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Global and Turkish P erspectives of Thorium F uel for N uclear E nergy

Global and Turkish P erspectives of Thorium F uel for N uclear E nergy. Prof. Dr. Muammer Kaya Osmangazi University Mining Engineering D epartment , Eskişehir- Turkey. Natural Properties of Thorium ( Th ) ( Earth’s Forgotten Treasure ). Occurs naturally ,

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Global and Turkish P erspectives of Thorium F uel for N uclear E nergy

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  1. Global and Turkish Perspectives of Thorium Fuel for NuclearEnergy Prof. Dr. Muammer Kaya Osmangazi University MiningEngineeringDepartment, Eskişehir-Turkey

  2. NaturalProperties of Thorium (Th) (Earth’sForgottenTreasure) • Occursnaturally, • Identifiedalmosttwocenturiesago, • Exists in naturealmostentirely as stableTh-232 isotope, • Thitselfcannotsustain a nuclearchainreaction, • Is a lustroussilvery-white metal, • Is dense andonlyslightlyradioactiveactinides, you can carry a lump of it in yourpocketwithoutharm (lessradiotoxic), • Th is fertilematerial, accept a neutronandtransmuteintofissile U-233 anddecaystostablePb-208. • Th is usually a by-product of the REE containgmonaziteorbastnasiteminerals.

  3. THORIUM BASICS (New GreenNukeNuclearRenaissance) • Is plentiful in natureandvirtuallyinexhaustablefuel. • Is a thermalbreeder (i.e. createsenoughnewfuel as it breaksdowntosustain a high-temperaturechainreactionindefinitely). • It is impossibletomakenuclearweaponsand/orbombsfromThbyterrorists (i.e. peaceful) • Nuclearpowerwithoutproliferation has obviouspoliticalappealforgovernments. • Has a highheatcapacity (i.e. smallerreactors) • Does not requirecostlyminingand mineral processingmethods (i.e. lessexpensive), • Is extraordinallyefficientnuclearfuel (i.e. allowslongerfuelburn-up) • Producesmoreneutronspercollision; thus 20-40 timesmoreenergy is generated, lessfuelconsumedand 47 timeslessradioactivenastiesleftbehind. • Thfuel is completelyusedup in thereactor; thus, there is relativelylittlenuclearwaste. • Thwasteneedsto be storedforonlyfewhundredyears (as long as 300 years) not for a fewthousand (10000 years) like U wastes. • Threactors has zero risk of meltdown as opposedto U reactors. • Threactors can useliquidfuelwhich has significantadvantages in operation, controlandprocessingoversolidfuels. • Liquidfuelsworks at hightemperaturewithoutpressurization. “Thshould be heart of thenations’ atomicpowereffort”

  4. WHY Thorium ?(New Era of Safe, CleanandAffordableEnergy) There is a treat of climatechange, There is an urgentdemandforcarbon-freeenergy/electricity. • Th is 3-4 timesmoreabundantthan U in natureanddistrubutedevenly in mostcountries in theworld. • Th can be minedwithrelativelylow-costandenvironmentfriendlyminingmethodsfromhighgradealluvialdeposits. • Thextraction is relativelystraightforward. • Th has a betterradiationstabilityandlongerfuelcycle. • Th has a higherenergydensityandfueleconomy. • Thwasteshave a lessradiotoxicperiodduetoabsence of transuranicwastes (i.e. Pu, Np, CeandAm). • Thmixedoxide (TMOX (Pu+Th)) fuel can be burned in anyreactorthat is lisencedtouse MOX. • There is a hugespenttoxicmaterial/plutoniumthat has beingpiledupfrom U-fuel. Thfuel can be usedtosafelyincineratetheseunwantedstockpiles. Global energyneedsforoneyear can be suppliedbyapproximately 6600 tons of Th.

