Antamina Mine Water Management Model Alan Keizur Golder Associates Roberto Manrique Arce
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Antamina Mine Water Management Model Alan Keizur Golder Associates Roberto Manrique Arce Compañia Minera Antamina User Conference 2006 Background The Antamina mine, located at over 4,300 m elevation in the Peruvian Andes, is one of the world’s top ten producers of both copper and zinc. In 2002, a GoldSim model was developed by Golder Associates to provide Antamina with a forecasting tool to assist with water management system operations. Key Model Components •Concentrator – given ore type and tonnage, the model calculates the volume of tailings slurry produced, including solids, free water, and pore water •Climate – generates daily precipitation values according to the specified scenario (historical, Monte Carlo, or annual dryness condition). Lake evaporation is based on measured monthly averages, and runoff is calculated using the Australian Water Balance Model (AWBM). The input parameters for the runoff model were calibrated to match measured values in each of the major catchments. •Tailings Pond – calculates volume and elevation in the tailings pond given previous values and daily inflows and outflows. Major inflows include tailings slurry (consisting of free water, pore water, and solids), runoff, direct precipitation, and inter-basin transfers. Major outflows include pumping for concentrator reclaim, transfers to polishing pond, evaporation, and seepage that is collected and (optionally) discharged. •Other Storage Ponds – three other storage facilities are included in the model: Dam D (fresh water storage), Nescafe (flood control and fresh water storage), and the polishing pond (flood control and dilution or tailings pond water) •Diversion Ditches – route water from one location to another •Receiving Waters – calculates necessary releases to meet instream flow requirements Objectives for the Model Antamina developed the GoldSim model to meet the following objectives: Develop and confirm the water balance for the tailings basin and test under different conditions (climatic and operational). •Provide useful projections of volume, elevation, and flow rate for the Tailings Dam, main upstream dams (Dam D, Polishing Pond, Nescafe Lake) downstream water systems (Tucush Creek and Ayash River) in the short, middle, and long-term. Based on the above the GoldSim model results are used to support operational decisions, such as: Assessment for the dam raise plan (e.g. probable maximum flood (PMF) compliance) and support for dam management (e.g. tailings deposition plan, pond water volume trends). Calculate tailings deposition rates under different concentrator operating scenarios (ore type, throughput) Assess the impact of certain management decisions (e.g., tailings seepage return line into Tucush wetlands, replacement of batch water loads in pipeline with Dam D fresh water, etc.) Observations and Future Directions The following observations and conclusions can be drawn from the work to date: •The Antamina Water Management Model is operational and adequately represents the actual site conditions. •GoldSim is a very effective platform for implementing this type of model The next phase of model development may include the following: •A preliminary model for an additional basin was constructed, but not maintained due to rapid site changes. This may be revised once the system stabilized. •A new module may be added to simulate concentrate transfer and operations at an associated port facility. Typical Simulation Scenarios Antamina personnel run the model on a regular basis to assist with planning and operation of the water management system. Model runs are typically done deterministically based on specified scenarios, such as the following: •Time Frame – typically one month to 5 years •Precipitation – 100-year wet, 100-year dry (based on statistical analysis of long-duration records from nearby climate stations), or historical average precipitation (based on measured data at the site since 2000) •Transfers from Tailings Pond to Polishing Pond – specify decision rules for making transfers to the polishing pond for dilution and eventual discharge. •Seepage Pumpback – specify decision rules for managing collected seepage, which can be pumped back to the tailings pond, discharged directly, or pumped to a passive treatment system (wetlands) •Tailings Production – various production rates and ore types can be analyzed. •Release of fresh water to maintain instream flows – releases from the three fresh water storage ponds can be either specified or calculated to ensure minimum flows are maintained in the Quebrada Ayash. Water Management System Diagram Figure 4:Dam C rest and Pond Elevation Trends forD ifferentConcentratorThroughputR ates 4,055 4,065 4,075 4,085 4,095 4,105 4,115 4,125 01/01/2006 01/01/2007 01/01/2008 01/01/2009 01/01/2010 01/01/2011 01/01/2012 01/01/2013 01/01/2014 01/01/2015 01/01/2016 01/01/2017 01/01/2018 01/01/2019 01/01/2020 01/01/2021 01/01/2022 Elevation (m asl) Projection 2006 -2022 Dam Crest Envelopes 4075 4090 4100 4105 4120 125000 tpd 100,000 tpd 85,000 tpd Figure 5:Dam D W aterElevation Envelopes Operational Level (Spillw ay Invert) 4,230 4,235 4,240 4,245 4,250 4,255 4,260 01/01 / 2 0 0 6 15/01/ 2 0 0 6 29 /01/2006 12 /02/ 2 006 26/02/2006 12/03/2006 26/03 /200 6 09/04 /20 0 6 23/04 /20 0 6 07/05 /20 0 6 21/05 /20 0 6 04/06 /20 0 6 18/06 /20 0 6 02/07/20 0 6 16/07/20 0 6 30/07/200 6 13/08 / 2 0 0 6 27/08/2006 10/09/2006 24/09/2006 08/10/2006 22 /10/ 2006 05 /11/2006 19 /11/2 006 03/12/2006 17/12/20 0 6 31/12 /20 0 6 Elevation (m asl) 0% 20% 40% 60% 80% 100% Percentage ofTotal Volum e 100 YearDryConditions Max. Oscilation Standart C onditions M ax. O scilation 100 YearW et Conditions Max. Oscilation Current Elevation D am D Minim um Elevation forStandart Year Minim um Elevation 1 in 50 DryYear Minim um Elevation 1 in 100 D ryYear Standart conditions without R iparian Release Under100 yeardry conditions, the pond trend is full dry-up Projection 2006
