1 Anthropogenic Induced Redox Disequilibrium in Uranium Ore Zones Richard Abitz, Savannah River...

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Anthropogenic Induced Redox Anthropogenic Induced Redox Disequilibrium in UraniumDisequilibrium in Uranium

Ore ZonesOre Zones

Richard AbitzRichard Abitz, , Savannah River National LaboratorySavannah River National Laboratory Bruce DarlingBruce Darling, , Southwest Groundwater Consulting, LLCSouthwest Groundwater Consulting, LLC

GSA 2010, Denver, Colorado

22

Drilling Issues Related to Redox Disequilibrium

Physical change to the ore minerals

1.E+06

1.E+07

1.E+08

1.E+09

1.E+10

1.E+11

1.E+12

1.E+13

0.0010.010.11101001000

particle diameter (um)

surf

ace

area

(u

m2 )

33

Drilling Issues Related to Redox Disequilibrium

Chemical reactions in the ore zone

7/2O2 + H2O + FeS2 → 2H+ + Fe++ + 2SO4--

½O2 + 2H+ + UO2 → H2O + UO2++

Airlift purge and pump adds O2

44

Mineral Dissolution Rates

General form of rate law (Lasaga, 1995)1:

Rate = k0*Amin*e-Ea/RT*anH+*g(I)*Πian

i*f(ΔGr)

Increase in both surface area (Amin) and O2 activity (an

O2) will increase dissolution rate.

1 Lasaga, A.C., 1995, Fundamental Approaches in Describing Mineral Dissolution and Precipitation Reactions, in Reviews in Mineralogy, Volume 31, Chemical Weathering Rates of Silicate Minerals, Mineralogical Society of America.

66UEC Permit UR03075

G arrison & C rouch (T A M U-C C , resea rch w eb s ite ) “T he G o liad F o rm a tion is a P liocene coasta l p la in com p lex cons is ting o f inc ised va lley , m eande ring fluv ia l, ba rrie r is land and beach , tida l de lta , lagoon , and flood p la in depos its… ”

77

UECPermitUR03075

Initial ISL targetis B Sand, yellow pattern

88

Production Test Wells (PTW), Sand B

0.001

0.010

0.100

1.000

PTW-1 PTW-2 PTW-3 PTW-4 PTW-5 PTW-6 PTW-7 PTW-8 PTW-9 PTW-10 PTW-11 PTW-12 PTW-13 PTW-14

Ura

niu

m m

g/L

Apr-08

Jul-09

Nov-09

URANIUM: Apr 2008: 0.005 to 0.804 mg/LJuly 2009: <0.003 to 0.090 mg/LNov 2009: <0.003 to 0.010 mg/L

99

Production Test Wells (PTW), Sand BARSENIC: Apr 2008: 0.001 to 0.022 mg/L

July 2009: <0.010 mg/LNov 2009: <0.010 mg/L

0.000

0.001

0.010

0.100

PTW-1 PTW-2 PTW-3 PTW-4 PTW-5 PTW-6 PTW-7 PTW-8 PTW-9 PTW-10

PTW-11

PTW-12

PTW-13

PTW-14

Ars

enic

m

g/L

Apr-08

Jul-09

Nov-09

1010

Production Test Wells (PTW), Sand BFUORIDE: Apr 2008: 0.50 to 0.79 mg/L

July 2009: 0.50 to 0.54 mg/LNov 2009: 0.50 to 0.69 mg/L

0.01

0.10

1.00

10.00


Flu

ori

de

mg

/L

Apr-08

Jul-09

Nov-09

1111

Production Test Wells (PTW), Sand BRADIUM: Apr 2008: 10 to 1,680 pCi/L

July 2009: 17 to 2,000 pCi/LNov 2009: 10 to 1,590 pCi/L

1

10

100

1000

10000


Rad

ium

pC

i/L

Apr-08

Jul-09

Nov-09

1212

B Monitor Wells (BMW), Sand BURANIUM: Apr 2008: <0.001 to 0.188 mg/L

July 2009: <0.003 to 0.006 mg/LNov 2009: <0.003 mg/L

0.000

0.001

0.010

0.100

1.000

BMW

-1

BMW

-2

BMW

-3

BMW

-4

BMW

-5

BMW

-6

BMW

-7

BMW

-8

BMW

-9

BMW

-10

BMW

-11

BMW

-12

BMW

-13

BMW

-14

BMW

-15

BMW

-16

BMW

-17

BMW

-18

BMW

-19

BMW

-20

BMW

-21

BMW

-22

Ura

niu

m

mg

/L

Apr-08

Jul-09

Nov-09

1313

B Monitor Wells (BMW), Sand BARSENIC: Apr 2008: 0.001 to 0.069 mg/L

July 2009: <0.010 mg/LNov 2009: <0.010 mg/L

0.000

0.001

0.010

0.100

BMW

-1

BMW

-2

BMW

-3

BMW

-4

BMW

-5

BMW

-6

BMW

-7

BMW

-8

BMW

-9

BMW

-10

BMW

-11

BMW

-12

BMW

-13

BMW

-14

BMW

-15

BMW

-16

BMW

-17

BMW

-18

BMW

-19

BMW

-20

BMW

-21

BMW

-22

Ars

enic

m

g/L

Apr-08

Jul-09

Nov-09

1414

B Monitor Wells (BMW), Sand BRADIUM: Apr 2008: 0.90 to 41 pCi/L

July 2009: 1.3 to 48 pCi/LNov 2009: 0.10 to 40 pCi/L

0.1

1.0

10.0

100.0

BMW

-1

BMW

-2

BMW

-3

BMW

-4

BMW

-5

BMW

-6

BMW

-7

BMW

-8

BMW

-9

BMW

-10

BMW

-11

BMW

-12

BMW

-13

BMW

-14

BMW

-15

BMW

-16

BMW

-17

BMW

-18

BMW

-19

BMW

-20

BMW

-21

BMW

-22

Rad

ium

p

Ci/

L

Apr-08

Jul-09

Nov-09

1515

Overlying Monitor Wells (OMW), Sand AURANIUM: Apr 2008: 0.006 to 0.014 mg/L


1.00E-03

1.00E-02

1.00E-01

OMW-1 OMW-2 OMW-3 OMW-4 OMW-5 OMW-6 OMW-7 OMW-8 OMW-9

Ura

niu

m

mg

/L

Apr-08

Jul-09

Nov-09

1616

Overlying Monitor Wells (OMW), Sand AARSENIC: Apr 2008: 0.010 to 0.031 mg/L


0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035


Ars

enic

m

g/L

Apr-08

Jul-09

Nov-09

1717

Overlying Monitor Wells (OMW), Sand ARADIUM: Apr 2008: 0.5 to 6.0 pCi/L

July 2009: 0.2 to 3.2 pCi/LNov 2009: 0.4 to 1.0 pCi/L

0.1

1

10


Rad

ium

p

Ci/

L

Apr-08

Jul-09

Nov-09

1818

Uranium solubility as a function of Eh

0.00001

0.0001

0.001

0.01

0.1

1

10

100

-0.2 -0.15 -0.1 -0.05 0 0.05

Eh (volts)

Ura

nium

(m

g/L)

coffinite uraninite

Coffinite Uraninite

EPA DW limit

Solubility of Uranium Ore Minerals in Sand B Groundwater (solid, pH=7.18; dashed, pH=7.96)

Apr-08

Jul-09

Nov-09

1 Anthropogenic Induced Redox Disequilibrium in Uranium Ore Zones Richard Abitz, Savannah River...

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