  5. URANIUM (Today’sproblematicnuclearfuel) • Today’spreferedfuel in commercialreactors, • U has beenadequatetomeettoday’ssupplyneeds, • Reserve: 5.5*106tons; YearlyProduction: 65*103tons, • Producers: 19; Life Expectancy: 50-60 years • U oresaregenerally not harmful, but is dangerouslytoxictohumansifingested, inhaledoreven of prolongedcontact. • Reactorsrequiresexteremelyrare235U (0.7%) whichmust be purified/ enrichedfromnatural238U. • U mining, enrichmentandextractionareexpensiveandcomplex, • U-fuelleaveslargeamount of toxicwastescontainingPu-239 that can be used in makingbombsandweapons, • Theused/depletedfuel can be reprocessedbyexpensivePu-U extraction (Purex) processtoremovefissilematerialandrefabricatenewfuelelements, R&D on U willfadeaway in favour of Th.

  6. ReasonablyAssuredReserves (RAR) andEstimatedAdditionalReserves (EAR) of thoriumbyOECD/NEA, NuclearEnergy, "Trends in NuclearFuelCycle", Paris, France (2001). (http://en.wikipedia.org/wiki/Thorium)

  7. ThcontainingRareEarthElements(REE)s • Phosphate Mineral Formula Density (g/cm3) MagneticPropertyWeight (%) • REO ThO2 UO2 • Monazite (Ce) (Ce, La, Nd, Th)PO4 4.98-5.43 Paramagnetic 35-71 0-20 0-16 • Monazite (La) (La, Ce, Nd, Th)PO45.17-5.27Paramagnetic 35-71 0-20 0-16 • Monazite (Nd) (Nd, Ce, La, Th)PO4 5.17-5.27 Paramagnetic 35-71 0-20 0-16 • Silicate Mineral Formula Density (g/cm3) MagneticPropertyWeight (%) • REO ThO2 UO2 • Thorite (Th, U) SiO4 6.63-7.20 Paramagnetic <3 - 10-16 • Carbonate Mineral Formula Density (g/cm3) MagneticPropertyWeight (%) • REO ThO2 UO2 • Basnasite (Ce) (Ce, La,Th)(CO3)F4.90-5.20 Paramagnetic 70-74 0-0.3 0.09 • Basnasite(La) (La, Ce, Th)(CO3)FParamagnetic70-74 0-0.3 0.09 • Basnasite(Y) (Y)(CO3)F3.90-4.00 Paramagnetic70-74 0-0.3 0.09

  8. MONAZITE (REE-Th PO4) • A phosphate mineral withRareEarthOxide (REO) content of 70% (Ce, La, Pr andNd). • Monazite is found in granites, syanites, pegmatites, beachsandsetc. • Worldmonaziteresourcesareestimatedto be about 12 milliontons. • Includes 3-14% Thandvariableamount of U. • Found in placerdeposites, beachsandsand is also a component of the Bayan Obodeposit in China. • Worldmonaziteproduction is between 5000-6000 tons/y. • MajorMonaziteproducersareMtWeld (Australia), (AndhraPradesh, TamilNuda, Odisha) IndiaandGuandong (China), MalaysiaandBrazil.

  9. ThO2MiningfromMonazite • Thfrommonazitedeposits can be minedwithrealtivelylow-costandenvironmentfriendlyminingmethods, because it exists in highconcentrationsand in high-grades at thesurfaceor in beachsands. • Theore/sand can be skimmedoffthesurfacebydredgemining. • Monazitemining is moreeconomicaldueto presence of Th as a by-product in the REE ore. • U mine can be developed in 10-15 years, Th mine can be developed in 2-3 yearsduetolessrequlatoryscrutiny. • ThO2 is liberatedfrommonazitebygravitational, magneticandelectrostaticconcentrationmethods, employing a minimum of dangerouschemicals (i.e. acids). Whereas U is minedbyexpensive underground miningand in-situacidleachingmethods.

