SlideShare una empresa de Scribd logo
1 de 30
SAL OR DESAL

SEAWATER SUPPLY OPTIONS
 FOR THE MINING INDUSTRY

  Raymond Philippe, Richard Dixon and
         Silvana Dal Pozzo
 Hatch Ingenieros y Consultores Ltda, Chile
Decision Seawater
            Saline - desalinated
• Is not (should not be):

   – CAPEX Saline = CAPEX desalinated – CAPEX desal plant +
     corrosion compensation

   – Trade-off based on SWOT analysis (qualitative)
      • Depending on the mining project, water supply may
        represent up to 10-30% of CAPEX of the overall project
      • Requieres engineering to get to a project feasibility estimate
Contents
• Experience use of seawater in mining
• Identification of differences salt vs.
  desalinated seawater
  – Chemical aspects
  – Conveyance
  – Aspects on the use of seawater in mining
    processes
• Conclusions
Characteristics
          Chilean Mining Project
•   Norte Chile (desert), water scarcity
•   High volumes (500 -10000 m3/h)
•   Project altitude (1500 – 4500 masl)
•   Distance to ocean (80-200 km)
•   Copper mining (Copper/moli, copper/gold)
•   Copper flotation
    – Greenfield
    – Technology conversion from oxides to sulphides processing
Experience seawater usage
• Desalinated seawater
  – Escondida, Chile                                                    2002-2011 Installed SWRO Capacity

                                                    5,000,000                                                                              1400
  – Cerro Lindo, Peru                               4,500,000
                                                                                                                              1242 MGD

                                                                                                                                           1200
                                                                                                                         1057 MGD
                                                    4,000,000

                                                    3,500,000                                                     898 MGD                  1000


• Potable water (SWRO)

                                 Capacity (M 3/d)
                                                    3,000,000                                             740 MGD
                                                                                                                                           800
                                                    2,500,000
                                                                                                     584 MGD
                                                                                                                                           600
                                                    2,000,000
                                                                                            454 MGD
                                                                                      418 MGD
                                                    1,500,000                                                                              400
                                                                            312 MGD
          Total Chilean mining                      1,000,000
                                                                       281 MGD

          Water consumption                          500,000
                                                                                                                                           200
                                                                65 MGD

                                                           0                                                                               0
                                                                2002    2003   2004    2005   2006    2007     2008   2009   2010   2011
                                                                                 Annual Installed SWRO Capacity
Experience seawater usage
• Salt water (seawater/ saline well water)
     •   Michilla, Chile
     •   Las Luces, Chile
     •   Mantos de la Luna, Chile
     •   BHP Nickel, Australia
     •   Texada Mines, Canada
     •   Batu Hijau, Indonesia

     • Esperanza, Chile (under construction)
Mantos de la Luna   Michilla




    Las Luces       Lipesed
Batu Hijau (Indonesia)                   Texada (Canada)


All existing direct salt seawater usage is in mining projects at short
distance and relatively low altitudes compared to the majority of the
actual mining projects in Chile

• Simple and economical conveyance systems
• Water conveyance costs do not require process optimization
(recirculation, thickened tailings)
Components
                  Seawater supply system

                                                     Minesite
                       Pretreatment
Altitude (masl)




                       Desal plant     Pumping
                                       Stations

                    Intake/
                    Outfall                               Electrical
                                                          Supply




                                      Distance (m)
Seawater Differences
       @15°C                     Saline       Desalinated
TDS                mg/l       36000       205
Cl                 mg/l       20175       119
SO4                mg/l       2590        4
BOD5               mg/l       variable    <5
Viscosity          m2/s.106   1.18431     1.13902
Specific Gravity   kg/l       1.026       1.000
Salt vs desalinated seawater
Possible impact differences in:
• Seawater intake (outfall)
• Pretreatment
• Desalination plant
• Conveyance system
• Mineral Processing
• Environment
• Financing
Salt vs desalinated seawater
Seawater intake and outfall
•   Intake volume capacity
•   Outfall from desalination plant
•   Permitting/Studies
•   Coastal space availability and concessions
Salt vs desalinated seawater
Desalination plant
• CAPEX
  – Mayor capital investment
  – For saline water: eventual requirement of smaller
    desal plant at minesite
• Operation costs
  – Desalination well understood, global experience
  – Specialized personnel, due to distance, difficult to
    integrate with minesite
Salt vs desalinated seawater
Pretreatment
  –   Desalination process requires pretreatment
  –   But salt water conveyance also requires pretreatment
  –   Chemicals handling/storage
  –   On site personnel
  –   Effluent and solids generation
  –   Organic matter
       • Removal instead of destruction
       • Red Tide events
Salt vs desalinated seawater
      Conveyance differences
• Gravity (Difference 3%)
• Viscosity (Difference 5 %)
• Corrosion
   – Materials selection pipes + pumps
   – Pipe thickness (steel,corrosion compensation)
      • Corrosion velocity (mpy, mm/y)
      • Oxidation ≠ Chloride pitting – choose correct testprocedures
   – Pipe protection (cathodic, liners, coating)
Conveyance -Genijev criterium
Pipe internal roughness as a function of time and fluid
εt = ε0 + a t                                                                     Genijev Roughness

