clay minerals, Organic matter, sulfides, and carbonate. No discrete uranium mineral is recordedU occurring in adsorbed state on sapropelic organic matter and also associated with phosphate- bearing mineral, fluorapatiteHigh biological productivity during Cambrian might have played an important role in uranium concentration in black shales. Cyanobacterial mats form physical traps to remove Uranium from solutions.
coal ash, specifically ash from lignite burning coal plants located in areas where the lignite contains higher than normal levels of uranium. Since uranium oxides are not flammable, the uranium oxide gets left behind in the ash, so there is a potential that it will contain commercially useful quantities of uranium -something close to few hundred parts per million that is generally considered interesting.
Miocene Lignites of South Arcot , Tamilnadu and of Kerala
Oligocene to Upper Eocene Jaipur, Nazira and Makum coalfields of Assam ; Namchick and Namphuk coalfields of Arunachal Pradesh
Middle Eocene Lignites of Palana, Rajasthan and Kutch
Lower Eocene Coals of Darranggiri, Rongrenggiri in the Garo Hills; Cherapunji, Mawlong and Nongstoin in Meghalaya, Mikir Hills in Upper Assam, and Coals of Jammu coalfields– Kalkot, Metka, Mahogala, Chakar Dhanwal Sawalkot-Lodhra, Kura and Chinkah
Upper Gondwana Coalfields
Upper Jurassic Chikiala and Kota in the Kota Stage in Maharashtra ; Satpura region in Jabalpur, Madhya Pradesh; Ghuneri in Kutch below the Umia Stage
Upper Permian Raniganj, Jharia, Bokaro and Karanpura coalfields of the Damodar valley in West Bengal and Bihar
Lower GondwanaCoalfields
Lower Permian All Lower Gondwana coalfields of the Indian Peninsula, including Damodar Valley, Mahanadi Valley, Brahmani Valley, Son Valley, Pench-Kanhan Valley, Pranhita - Godavari Valley and Wardha Valley, coalfields of Himalayas; Darjeeling district of W. Bengal; Ranjit Valley of Sikkim; Abur, Daphla and Aka hills of Arunchal Pradesh
Uranium investigations in Cuddalore formationSouth eastern part of Indian peninsula is exposed with NE-SW trending detached outcrops of Gondwana-Cretaceous-Tertiary-Quartenery sediments overly granitoid basement rocks and extend over 300km.
The Miocene Cuddalore sandstones comprise major argillaceous sandstone, fire clay, laterite and Lignite seams of 8-24m thickness
14 -700ppm uranium in lignite with few values of upto 1000ppm
Neyveli Lignite Corporation Limited is a Government owned lignite mining company administered through the Ministry of Coal. NLC operates the largest open pit lignite mines in India and mines around 24 million tonnes of lignite per year for the thermal power stations with an installed capacity of 2490 Mw of electricity per year.
NLC has expanded its project to Rajasthan to exploit the lignite resources for thermal power production.Lignites of Cuddalore sandstone (Miocene) contains 25-35% of carbon, 46-50% of moisture, 15% organic compounds and around 4 - 5% mineral ash.
2 to 540ppm uranium values recorded in the lignites of Neyveli
Ash content of Neyveli lignite is 4 to 5%A presumed average 100ppm of U3O8 in the lignite ash makes 120 tonnes U3O8 in the annual production of lignite ash
Proposed to investigate the pit containing nearly fifty years of ash for uranium extraction by heap leaching.
Ash pit has the potential to produce significant uranium.
Uranium in playa Sediments The term ‘Playa’ is used to refer to flat and generally barren portions of the arid basins of usually internal and closed drainage that periodically flood and accumulate detrital and evaporite sedimentsThere are about 50,000 playas in the world of which about 1000 have areas greater than 100 sq kmUraniferous playa deposits have been located in South Africa, Australia and Chile. No deposit of this type was known earlier to contain sufficient mineralisation to constitute a viable depositRecently, M/s. Uranex has identified the ‘Bahi Project’ in Tanzania which contains an estimated resource of 3000 tonnes U3O8 at an average grade of 218 ppm U. Uranium is found in unconsolidated playa/lake sediments in amorphous form in cracks and on grain surfaces and occurs within top 20 m of lake.
Average 60ppm of uranium in the top 5m of unconsolidated sediments (clay and silt) above water tablePlaya sediments rich in calcite, gypsum and halite.Uranium concentration increases below water tableBrine well water samples in the lake contain 466-2072ppb uraniumUranium occur in the cementing material of sedimentsNo carnotite reported in the uraniferous playa sediment samplesLow Eh, alkaline pH and high content of uranium in the lake water facilitate Uranium deposition with the playa sedimentsplaya sediments appear to be 20,000 years and younger
Concluding remarksIndian Phosphorite deposits with relatively low P2O5content in general do not make this attractive for phosphoric acid and uranium production
Uranium from Indian monazites is a viable option
Exploitation of uranium from lignite ash is a workable proposition
Extensive uraniferous black shale deposits of Himalayas contain low grade uranium
Uraniferous playas of Rajasthan state could be an interesting option in the near future, needs further exploration