  10. BEACH SAND (Quartz, Garnet, Magnetite, Zircon, Ilmenite, Rutile, Monazite) L: light D: Dense F: Ferromag. NM: Nonmag. M: Mag. T:Thrown P: Pinned Quartz: 2.7 (L) Garnet:3.5 (L) Magnetite: 5.5-6.5 (D, F) Zircon: 4.6-4.7 (D, NM, P) Rutile: 4.2 (D, NM, T) Ilmenite: 4.5-5.0 (D, M, T) Monazite: 4.9-5.2 (D, M, P) ligth heavy Typical beach sand treatment flowsheet. REEs+Th

  11. BASTNASITE (REE-ThFCO32) • A fluorocarbonate mineral with a REO content of approximately 70% (Ce, La, Pr and Nd). • Basnasite is theprimarysource of ligthREOsandaccountsfor 80% of theoverallamount of REO in theworld. • Inthelast 50 yearsbasnasitereplacedmonazite as a chief mineral source of REEs. • Basnasite has been extracted on a large scale only in Mountain Pass, USA and Bayan Obo, China (supply 45% of worlddemand). • Expensive underground miningmethodsareused. • Processingdepends on finegrinding; gravity, magneticandflotationseparations; calcination, HClleachingandsolventextractionsteps.

  12. UraniumandThoriumDeposits of Turkey BlackSea Eskisehir Ankara Sivrihisar-EskisehirLigth REE+ThDeposit MediterraneanSea

  13. Comparison of some REO DepositsaccordingtoReserve Size Typical TREO content 1st Quartile 11. Kaynak: Greenfields Research Ltd; (Data: Company websites)

  14. ThO2contents of some REO Deposits 3. Kaynak: Greenfields Research Ltd; Data: Company websites

  15. ReserveDevelopmentStudies in Eskişehir-Sivrihisar-KızılcaörenLightREEs+ThField • Firstreservecalculationsdepended on 50-200 m deepdrillingstudies in 1959. • In 2011, two 500 m deepdrillingboreswereopened. • Analysesshowedfurtherreserves at deeps. • In 2012; 10,000 m drillingwereperformed at 38 locations. • Between 2014 and 2017; 116,000 m drillingwill be performed at 289 locations. • 45,000 sampleswill be takenforgeochemicaland 1,000 sampleswill be takenby XRD analyses. Explorationwithdrilling Drillingcores

  16. Eti Mines Eskişehir-Sivrihisar Deposit’sOperation Plan • OreProperties • Production Plan Depositdiscoveredusingairprospectingsurveyby General Directorate of Mineral ResearchandExploration of Turkey (MTA) in 1959. OperatinglicenseownedbyTurkish GovernmentMiningCompany of Eti Minesfor 10 years

  17. MONOZITE CRACKING/OPENING WITH HOT CONCENTRATED H2SO4 Ammoniumoxalate Th+REOs RE oxalates Filtering Thhas beenextractedfrommonazitethrough a complexmulti-stageprocess (AMEX). Monazite is dissolved in 120-150 oC hot concentrated H2SO4forseveralhours. Th is extracted as an insoluableresidueinto an organicphasecontaing an alkyl amine. Then it is separated/ strippedusing an ionsuch as nitrate, chloride, hydroxideorcarbonatereturningThto an aqueousphase. FinallyTh is precipitetedandcollected. Thextraction is a complexprocessbecause of similarchemicalpropertieswithREOs.

  18. THORIUM CONCENTRATION FLOWSHEET • ORE • HNO3or H2SO4 LEACHING (pH:1.2) • Precipitation of someimpurities • SolventExtraction (SX) orIon Exchange (IE) • Th(NO3)4.nH2O • Drying (105 oC, 20h) Water • Th(NO3)4 • Calcination (575oC) • ThO2 concentrate ION EXCHANGE RESINE BEADS

