Presentation on theme: "There and Back Again 2.5 Who Did What in Solvent Extraction A Demonstrated & Proven Technology for Uranium Recovery from Phosphoric Acid Vaughn Astley."— Presentation transcript:
There 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 Symphos 2013 Agadir, Morocco 6 th to 10 th May, 2013
. –I had Technical and Development Responsibility for Freeport Agrico Uranium Extraction Plants at Uncle Sam and Faustina from 1982 to 1995 –Rege with Westinghouse R&D, Worked on Several Processes for Recovery of Uranium from WPA Acid and other Sources (Including IX and Membranes) ….. Three Years at Operating Plant –Hired By IMC in 1981 to “Fix” their Uranium Recovery Plants One Complete Plant at New Wales Two First Cycles at Two CF Plants) Regis & I Have Background and Experience
–In 1993 IMC and Freeport Agrico Merged Giving Rege and I Access to Each Others Uranium Recovery Experience. What was done that did not work. What did work. What we would not do again. What would a better design encompass. –Extensive Performance and Cost Data for All 4 Plants over their Operational Years –Contacts With The People that Ran These Facilities –We are Concerned About Loss of This Memory..
The Three Waves 1. Started in 1950s, ended early 1960s – Emphasis on Military Stockpiling 2. Started late 1970s, ended 1990s – Nuclear Power 3. 2010s? – Nuclear Renaissance/ Era of Resource Conservation and Sustainability, Carbon Dioxide Mitigation 4. Renewed Interest in Uranium Supply..
P 2 O 5 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 P 2 O 5 –Typically: 0.3-0.6 Kg U per Tonne P 2 O 5 –Price: Volatile, but in 2007, U 3 O 8 Reached $300/KG –Currently About $90/Kg on Spot Market and $150/Kg for Some Long Term Contracts.
History of Uranium Recovery from Phosphoric Acid: First Wave First Plant was Built in 1952 in Joilet 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 from Phosphoric Acid 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.
Westinghouse Plant at Farmland Industries First Stage Mixer Settlers Refinery Building UR Plant Area 1 Hectare.
First Stage Mixer SettlersClarifiers and Carbon Columns UR Plant Area 2.5 Hectares.
Total U 3 O 8 Recovered Approximately 20 Million Kgs.
Flow Sheets of Recent U.S.A. Plants Incoming 30% Acid Acid Pretreatment First Cycle ExtractionFirst 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 Dihydrate Processes (27-28% P 2 O 5 Plus 1.5-3% Sulfate) All Acids were Produced from Central Florida Rock U 3 O 8 Content of All Acids was About 0.5 Kg/Tonne P 2 O 5 All Used a Solvent Extraction Process The Processes were Developed by Westinghouse, IMC (3 Plants), Uranium Recovery Corp., Freeport (2 Plants), and Gardinier.
Flow Sheets of Recent U.S.A. Plants Acid Pretreatment –Westinghouse Flash Cooled to 38 o C, Clarified with Flocculent and Reheated to 40 o C –IMC Used Spiral Coolers to Cool 49 o C, Added Clay and Flocculent Before Clarification, then Passed Acid Through Carbon Columns (Abandoned after 6 Years).
Flow Sheets of Recent U.S.A. Plants Pretreatment (Contd) –URC Did Not Cool, and Clarified Only –Freeport Did Not Cool, but Added a Flocculent and Clarified –Gardinier Cooled the Acid to 32 o C Using 2 Stage Flash coolers and Clarified the Acid. The Acid was Reduced with Scrap Iron and then Filtered Using Pressure Leaf Filters.
Flow Sheets of Recent U.S.A. Plants Oxidation Change –Westinghouse Used Nitric Acid to Oxidize Acid (and Uranium) –IMC Used Hydrogen Peroxide (Later Changed to Oxygen) to Oxidize Acid (and Uranium) –URC Used Ferro Silicon to Reduce Acid (and Uranium) –Freeport Used Oxygen to Oxidize Acid (and Uranium).
Flow Sheets of Recent U.S.A. Plants Uranium Extractant Solvents –Westinghouse Used DEPA/TOPO –IMC Used DEPA/TOPO –URC Used Octyl Pyro Phosphoric Acid –Freeport Used DEPA/TOPO Mixer Settler Design –Westinghouse Used Holms and Narver Low Profile Pumper/Mixers/Rectangular Settlers –IMC Used Circular M/S –URC Used Deep Cone Bottom Tank M/S –Freeport Used Low Profile Pumper/Mixers & Racked Rectangular M/S.
