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GOLDEN SUNLIGHT
May 2011May 2011
Barrick - Golden Sunlight MineMine Design, Operation and
Closure Conference
Golden SunlightMine
Golden Sunlight Mine
Golden Sunlight Mine
East Waste Rock Dump Complex
Tailings Impoundment #2
Tailings Impoundment #1
West Waste Rock Dump Complex
Mineral HillOpen Pit
I-90
Hwy 69
Hwy 2
Mill Site
Water Management
During OperationUse as makeup water for mill circuitMajor sources
• Pit• Tailings Impoundment #1 containment wells
Water Management
ClosurePump – Treat - DischargeMajor sources
• Pit• Tailings Impoundment #1 containment wells• Tailings Impoundment #2 drain-down
Water Types
Pit Water–ARD signature
• Low pH, sulfate, iron, trace metals, and TDS
Tailings Impoundment Waters–Process water residuals
• Cyanide, thiocyanate, nitrate, ammonia, and TDS• Slight signature of neutralized ARD
Treatment
Pit Water–Active HDS type treatment (pH adjustment, metals precipitation), possibly polishing for TDS removal.
Tailings Impoundment Water–Active biological treatment (aerobic and anaerobic), possibly followed by HDS and polishing for TDS removal.
Biological Treatment Desired Reactions:Aerobic
CN + Bacteria HCO3 + NH3
SCN + OH + Bacteria SO4 + HCO3 + NH3
NH3 + Bacteria NO2 + Bacteria NO3 (nitrification)
AnaerobicNO3 + CH3OH + Bacteria CO2 + N2 (g) + OH
(denitrifaction)
Adsorption and Absorption of Heavy Metals
Passive Biological Treatment
Acknowledgementso Jim Whitlock – Whitlock and Associates
oChris Nelson – Barrick Golden Sunlight Mine
oRory Tibbals and Shannon Dunlap
oRick Henderson and Tom Monfortan – Barrick Golden Sunlight Mine
oKathy Gallagher - SPSI
Pilot Plant Testing Down flow columns constructed in GSM mill facility
- 42 inch diameter and 14 foot height
Counter current air flow (convective)
Inert rock media used (1/4 - 5/8 inch nominal size)
Tailings Impoundment #2 reclaim water used for testing
Flow rate - 3 gallons/day/ft2
Inoculated
Pilot Test Results 96 % removal of cyanide
98-99% removal of thiocyanate
Nearly complete nitrification
Anaerobic column used to effectively denitrify
98-99% removal of copper (19 ppm to 1 ppm)
Slight decrease in TDS
pH relatively unchanged at approximately 8 s.u.
Heap Treatment• One acre limestone based pad on a synthetic liner
• Limestone - 20% > 1.5”, 50% > 1” and 70% < ¾”
• Buried drip line distribution system
• Counter current convection air in heap
• Flow rate - 3 gallons/day/ft2
• Soda ash (alkalinity) and phosphate added to influent
• Source water - T1 containment well water
Heap Test Results
0
50
100
150
200
250
300
350
12/19/2002 12/19/2003 12/19/2004 12/19/2005 12/19/2006 12/19/2007 12/19/2008
Thio
cyan
ate
(mg/
L)
Heap Test - Thiocyanate
Influent Effluent
Heap Test Results
0
5
10
15
20
25
30
35
12/19/2002 12/19/2003 12/19/2004 12/19/2005 12/19/2006 12/19/2007 12/19/2008
Total Cyanide
(mg/L)
Heap Test – Total Cyanide
Influent Effluent
Heap Test Results
0
5
10
15
20
25
30
35
40
45
50
12/19/2002 12/19/2003 12/19/2004 12/19/2005 12/19/2006 12/19/2007 12/19/2008
Am
mon
ia (
mg/
L -
N)
Heap Test - Ammonia
Influent Effluent
Heap Test Results
0
5
10
15
20
25
30
35
40
45
50
1/9/2003 1/9/2004 1/9/2005 1/9/2006 1/9/2007 1/9/2008 1/9/2009
Nit
rate
(m
g/L
-N
)
Heap Test - Nitrate
Influent Effluent
Heap Test Results
0
5
10
15
20
25
3/18/2003 3/18/2004 3/18/2005 3/18/2006 3/18/2007 3/18/2008 3/18/2009
Cop
per
(mg/
L)
Heap Test - Copper
Influent Effluent
Heap Test Results
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
4/19/2004 4/19/2005 4/19/2006 4/19/2007 4/19/2008 4/19/2009
Ars
enic
(m
g/L)
Heap Test - Arsenic
Influent Effluent
Heap Test Results
1500
2000
2500
3000
3500
4000
4500
3811
0
3817
1
3823
3
3829
4
3835
5
3841
4
3847
5
3853
6
3859
8
3865
9
3872
0
3877
9
3884
0
3890
1
3896
3
3902
4
3908
5
3914
4
3920
5
3926
6
3932
8
3938
9
3945
0
3951
0
3957
1
3963
2
3969
4
3975
5
3981
6
3987
5
3993
6
3999
7
4005
9
4012
0
TDS
(mg/
L)
Heap Test - Total Dissolved Solids
Influent Effluent
Heap Test Results
Heap treatment can significantly reduce cyanide and thiocyanate concentrations
Heap treatment can reduce metal and metalloid concentrations
A single stage heap did not demonstrate complete nitrification
Short circuiting due to plugged drip line filters was a problem
Temperature effects on small heap reduced performance, particularly for nitrification
Single stage heap could not meet WQ standards
Heap Treatment
Larger heaps could mitigate temperature effects
A second stage heap could likely remove more cyanide and thiocyanate as wells have complete nitrification
TDS is a problem – some sulfate could be removed in an anaerobic denitrification treatment step
Heap treatment could reduce phytotoxicity for land application
Heap treatment has the potential for a low capital and operating cost water management tool
Questions ?
(None – Thank You)
Jim Whitlock
“A number of research people have tried to make this process(es) work without much success, probably because it is art as well as science. ”
“If your audience wants to contact me with questions, that is fine as well.”