                                                      9

   – Salt water <a> = 0.51                            8


   – Desalinated water <a> = 0.025                    7

                                                      6




                                     Roughness (mm)
                                                      5                                                               Desalinated

                                                      4                                                               Saline


                                                      3

                                                      2

                                                      1

                                                      0
                                                          0   1   2   3   4   5   6   7   8   9   10 11 12 13 14 15
                                                                                      Year




       Generally used Formula of Colebrook-White does
       not consider time or fluid dependency of pipe roughness
Salt vs desalinated seawater
            Conveyance
Should consider and compensate for
• Project life time
• Required availability of water supply system
• Difference in minimum pipe thickness requirements

• Difference in pressure drop between desalinated and
  salt water                                       L ρ
   – Piping design (include time dependency)        ΔP = λ          v2
   – Number and position of pumping stations                  D 2

  ** Avoid risk of underestimating pump capacities for salt water
Salt vs desalinated seawater
           Environment
• Environmental
  – Desalination plant outfall
  – Contamination
         – Leakages
         – Tailings pond infiltration
  – Emergency systems (containment ponds)
• Community issues
  – Desal plant location + size
  – Desalination plant outfall
Salt vs desalinated seawater
        Corrosion handling
Materials selection (base case: carbon steel)
• Desalination plant
• Conveyance system
• Concentrator

OPEX
• Antiscalant/Anticorrosion reagents
• Spare parts (2% CAPEX/yr)
Salt vs desalinated seawater
    Copper Mineral Processing
  Consideration: Most processes were developed based on industrial
  experience with “good” water quality, not salt water


• Sulphide processing (flotation), differences in
   –   Tailings (conventional and thickened)
   –   Molibdenum recovery
   –   Concentrate quality
   –   Carbonate/Gypsum scaling
   –   Corrosion
• Leaching
   – Oxides
   – Sulphides (bioleaching)
Salt water
          Tailings management
• There is global industrial experience in conventional
  tailings deposits using salt water, however, there is none
  using thickened tailings
• Thickened tailings with salt water behavior
   – Sedimentation velocity
      • Difference specific gravity
      • Capillary forces
   – Transport
      • Viscosity differences?
      • Salt precipitation (scaling)
Salt water
           Molibdenum recovery
• Poor recovery of molibdenum in selective
  flotation step
  – Requires good quality water
     • Requires small desalination plant to wash rougher
       concentrate (CAPEX/OPEX)
     • Additional installations
         – Washing              ]     (2-3 steps)
         – Thickening           ]
         – Eventually Filtering
     • Salt water requires higher dosification of reagents
         – Costs
         – Corrosion/scaling risk
Salt water
            used as Process Water
•   High concentrations of Cl y SO4
•   Salt water recirculation costs (OPEX)
•   Higher reagents consumption
•   Build-up of salts in process water
    – Evaporation losses
    – Desalination at site: reject to process water
        • Molibdenum
        • Potable water
        • Concentrate humidity
• Result: Process water may have even higher scaling and
  corrosion potential than fresh salt seawater
Salt water
      Reagents and consumables
• Extra process modifications required
   – pH control
   – Flotation reagents efficiency
   – Pyrite depression
   – Organic reagent degradation due to chloride contact
      • Flocculants
      • Flotation reagents
• Evaluate anticcorrosives (phosphates) interference in
  flotation processes
• Higher steel consumption in ball mills
Salt vs desalinated seawater
   Electrical energy requirements
• Seawater desalination
  – Reverse Osmosis (Chile) 4-5 kWh/m3
• Conveyance
  – Pipeline length
  – Project altitude
  – Pumping stations


