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.
55
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
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
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
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
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
July 2009: 0.003 to 0.013 mg/LNov 2009: 0.009 to 0.012 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
July 2009: 0.005 to 0.010 mg/LNov 2009: 0.005 to 0.010 mg/L
0.000
0.005
0.010
0.015
0.020
0.025
0.030
0.035
OMW-1 OMW-2 OMW-3 OMW-4 OMW-5 OMW-6 OMW-7 OMW-8 OMW-9
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
OMW-1 OMW-2 OMW-3 OMW-4 OMW-5 OMW-6 OMW-7 OMW-8 OMW-9
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