Flow Sheets of Recent U.S.A. Plants CRUD –When Any Organic Solvent is Mixed with Wet Process Phosphoric Acid, a Third Interfacial Phase is Formed that is Termed “Crud” or “Gunk”. –It Must be Removed from the Settlers or it will Interfere with the Performance of the Settler –“Crud” Contains About 50% Solvent, so the Solvent Must be Recovered Crud Removal –Westinghouse Continuously Over Flowed Crud from First Settler and Intermittently Pumped from the Rest –IMC Pumped Crud From All Circular Settlers –URC Batch Overflowed Crud From Settlers –Freeport Used Interface Drag Devices to Pull Crud Out of Settlers.
Flow Sheets of Recent U.S.A. Plants Crud Processing –Westinghouse Used Centrifuge (Abandoned) and Pre Coat Vacuum Drum Filter –IMC Initially Used Plate and Frame Filters and then Pre Coat Vacuum Drum Filter –URC Used Centrifuges and Pre Coat Vacuum Drum Filter –Freeport Used Chemical Treatment, a Patented Centrifuge Separation, and a Crud Maker System.
Flow Sheets of Recent U.S.A. Plants First Cycle Stripping –Westinghouse Used 27% P 2 O 5 Acid Reduced with Scrap Iron Plus Powdered Iron Within Stages –IMC Used 31% P 2 O 5 Acid Plus Sulfuric with Iron Ball Towers for Each Stage for Reduction –URC Used 40% P 2 O 5 Acid Plus Peroxide –Freeport Used a Boosted Strength 31% P 2 O 5 Acid With Iron Ball Towers for Each Stage for Reduction –Gardinier Stripped the Solvent Using 15% HF.
Flow Sheets of Recent U.S.A. Plants Second Cycle Oxidation –Westinghouse Used Nitric Acid to Oxidize Acid (and Uranium) –IMC Used Hydrogen Peroxide (Later Changed to Oxygen) to Oxidize Acid (and Uranium) –URC First Cycle Acid Was Already Oxidized –Freeport Used Oxygen to Oxidize Acid (and Uranium) –The Gardinier Process Did not Require Oxidation.
Flow Sheets of Recent U.S.A. Plants Second Cycles –All Plants (Except Gardinier) Used DEPA/TOPO in Second Cycle with Rectangular Mixer Settlers for Extraction and Strip –All Used Ammonium Carbonate for Stripping –Each Precipitated the Uranium as an Ammonium Compound –All Calcined to a Black Oxide and Shipped in 55 Gallon Drums.
Operating Experience with Plants Westinghouse Plant Operated With 98+ % On Stream Factor and 92+% U 3 O 8 Recovery –Turn Around After 2 Years and Down for Mechanical Problems Only –Organic Advance was Being Increased to Increase Recovery to 96% when Price of Uranium Dropped and Plant Closed IMC Plants Operated at 92% On Stream Factor and 96% U 3 O 8 Recovery (Down –Weekly for Line Scrubs and Yearly Turn Around).
Operating Experience with Plants URC Plant Operated at Less Than 60% On Stream Factor and Less than 80% Recovery (Lots of Mechanical Problems and Problems with Crud Build Up) Freeport Plants Operated at 92% On Stream Factor and 95% U 3 O 8 Recovery (Down Weekly for Line Scrubs and Yearly Turn Around) The Gardinier Plant Obtained About 90% Recovery.
Operating Experience with Plants Westinghouse Plant Produced Over 137,000 Kg/Yr U 3 O 8. IMC New Wales Plant Produced as Much as 591,000 Kg/Yr U 3 O 8. CF Plant City Module Produced as Much as 409,000 Kg/Yr U 3 O 8. One CF Plant Closed Down After Less than 3 Years of Operation URC Plant Produced About 45,000 Kg/Yr U 3 O 8. Freeport Plants Produced as Much as 482,000 Kg/Yr U 3 O 8. (Combined).
Economics of Previous Plants 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.
Economics of Previous Plants Westinghouse Total Cash Cost (Including Royalty, Cost of Acid Dilution, Losses and Reheat) was About $37/Kg U 3 O 8 ($24/Kg w/o Royalty etc) IMC (New Wales) Cash Operating Costs (No Royalty, Dilution, Reheat or Loss Cost) was About $24/Kg U 3 O 8 URC Total Cash Cost (Including Royalty, Cost of Acid Dilution and Acid Losses) was About $100/Kg U 3 O 8 (Low Throughput and Operating Factor) Freeport Cash Operating Costs (No Royalty, Dilution, Reheat or Loss Cost) was About $26/Kg U 3 O 8 Gardinier Cash Operating Cost was About $40/Kg U 3 O 8.
Economics of Previous Plants Operating Labor Requirements Flow Sheet A Required 5 Shift Supervisors, 4 Chief Operators, and 2 Operators. Flow Sheet B Required 3 Shift Supervisors, 4 Chief Operators, 5 Operators and 2 Laborers. Flow Sheet C Required 1 Shift Supervisor, 2 Chief Operators, 1 Operator and 1 Laborer. Flow Sheet E Required 2 Shift Supervisor, 2 Chief Operators, 3 Operators and 3 Laborers..