  In general (new projects Chile):
  Energy consumption for conveyance >>> desalination
Salt vs desalinated seawater
                          Financing
Desalination plant financing
•   EPC as package within EPCM contract
•   BOO/BOT,…
•   US$/m3


Advantages
•   Take investment off of balance sheet
•   Lower OPEX?
Disadvantages
•   Control
•   Supply assurance
Execution Program
               Mining projects
• Conceptual Engineering
    – Definition water requirements
    – Trade-off salt vs desalinated water
•   (Pre)feasibility studies
•   EIA
•   Basic Engineering (acquisition major equipment)
•   Detailed Engineering and Construction
Execution program
       Seawater supply system
Indicative timing
• Preliminary Engineering             3-6 months
• Base line studies                   6-12 months
• EIA/Permits/Rights of way           6-18 months
• Acquisitions and delivery           10-14 months
• Construction                        6-12 months

• Mining vs water supply project:
   – Velocity/timing differences
   – Pressure on water project
   – Influence sal/desal definition
Analysis
        salt vs desalinated water
•   CAPEX                         (water supply + mine)
•   OPEX                          (water supply + mine)
•   Costs/Penalties/Opportunities (water supply + mine)
•   Risks                         (water supply + mine)
•   Environment and Community aspects
•   Minelife

    Based on cuantitative analysis and differences, mining
    company can base it’s decision
Conclusions
    Salt vs desalinated seawater
• Economic evaluation for both cases should consider not
  only differences in water supply systems but also
  associated costs to the overall mining project.

• Industry experience: In general not all relevant aspects
  for the alternatives evaluation are being considered

• Both alternatives should be developed to at least
  prefeasibility level (quantified) before decision is taken
   – Impact on CAPEX
   – Compatibilize execution programs

Más contenido relacionado

Destacado

Trends in mine water treatment March 2014
Trends in mine water treatment March 2014Trends in mine water treatment March 2014
Trends in mine water treatment March 2014Jakub Zielinski
 
08 Empirical Crystallisation
08 Empirical Crystallisation08 Empirical Crystallisation
08 Empirical CrystallisationAnthony Hardwicke
 
Raymond Philippe Enviromine09
Raymond Philippe Enviromine09Raymond Philippe Enviromine09
Raymond Philippe Enviromine09rphilippe
 
Mine Water Treatment SOQ
Mine Water Treatment SOQMine Water Treatment SOQ
Mine Water Treatment SOQJoe Woods
 
Experiencias en materia de transparencia y acceso a la iformación en Bahía de...
Experiencias en materia de transparencia y acceso a la iformación en Bahía de...Experiencias en materia de transparencia y acceso a la iformación en Bahía de...
Experiencias en materia de transparencia y acceso a la iformación en Bahía de...Proyecto Fronterizo de Educación Ambiental
 
Implementing Parature, by Microsoft Webinar Presented by InfoStrat
Implementing Parature, by Microsoft Webinar Presented by InfoStratImplementing Parature, by Microsoft Webinar Presented by InfoStrat
Implementing Parature, by Microsoft Webinar Presented by InfoStratJames Townsend
 
I Observatorio de siniestralidad laboral
I Observatorio de siniestralidad laboralI Observatorio de siniestralidad laboral
I Observatorio de siniestralidad laboralMarta Arnau Vergés
 
Mediacion laboral para emprendedores
Mediacion laboral para emprendedoresMediacion laboral para emprendedores
Mediacion laboral para emprendedoresBIS Facility Services
 
OIF Postcard Neuschwanstein_new
OIF Postcard Neuschwanstein_newOIF Postcard Neuschwanstein_new
OIF Postcard Neuschwanstein_newDorothee Luise Lee
 
First Class Flow Chart
First Class Flow ChartFirst Class Flow Chart
First Class Flow Chartdianmari
 
donkijote.org en la prensa digital 3
donkijote.org en la prensa digital 3donkijote.org en la prensa digital 3
donkijote.org en la prensa digital 3pankh
 
Tech Market Research Guide
Tech Market Research GuideTech Market Research Guide
Tech Market Research GuideBlaine Mathieu
 
Manual Modelos Cuantitativos
Manual Modelos CuantitativosManual Modelos Cuantitativos
Manual Modelos Cuantitativosfrairebobby
 