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Antamina Mine Water Management Model Alan Keizur Golder Associates Roberto Manrique Arce Compañia Minera Antamina. Background - PowerPoint PPT Presentation
Transcript of Antamina Mine Water Management Model Alan Keizur Golder Associates Roberto Manrique Arce
Antamina Mine Water Management Model
Alan KeizurGolder Associates
Roberto Manrique ArceCompañia Minera Antamina
User Conference 2006
BackgroundThe Antamina mine, located at over 4,300 m elevation in the Peruvian Andes, is one of the world’s top ten producers of both copper and zinc. In 2002, a GoldSim model was developed by Golder Associates to provide Antamina with a forecasting tool to assist with water management system operations.
Key Model Components•Concentrator – given ore type and tonnage, the model calculates the volume of tailings slurry produced, including solids, free water, and pore water
•Climate – generates daily precipitation values according to the specified scenario (historical, Monte Carlo, or annual dryness condition). Lake evaporation is based on measured monthly averages, and runoff is calculated using the Australian Water Balance Model (AWBM). The input parameters for the runoff model were calibrated to match measured values in each of the major catchments.
•Tailings Pond – calculates volume and elevation in the tailings pond given previous values and daily inflows and outflows. Major inflows include tailings slurry (consisting of free water, pore water, and solids), runoff, direct precipitation, and inter-basin transfers. Major outflows include pumping for concentrator reclaim, transfers to polishing pond, evaporation, and seepage that is collected and (optionally) discharged.
•Other Storage Ponds – three other storage facilities are included in the model: Dam D (fresh water storage), Nescafe (flood control and fresh water storage), and the polishing pond (flood control and dilution or tailings pond water)
•Diversion Ditches – route water from one location to another
•Receiving Waters – calculates necessary releases to meet instream flow requirements
Objectives for the ModelAntamina developed the GoldSim model to meet the following objectives:
Develop and confirm the water balance for the tailings basin and test under different conditions (climatic and operational).
•Provide useful projections of volume, elevation, and flow rate for the Tailings Dam, main upstream dams (Dam D, Polishing Pond, Nescafe Lake) downstream water systems (Tucush Creek and Ayash River) in the short, middle, and long-term.
Based on the above the GoldSim model results are used to support operational decisions, such as:Assessment for the dam raise plan (e.g. probable maximum flood (PMF) compliance) and support for dam management (e.g. tailings deposition plan, pond water volume trends).Calculate tailings deposition rates under different concentrator operating scenarios (ore type, throughput)Assess the impact of certain management decisions (e.g., tailings seepage return line into Tucush wetlands, replacement of batch water loads in pipeline with Dam D fresh water, etc.)
Observations and Future DirectionsThe following observations and conclusions can be drawn from the work to date:
•The Antamina Water Management Model is operational and adequately represents the actual site conditions.
•GoldSim is a very effective platform for implementing this type of model
The next phase of model development may include the following:
•A preliminary model for an additional basin was constructed, but not maintained due to rapid site changes. This may be revised once the system stabilized.
•A new module may be added to simulate concentrate transfer and operations at an associated port facility.
Typical Simulation ScenariosAntamina personnel run the model on a regular basis to assist with planning and operation of the water management system. Model runs are typically done deterministically based on specified scenarios, such as the following:
•Time Frame – typically one month to 5 years
•Precipitation – 100-year wet, 100-year dry (based on statistical analysis of long-duration records from nearby climate stations), or historical average precipitation (based on measured data at the site since 2000)
•Transfers from Tailings Pond to Polishing Pond – specify decision rules for making transfers to the polishing pond for dilution and eventual discharge.
•Seepage Pumpback – specify decision rules for managing collected seepage, which can be pumped back to the tailings pond, discharged directly, or pumped to a passive treatment system (wetlands)
•Tailings Production – various production rates and ore types can be analyzed.