  19. EFFECTS OF ROASTING and THIOUREA ADDITION on BASTNASITE LEACHING (Yörükoğulları, Obut, Girgin, 2002 and 2003) 1. Pre-concentration Scrubbing (75% solids, N: 2060 rpm, t: 15 min.) BaSO4 FlotationPre-Concentrate (21.3% REO) CaF2Flotation 2. BastnasitePre-ConcentrateLeach Particle Size: 0.053 mm N: 450 rpmREEs in solutionwereanalysedby ICP spectrometer. Baandhigh S/L: 1/20 g/mL t: 6 hoursconcentration REE wereanaysedbygravimetricmethodsbased on sulphateandoxalateprecipitation. 2a. LeachingwithoutRoastingusingConcentratedAcids 8M HNO3 70oC 100% total REE dissolution 15 M H2SO4 25oC 89.25% 2.5M HCl 55oC 82.2% 2b. Roasting+DiluteAcidLeaching Afterroasting at 750oC for 1 h, leachingwith 1-3M H2SO4 at 25oC. (RoastingdecomposescarbonatesandoxidizeCe). Total REE contentsforunroasted: 18.59%, roasted: 22.00% androasted+leached 47.4%. 2c. Roasting+DiluteAcidLeachingandThioureaAddition(extractingagentforAu, Agand REE) Thioureaconc.: 0-2 M and 1-3 M H2SO4 Roastedwithoutthiourea: 17.6% REE dissolutionRoastedwiththiourea: 89.0% dissolution (at 3M H2SO4and 1M thiourea) 3. Hydroxide-OxalateMixturePrecipitation (Mish metal) fromLeachSolution+ Heatingto 900oC for 2 hours Total REE 93.6%, REO: 92.6%

  20. EFFECTS OF ROASTING and THIOUREA ADDITION on BASTNASITE LEACHING (Yörükoğulları, Obut, Girgin, 2002 and 2003) • Roastingdecomposestheflurocarbonatestructure of REEs in thepreconcentratewiththeformation of fluoceriteandcerianite as newphases (XRD results). • Thischange in compositionincreasestheselectivedissolution of lanthanumandneodymium in H2SO4solutioncausing 5.6 timesincrease in the total REsdissolution. • Addition of thiourea (CS(NH2)2) totheleachingmediumincreasesthedissolution of total REEs in theunroastedandespecially in theroastedpreconcentratereaching a dissolution of 89%. • 92.6% mixed REO precipitationwith H2SO4-thioureamediumwasachived.

  21. PİLOT SCALE ACID LEACH and SOLVENT EXTRACTION TESTSforREEsandThfromESKISEHIR ORE byMTA (2004) Run-of-mine oresfrom 3 districts RotatingFurnace Blending OxidizingRoasting JawCrusher 3M HClacidleach ConeCrusher Filtration RollCrusher Cake FiltrateSolution Flotation Oxalateprecipitation REOs+ThO2 Particle size: - 1mm; OxidizingRoastingTemperature: 600-900oC; t: 1-6 hours Leach: 3 M H2SO4 REE dissolution: 86% (Ce, La, Nd ve Th) and 3 M HClREE dissolution: 92% (Ce, La, Nd ve Th) (89% REO mishmetal) OxalatePrecipitation: ThGrade: 98.7% , ThRecovery: 98% 84% CaF2 93% BaSO4 98.7% Th(N03)4 84.2% Ln(OH)3 84%CeO2

  22. TheEffects of Particle Size andRoasting Time on ThoriumRecoveryduringH2SO4andHClLeaching(Yorukoglu et.al., 2012) • Sample: 3 t representativehomogenized • ParticleSizesTested: 0.065, 0.2, 1 and 3 mm • OxidizingRoastingTemp. and Time: 900 oCand 1, 3 and 6 hours • Leaching: 3 M H2SO4and 3 M HCl, 3 h, 25oC, separately • LeachingRecovery: (REEs + Th) % R = 73%, 1 mm, 3 h R = 79%, 1 mm, 1h 3 M H2SO4 3 M HCl

  23. TheEffects of ParticleSize andRoasting Time on ThoriumRecoveryduringH2SO4andHClLeaching(Yorukoglu et.al., 2012) • 3 M H2SO4 givesbetterleachingrecoverythanHCl. • H2SO4 is cheaperthanHCl. • Oxidizingroasting at 900 oC at 1 hour, beforeathmosfericleaching is necessary. • Thebestparticle size forleaching is 1 mm. • 79% (REEs+Th) dissolution can be achieved.