Opportunities to Reduce Cost of “Next Generation” Third Wave Plants Each of the Previous Plants had its Strong Points and Weak Points. Combining the Best of Each can Reduce Both Capital and Operating Costs.
Opportunities to Reduce Cost of “Next Generation” Third Wave Plants For Example –Solvent Losses Varied by Over a factor of Three ($4->$12/Kg U 3 O 8 ) (Flow Sheet C the Lowest, Flow Sheet A the Highest) –Pretreatment Costs Varied by More than a Factor of Three. ($0.50->$9.00/Kg U 3 O 8 ) (Flow Sheet A the Lowest, Flow Sheet B the Highest) –The Total of Solvent Loss Cost and Pretreatment Cost Varied by Over a Factor of Three ($5.70->$17.00/Kg U 3 O 8 ) –Flow Sheets A and C Required 5 First Cycle Stages of Extraction Whereas Flow Sheet B Only Required 4 –Flow Sheet A Required 5 First Cycle Stages of Strip, Whereas Flow Sheets C and B Only Required 3. –Both Flow Sheets A and C Experienced “Reduced Extraction Coefficients” (Solvent Poisoning), Flow Sheet B did not.
Opportunities to Reduce Cost of “Next Generation” Third Wave Plants For Example –Average Solvent Concentrations in the Raffinate Ranged From 5 ppm to 100 ppm (Flow Sheet C the Lowest, Flow Sheet A the Highest) –P 2 O 5 Losses Ranged from <0.1% to ~1% –Acid Dilution Ranged from Nil to >1% –Strip Coefficients Ranged from 15 to 150 (Flow Sheet B the Lowest, Flow Sheet C the Highest) –Solvent Loss Due to Settler Cleanings Ranged from.5 Kg/tonne P 2 O 5 Processed –Some Equipment Remains From the Original Plants and is Still Operating –Some Plants had Negative Impact on Fertilizer Production, Some Had Positive Impact.
Opportunities to Reduce Cost of “Next Generation” Third Wave Plants For Example –Oxidation Cost Ranged from $0.10 to $1.65/Tonne P 2 O 5 (Flow Sheet A the Lowest, Flow Sheet C the Highest) –Fe+2/Fe Added ranged from 3 (Flow Sheet B the Lowest, Flow Sheet D the Highest) –Second Cycle Operating Costs Were Similar, but One had a Significantly Lower Capital Cost (Flow Sheet B the Lowest)..
Opportunities to Reduce Cost of “Next Generation” Third Wave Plants During the Operation of the Plants, Studies were Conducted to Understand the Reasons for these Differences Most are Well Understood Most Significantly, the Causes of Crud Were Determined Taking Advantage of this Understanding can 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 Likely.
Estimates of Current Operating Costs Third Wave Current Operating Costs Will be Higher Due to: –Lower Uranium Content of Rock (for Central Florida Plants) (0.50 Kg/Tonne Previously to Estimated 0.40-0.45 Kg/Tonne for Next 10 Years) –Somewhat Higher Solvent Cost –Higher Electricity Cost –Higher Labor Cost (Can be Offset with Automatic Controls) –Total Cash Operating Costs Should be Less than $40/Kg –+ Regulations ??? $.
Estimates of Current Capital Costs Capital Costs (Adjusted for Inflation) Should Be Lower than Previous Plants, but Highly Dependent on Flow Sheet Adopted.
What if we do the Best of the Best and Avoid the Worst and the Failures. Say a facility of 1,000,000 # U3O8/Yr, 450,000 Kg/yr. FEED Study………………. Capital $100MM to $150MM Operating Cost < $20/#, < $44/Kg Looks Good, Eh!!!!!!!
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.
Risks Not Much Detail Has been Published On the Plants from the Previous Generation Many Documents Have Been Destroyed for Legal Reasons or from Neglect Most of the “Know How” is in the Memories and Personal Archives of a Diminishing Number of Key People Average Age of the Most Knowledgeable People is in the 70s We Are Probably Losing “Know How” and Operational Expertise at the Rate of 10%/yr Relearning this Information Would Cost Several 10’s of Millions of Dollars.
Risks The Most Effective Way to Capture this Valuable Knowledge is to Build a “Re- Demonstration Plant” as Quickly as Possible. Training Programs For Those Interested. The Second Most Effective Way to Capture this Valuable Knowledge is to Conduct in Depth Interviews with the Key People 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% Clarifies 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 fro any New Solvent or Acid Strength..
Other Opportunities New Solvents –Octyl-Phenol-Phosphoric Acid Lower Cost Higher Extraction Coefficient Many Others have been reported New Contactors –Columns New Technology –Ion Exchange –Ultrafiltration –Micro-emulsions –Chelating Agents –Computer Controls.
Uranium from Phosphates So How Much Uranium Can We Recover? 0 Kg If We Procrastinate