•Release of fresh water to maintain instream flows – releases from the three fresh water storage ponds can be either specified or calculated to ensure minimum flows are maintained in the Quebrada Ayash.
Water Management System Diagram
Figure 4: Dam Crest and Pond Elevation Trends for Different Concentrator Throughput Rates
4,055
4,065
4,075
4,085
4,095
4,105
4,115
4,125
01/01
/2006
01/01
/2007
01/01
/2008
01/01
/2009
01/01
/2010
01/01
/2011
01/01
/2012
01/01
/2013
01/01
/2014
01/01
/2015
01/01
/2016
01/01
/2017
01/01
/2018
01/01
/2019
01/01
/2020
01/01
/2021
01/01
/2022
Elev
atio
n (m
asl)
Projection 2006 - 2022
Dam Crest Envelopes
4075
4090
4100
4105
4120125000 tpd
100,000 tpd
85,000 tpd
Figure 4: Dam Crest and Pond Elevation Trends for Different Concentrator Throughput Rates
4,055
4,065
4,075
4,085
4,095
4,105
4,115
4,125
01/01
/2006
01/01
/2007
01/01
/2008
01/01
/2009
01/01
/2010
01/01
/2011
01/01
/2012
01/01
/2013
01/01
/2014
01/01
/2015
01/01
/2016
01/01
/2017
01/01
/2018
01/01
/2019
01/01
/2020
01/01
/2021
01/01
/2022
Elev
atio
n (m
asl)
Projection 2006 - 2022
Dam Crest Envelopes
4075
4090
4100
4105
4120
Figure 4: Dam Crest and Pond Elevation Trends for Different Concentrator Throughput Rates
4,055
4,065
4,075
4,085
4,095
4,105
4,115
4,125
01/01
/2006
01/01
/2007
01/01
/2008
01/01
/2009
01/01
/2010
01/01
/2011
01/01
/2012
01/01
/2013
01/01
/2014
01/01
/2015
01/01
/2016
01/01
/2017
01/01
/2018
01/01
/2019
01/01
/2020
01/01
/2021
01/01
/2022
Elev
atio
n (m
asl)
Projection 2006 - 2022
Dam Crest Envelopes
4075
4090
4100
4105
4120125000 tpd
100,000 tpd
85,000 tpd
Figure 5: Dam D Water Elevation Envelopes
Operational Level (Spillway Invert)
4,230
4,235
4,240
4,245
4,250
4,255
4,260
01/01
/2006
15/01
/2006
29/01
/2006
12/02
/2006
26/02
/2006
12/03
/2006
26/03
/2006
09/04
/2006
23/04
/2006
07/05
/2006
21/05
/2006
04/06
/2006
18/06
/2006
02/07
/2006
16/07
/2006
30/07
/2006
13/08
/2006
27/08
/2006
10/09
/2006
24/09
/2006
08/10
/2006
22/10
/2006
05/11
/2006
19/11
/2006
03/12
/2006
17/12
/2006
31/12
/2006
Elev
atio
n (m
asl)
0%
20%
40%
60%
80%
100%
Perc
enta
ge o
f Tot
al V
olum
e
100 Year Dry Conditions Max. Oscilation Standart Conditions Max. Oscilation 100 Year Wet Conditions Max. Oscilation
Current Elevation Dam D Minimum Elevation for Standart Year Minimum Elevation 1 in 50 Dry Year
Minimum Elevation 1 in 100 Dry Year Standart conditions without Riparian Release
Under 100 year dry conditions, the pond trend is full dry-up
Projection 2006
Figure 5: Dam D Water Elevation Envelopes
Operational Level (Spillway Invert)
4,230
4,235
4,240
4,245
4,250
4,255
4,260
01/01
/2006
15/01
/2006
29/01
/2006
12/02
/2006
26/02
/2006
12/03
/2006
26/03
/2006
09/04
/2006
23/04
/2006
07/05
/2006
21/05
/2006
04/06
/2006
18/06
/2006
02/07
/2006
16/07
/2006
30/07
/2006
13/08
/2006
27/08
/2006
10/09
/2006
24/09
/2006
08/10
/2006
22/10
/2006
05/11
/2006
19/11
/2006
03/12
/2006
17/12
/2006
31/12
/2006
Elev
atio
n (m
asl)
0%
20%
40%
60%
80%
100%
Perc
enta
ge o
f Tot
al V
olum
e
100 Year Dry Conditions Max. Oscilation Standart Conditions Max. Oscilation 100 Year Wet Conditions Max. Oscilation
Current Elevation Dam D Minimum Elevation for Standart Year Minimum Elevation 1 in 50 Dry Year
Minimum Elevation 1 in 100 Dry Year Standart conditions without Riparian Release
Under 100 year dry conditions, the pond trend is full dry-up
Projection 2006
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