vaughn astley regis stana symphos 2013 agadir, morocco 6 th to 10 th may, 2013

There and Back Again 2.5

Who Did What in Solvent Extraction A Demonstrated & Proven

Technology for Uranium Recovery from Phosphoric AcidVaughn Astley

Regis StanaSymphos 2013

Agadir, Morocco

6th to 10th May, 2013

Our Backgrounds and Experience

.

– 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 HaveBackground and Experience

Regis & I HaveBackground 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 Waves1. 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.

.

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 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 AcidSecond 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 BuildingUR Plant Area 1 Hectare

.

Control Room

.

IMC Plant at New Wales

.

IMC Plant at New Wales

First Stage Mixer Settlers

Clarifiers and Carbon Columns

UR Plant Area 2.5 Hectares

.

0

0.5

1

1.5

Millions of Kg of U3O8

1978 1982 1986 1990 1994 1998

Uranium Recovered From Phosphoric Acid in the USA

Total U3

O8

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 AcidLoaded

Strip Acid

Second Cycle

Extraction

Second Cycle

Strip

Pregnant

Solvent

Loaded

Strip Solution

Precipitation of Uranium,

Drying, and Calcining

Ship to

Converter

.


• All Plants Extracted Uranium from Acid Produced by Dihydrate 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.


• Acid Pretreatment– Westinghouse Flash Cooled to 38 oC,

Clarified with Flocculent and Reheated to 40 oC

– IMC Used Spiral Coolers to Cool 49 oC, Added Clay and Flocculent Before Clarification, then Passed Acid Through Carbon Columns (Abandoned after 6 Years)

.


• 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 oC

Using 2 Stage Flash coolers and Clarified the Acid. The Acid was Reduced with Scrap Iron and then Filtered Using Pressure Leaf Filters

.


• 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)

.


• 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.


• 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

.


• First Cycle Stripping– Westinghouse Used 27% P2O5 Acid Reduced

with Scrap Iron Plus Powdered Iron Within Stages

– IMC Used 31% P2O5 Acid Plus Sulfuric with Iron Ball Towers for Each Stage for Reduction

– URC Used 40% P2O5 Acid Plus Peroxide– Freeport Used a Boosted Strength 31% P2O5

Acid With Iron Ball Towers for Each Stage for Reduction

– Gardinier Stripped the Solvent Using 15% HF

.


• 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.


• 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+% U3O8 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% U3O8 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% U3O8 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 U3O8.• 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

• URC Plant Produced About 45,000 Kg/Yr U3O8. • 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



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

.

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 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.

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

.


Plants • For Example– Solvent Losses Varied by Over a factor of Three ($4-

>$12/Kg U3O8) (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 U3O8) (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 U3O8) – 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.


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)– P2O5 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

<.1 to >.5 Kg/tonne P2O5 Processed– Some Equipment Remains From the Original Plants

and is Still Operating– Some Plants had Negative Impact on Fertilizer

Production, Some Had Positive Impact.


Plants • For Example– Oxidation Cost Ranged from $0.10 to

$1.65/Tonne P2O5

(Flow Sheet A the Lowest, Flow Sheet C the Highest)

– Fe+2/Fe Added ranged from < 2 to >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)..


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

• Been There

• Done That

• Thank You

vaughn astley regis stana symphos 2013 agadir, morocco 6 th to 10 th may, 2013

Documents

recovery of uranium

uranium recovery plants

history of uranium recovery

uranium recovery experience

uranium supply

imc plant

westinghouse plant

low cost production