A, Vaughn

Stana, Regis

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Engineering Conferences International

Engineering Conferences InternationalECI Digital ArchivesBeneficiation of Phosphates VII ProceedingsSpring 2015Who Did What in Solvent Extraction ADemonstrated & Proven Technology for UraniumRecovery from Phosphoric AcidVaughn ARegis StanaFollow this and additional works at: http://dc.engconfintl.org/phosphates_viiPart of the Materials Science and Engineering CommonsThis Conference Proceeding is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion inBeneficiation of Phosphates VII by an authorized administrator of ECI Digital Archives. For more information, please contact franco@bepress.com.Recommended CitationVaughn A and Regis Stana, "Who Did What in Solvent Extraction A Demonstrated & Proven Technology for Uranium Recovery fromPhosphoric Acid" in "Beneficiation of Phosphates VII", P. Zhang, FIPR; J. Miller, Univ. of Utah; L. Leal, Univ. of Sao Paolo; A. Kossir,OCP Group; E. Wingate, Worley-Parsons Services Pty Ltd. Eds, ECI Symposium Series, (2015). http://dc.engconfintl.org/phosphates_vii/5There and Back Again 2.5  Who Did What in Solvent Extraction  A Demonstrated & Proven Technology for Uranium Recovery from Phosphoric Acid Vaughn Astley Regis Stana Beneficiation of Phosphates VII Melbourne, Australia  29th  March to 3rd April, 2015  There and Back Again 2.5 • History  • What we Know!  • Present!  • Future!! History....Two.5 Waves . History....The Waves • Started in 1950s, ended early 1960s – Emphasis on Military Stockpiling • Started late 1970s, ended 1990s – Nuclear Power • 2010s? – Nuclear Renaissance/ Era of Resource Conservation and Sustainability, Carbon Dioxide Mitigation • Renewed Interest in Uranium Supply. . P2O5  A Potential Major Source for Uranium • Phosphate Deposits Contain Uranium – Nature and Value of Deposits are in a Phase of Extreme Transition  • Uranium Recovery is a Well-Tested Additional Opportunity in Phosphoric Acid Production – Range: 0.1-7 Kg/Tonne of P2O5 – Typically: 0.3-0.6 Kg U per Tonne P2O5 – Price: Volatile, but in 2007, U3O8 Reached $300/KG – Currently About $90/Kg on Spot Market and $150/Kg for Some Long Term Contracts . History of Uranium Recovery .. First Wave • First Plant was Built in 1952 in Joliet Illinois.  It Precipitated the Uranium as a Phosphate  • Two Plants were Built in 1955 & 1957 in Florida.  These Used a Solvent Extraction Process (Octyl Pyro Phosphoric Acid)  • All Three Plants Operated until the Early 60s, when the Low Cost Production of Uranium from Western Mines Depressed the Price    . History of Uranium Recovery .. Second Wave • The Price of Uranium Increased Dramatically in the 1970s  • Eight new Plants were Built in the United States for the Recovery of Uranium From Phosphoric Acid  • Six were in Florida and Two were in Louisiana  • Plants were also Built in Canada, Spain, Israel, Belgium, Iran, Iraq, China  and Taiwan 00.511.5Millions of Kg of U3O81978 1982 1986 1990 1994 1998Uranium Recovered From Phosphoric Acid in the USATotal U3O8 Recovered Approximately 20 Million Kgs . Flow Sheets of Recent U.S.A. Plants Incoming 30% Acid Acid Pretreatment First Cycle Extraction First Cycle Strip Raffinate Post Treatment Pregnant  Solvent Barren  Solvent Strip Acid Loaded Strip Acid Second Cycle Extraction Second Cycle Strip Pregnant  Solvent Loaded  Strip Solution Precipitation of Uranium, Drying, and Calcining  Ship to  Converter  . Flow Sheets of Recent U.S.A. Plants • All Plants Extracted Uranium from Acid Produced by Di-Hydrate Processes (27-28% P2O5 Plus 1.5-3% Sulfate) • All Acids were Produced from Central Florida Rock • U3O8 Content of All Acids was About 0.5 Kg/Tonne P2O5 • All Used a Solvent Extraction Process • The Processes were Developed by Westinghouse, IMC (3 Plants), Uranium Recovery Corp., Freeport (2 Plants), and Gardinier . On Stream Factor and Recovery • Westinghouse Plant Operated With 98+ % On Stream Factor and 92+% U3O8 Recovery  – Turn Around After 2 Years and Down for Mechanical Problems Only • IMC Plants Operated at 92% On Stream Factor and 96% U3O8 Recovery  – Down Weekly for Line Scrubs and Yearly Turn Around) • Freeport Plants Operated at 92% On Stream Factor and 95% U3O8 Recovery  – (Down Weekly for Line Scrubs and Yearly Turn Around) . Annual U3O8 Capacity • IMC New Wales Plant Produced as Much as 591,000 Kg/Yr U3O8.   – CF Plant City Module Produced as Much as 409,000 Kg/Yr U3O8.   – One CF Plant Closed Down After Less than 3 Years of Operation   • Freeport Plants Produced as Much as 482,000 Kg/Yr U3O8. (Combined) . Plant / Design Freeport Gardinier IMC Uranium  Recovery Corp. Westinghouse Pretreatment Cooling No cooling 2-stage flash cooling - 32oC Spiral coolers  cool - 49oC No cooling Flash cool - 38oC Solids Removal Flocculant added before clarification Filtered using pressure leaf filters Clay /flocculant added before clarification Flocculant added before clarification Flocculant added before clarification Further Pretreatment None None Colour removal  -activated C None None Oxidation State Change Oxidised with oxygen Reduced with scrap Fe Oxidised with H2O2. Later O2 Reduced using ferro-silicon Oxidised using nitric acid First Cycle Solvent DEHPA/TOPO Octyl pyro-  phosphoric acid (OPPA) DEHPA/TOPO Octyl pyro- phosphoric acid (OPPA) DEHPA/TOPO Mixer Settler Design Low profile rectangular pumper-mixer settlers Rectangular pumper-mixer settlers Circular mixer settlers Deep-cone bottom settlers Low profile rectangular pumper-mixer settlers First Cycle Strip Solution 31% P2O5 acid plus iron 15% HF precipitated U as green salt 31% P2O5 acid plus sulphuric acid and iron 40% P2O5 acid plus hydrogen peroxide 27% P2O5 acid plus iron Second Cycle Oxidation State Change Oxidised with oxygen Dissolved in nitric acid Oxidised with H2O2. Later used oxygen No oxidation change required Oxidised using nitric acid Second Cycle Solvent DEHPA/TOPO TBP DEHPA/TOPO DEHPA/TOPO DEHPA/TOPO Uranium Precipitate Form Ammonium diuranate Ammonium diuranate Uranyl peroxide Ammonium uranyl tricarbonate Ammonium uranyl tricarbonate  . Capital Costs • Westinghouse Total Capital Cost was Less Than $20,000,000.  (About 20% of the Equipment was Not Used or Eliminated)  • IMC Total Capital Cost was About $200,000,000 (3 Plants),  (At Least 30% of the Equipment was Eventually Eliminated)  • URC Total Capital Cost was About $30,000,000   • Freeport Total Capital Cost was $40,000,000 for Uncle Sam and $30,000,000 for Faustina.  (About 10% of the Equipment was Eventually Eliminated)  • The Gardinier Capital Cost was About $25,000,000   Cash Costs / Kg • Westinghouse Total Cash Cost (Including Royalty, Cost of Acid Dilution, Losses and Reheat) was About $37/Kg U3O8 ($24/Kg w/o Royalty etc)  • IMC (New Wales) Cash Operating Costs (No Royalty, Dilution, Reheat or Loss Cost) was About $24/Kg U3O8  • URC Total Cash Cost (Including Royalty, Cost of Acid Dilution and Acid Losses) was About $100/Kg U3O8 (Low Throughput and Operating Factor)  • Freeport Cash Operating Costs (No Royalty, Dilution, Reheat or Loss Cost) was About $26/Kg U3O8  • Gardinier Cash Operating Cost was About $40/Kg U3O8 Present . “                                              “  Really The Future Wave  0.5?  . Opportunities to Reduce Cost of  “Next Generation” Plants  • Each of the Previous Plants had its Strong Points and Weak Points  • Combining the Best of Each will Reduce Both Capital and Operating Costs . Opportunities to Reduce Cost of  “Next Generation” Plants  • Some had 5 First Cycle Stages of Extraction, Whereas Others had 4.  • Some had 5 First Cycle Stages of Strip,  Whereas Others Had 3.  • Pretreatment Costs Varied by More than a Factor of Ten: ($0.50->$9.00/Kg U3O8)   Opportunities to Reduce Cost of  “Next Generation” Plants  • Solvent Losses Varied by Over a factor of Three:  ($4->$12/Kg U3O8)  • Total of Solvent Loss Cost and Pretreatment Cost Varied by Over a Factor of Three:   ($5.70->$17.00/Kg U3O8)    • Average Solvent Raffinate Concentrations Ranged From:  5 ppm to 100 ppm  • Solvent Loss Due to Settler Cleanings Ranged from   < 0.1 to > 0.5 Kg/tonne P2O5 Processed    Opportunities to Reduce Cost of  “Next Generation” Plants  • Oxidation Cost Ranged from $0.10 to $1.65/Tonne P2O5  • The Ratio of Fe+2/Fe  Added Ranged from Less Than 2 to over 3  • Second Cycle Operating Costs Were Similar, but One had a Significantly Lower Capital Cost and had Much Simpler  Chemistry.  . . Opportunities to Reduce Cost of  “Next Generation” Plants   • P2O5 Losses Ranged from <0.1% to ~1%  • Acid Dilution Ranged from Nil to >1%  • Strip Coefficients Ranged from 15 to 150  • Some Plants had Negative Impact on Fertilizer Production, Some Had Positive Impact Opportunities to Reduce Cost of  “Next Generation” Plants • During the Operation of the Plants, Studies were Conducted to Understand the Reasons for these Differences • Most were and are Well Understood • Most Significantly, the Causes of Crud Were Determined • Taking Advantage of this Understanding will Significantly Reduce Both the Capital and Operating Costs of the “Next Generation” Plants • Reductions as Much as 40% in Both Capital and Operating Costs Are Expected . • A New Optimal Complete Flow Scheme • Recent FEED Study Done………………. • Say a facility of 900,000 # U3O8/Yr,  (450,000 Kg/yr).  Capital ~$150MM  Operating Cost < $20/#, < $40/Kg  • Looks Very Good Indeed!!! What if we do the Best of the Best, & Avoid the Worst and the Failures. Risks • Most Fertilizer Producers are Concerned with the Effect the Uranium Recovery Plant Will Have on Their Operations – P2O5 Losses – Effect on Rubber Lined Equipment – Acid Dilution – Acid Reheat – Product Grade of Fertilizer Products • All These were Found to be Minimal or Positive in the Better Designed and Operated Plants    . • Using a New Optimal Complete Flow Scheme • Say a facility of 1,000,000 Kg U3O8/Yr, 2,200,000 #/yr.  • What Would Design be?  What if We Go Bigger!! 1,000,000 Kg U3O8/Yr, 2,200,000 #/yr • What Pre-Treatment to Use?  • Columns or Mixer/settlers?  • Secondary Extraction/ Stripping  • Many Other Opportunities  What Pre-Treatment  • This Area Has Very Significant Impact on Operational and Capital Costs. • Note: Prior Focus on Differing Pre-Treatment Philosophies in 80’s!! • A Preferred Method was used in the FEED study, and Would be In Future Recovery Projects. • Prior FEED Study @ 1MM#/yr Had: – 4 M/S FS Extractors, 24 x 4.9 x 1.2m – 3 M/S FS Strippers,   21 x 4.6 x 1.2m  • So for 1MMKg/Yr:- – Two Trains of M/S Required, 14 units • Allows any M/S to be taken Out of Service • Little impact on recovery as other units operating. • Recovery 96.97%   Columns or Mixer/Settlers • Columns Size Now Restricted to about 100,000 Kg/Yr U3O8 • Thus Need at Least 10 Extraction Columns • And Need at Least 5 Stripping Columns • Say 5 Trains needed, 2Ex, 1 Str, but More Costly and Less Flexible Than M/S’s.  • Recovery Comparable to M/S’s….~97%  Columns or Mixer/Settlers Secondary Extraction/ Stripping • Focus on Chemistry in secondary circuit and refinery. • Use Chemistry to Minimize Capital Cost. • Use Chemistry to Simplify the Operational Criteria. • Some Circuits Were Complex, others Very Simple.  • Best of the Best:-  • Using New Optimal Complete Flow Scheme  • Operating Cost < $18/#, < $36/Kg  • Should be a Winner!! 1,000,000 Kg U3O8/Yr, 2,200,000 #/yr Enhance the Uranium Level  • Enhance the uranium content of the acid that is produced by the phosphoric acid plant. • Yes.  Very Interesting Twist!!! Waste • As We Speak, the Phosphate Industry is “Throwing Away” Enough Uranium every Four Days to Fuel a Nuclear Power Plant for a Year!  . What About Hemi or 40% Clarified Acid?  • Octyl Phenol Phosphoric Acid Solvent has Been Demonstrated to Work Effectively in Lab  • Operating and Capital Costs will be about the Same per Pound as Central Florida  • Piloting Will be Required for any New Solvent or Acid Strength, and of course New Technology.  . Uranium from Phosphates • So How Much Uranium Can We Recover? •0 Kg • If We Procrastinate  • Been There  • Done That  • Like to do it Again, but Better!!  • Thank You  • vaughnastley@drphosphate.com 

Who Did What in Solvent Extraction A Demonstrated & Proven Technology for Uranium Recovery from Phosphoric Acid

https://dc.engconfintl.org/cgi/viewcontent.cgi?article=1006&amp;context=phosphates_vii

Who Did What in Solvent Extraction A Demonstrated & Proven Technology for Uranium Recovery from Phosphoric Acid

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