  24. CONCLUSIONS from TURKEY’S POINT OF VIEW • Energy is majorconcernfordevelopingTurkishsociety. Turkeytodayexportsmorethan 70% of itsenergy as fossilfuels. Inthelast 50 years, Turksaresceptical, anxiousandindecisiveabouthavingnuclearenergy. • Inthelast 10 years, wearebringingThintoTurkishgovernment’sattentionandnationaldiscussion as a new, safe, clean, affortable, CO2-free, alterternative, strategicanddomesticnuclearenergyfuel. • InTurkey, wearetryingtofindfundstosupporteducationand R&D on Th. WeareexpectingtoestablishThoriumResearchCenter /ThoReC) in TurkeyforThmining+enrichment+extraction+fuelfabrication+prototypereactortesting+nuclearfuelcycletesting. • Turkeyrecentlycontactedfour VVER-1200 typeRussianNuclearPowerReactorsusing U as a fuelin Akkuyu (Rosatom) andanotherfourunitswill be established in Sinop in thenextdecadebyJapan (Mitsubishi-Westinghouse). WewillenforcegovernmenttouseThalongwith U as an alternativefuel in thenewreactors. • IfTurkey can processit’simportantdomesticlowgradebastnasiteresource in EskisehirforTh, it can suppyitsownThfuelformorethan 100 yearsandbecome self-sufficient in energysources.

  25. THANKS FOR YOUR INTEREST

  26. ComparingReactors Richard Martin (2009) * equvalentenergyfrom 3.5 milliontons of coal

  27. Dünya enerji ihtiyacını toryum tek başına 6600 ton ile karşılayabilecektir.

  28. REE andThare in fine size fraction

  29. HClLeaching of Sivrihisar BastnasiteOre (Gülmez et.al., 2012) • Sample: 3 t representativehomogenized • ParticleSizesTested: 0.065, 0.2, 1 and 3 mm • Leaching: 3 M H2SO4andHCl, 3 h, 25oC, separately • LeachingRecovery: 92.09 % (REE + Th) • Mishmetalconcentrate: 73.8% REE/89.4%REO (saleable) ChemicalAnalyses of CompositeSample HClLeachingTailingChemicalAnalyses

  30. Comparison of some REO Depositsaccordingto REO Grades

  31. MONAZITE ALKALINE CRACKING andAUTOCLAVING WITH NaOH ThrecoveryfrommonaziteusuallyinvolvesleachingwithNaOH at 140oC followedbycomplexprocessestoprecipitatepure ThO2 Hot 73% NaOHsolution is usedtocrack/openmonazitesand. Afteraddition of coldwaterNa-phosphate is removedfromthesolution. REO andTh(OH)4 in solidresiduewereleachedwithHCl(pH: 3-4) . Dewateredmishmetal RE chloridesareproducedwithelectroliticreduction. Usingliquid-liquidextractionwithChelatingreagents can give 99.99% pureproducts.

  32. THORIUM CONCENTRATION STUDIES BEDRI IPEKOGLU (Ph.D Thesis, 1983) ACID TOREX PROCESS ThO2recoveryfromused (U233/Th) fuel Hot acidleach (13M HNO3, 0.05M HF, 0.1M Al nitrat at boilingtemperature) CentrifugingSolidresidue Th(NO3)4 + UO2(NO3)2 Solution SX Columns Purification SİVRİHİSAR-ESKISEHIR ORE GRAVITY CONCENTRATION MAGNETIC CONCENTRATION FLOTATION ACID LEACHING Optimum Conditions: HCldosage: 200kg/t Leaching Time: 3 hours ThGrade: %99 Tributylphosphate (TBP)

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