Top legal tips for publishing games in the EU
Top legal tips for publishing games in the EUTop legal tips for publishing games in the EU
Top legal tips for publishing games in the EUJas Purewal
 

Destacado (20)

Trends in mine water treatment March 2014
Trends in mine water treatment March 2014Trends in mine water treatment March 2014
Trends in mine water treatment March 2014
 
08 Empirical Crystallisation
08 Empirical Crystallisation08 Empirical Crystallisation
08 Empirical Crystallisation
 
Raymond Philippe Enviromine09
Raymond Philippe Enviromine09Raymond Philippe Enviromine09
Raymond Philippe Enviromine09
 
Mine Water Treatment SOQ
Mine Water Treatment SOQMine Water Treatment SOQ
Mine Water Treatment SOQ
 
Experiencias en materia de transparencia y acceso a la iformación en Bahía de...
Experiencias en materia de transparencia y acceso a la iformación en Bahía de...Experiencias en materia de transparencia y acceso a la iformación en Bahía de...
Experiencias en materia de transparencia y acceso a la iformación en Bahía de...
 
Implementing Parature, by Microsoft Webinar Presented by InfoStrat
Implementing Parature, by Microsoft Webinar Presented by InfoStratImplementing Parature, by Microsoft Webinar Presented by InfoStrat
Implementing Parature, by Microsoft Webinar Presented by InfoStrat
 
Current status of logistics in India
Current status of logistics in IndiaCurrent status of logistics in India
Current status of logistics in India
 
I Observatorio de siniestralidad laboral
I Observatorio de siniestralidad laboralI Observatorio de siniestralidad laboral
I Observatorio de siniestralidad laboral
 
Mediacion laboral para emprendedores
Mediacion laboral para emprendedoresMediacion laboral para emprendedores
Mediacion laboral para emprendedores
 
OIF Postcard Neuschwanstein_new
OIF Postcard Neuschwanstein_newOIF Postcard Neuschwanstein_new
OIF Postcard Neuschwanstein_new
 
First Class Flow Chart
First Class Flow ChartFirst Class Flow Chart
First Class Flow Chart
 
donkijote.org en la prensa digital 3
donkijote.org en la prensa digital 3donkijote.org en la prensa digital 3
donkijote.org en la prensa digital 3
 
Emiliano Duch Workshop
Emiliano Duch WorkshopEmiliano Duch Workshop
Emiliano Duch Workshop
 
Comprar un Anuncio
Comprar un AnuncioComprar un Anuncio
Comprar un Anuncio
 
Ansoáin ainhoa
Ansoáin ainhoaAnsoáin ainhoa
Ansoáin ainhoa
 
Tech Market Research Guide
Tech Market Research GuideTech Market Research Guide
Tech Market Research Guide
 
Cofipe
CofipeCofipe
Cofipe
 
Manual Modelos Cuantitativos
Manual Modelos CuantitativosManual Modelos Cuantitativos
Manual Modelos Cuantitativos
 
Anatomia cerebro y sistema visual
Anatomia cerebro y sistema visualAnatomia cerebro y sistema visual
Anatomia cerebro y sistema visual
 
Top legal tips for publishing games in the EU
Top legal tips for publishing games in the EUTop legal tips for publishing games in the EU
Top legal tips for publishing games in the EU
 

Similar a Wim 2010 Raymond Philippe Sal Or Desal

Magnesium weight saving option
Magnesium weight saving optionMagnesium weight saving option
Magnesium weight saving optiondguiaba
 
1450 peter vander
1450 peter vander1450 peter vander
1450 peter vanderSymposium
 
21st Century Coal Power Plants
21st Century Coal Power Plants21st Century Coal Power Plants
21st Century Coal Power PlantsJeffrey Phillips
 
Gold Resource Corporate Presentation
Gold Resource Corporate PresentationGold Resource Corporate Presentation
Gold Resource Corporate PresentationCompany Spotlight
 
Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)Andean American Gold
 
Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)Andean American Gold
 
Sea-water reverse osmosis (SWRO) - the basics
Sea-water reverse osmosis (SWRO) - the basicsSea-water reverse osmosis (SWRO) - the basics
Sea-water reverse osmosis (SWRO) - the basicsThe Texas Network, LLC
 
Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)
Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)
Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)Rare Earths / Rare Metals
 
Cortona Resources- Resources & Energy Symposium 2012
Cortona Resources- Resources & Energy Symposium 2012Cortona Resources- Resources & Energy Symposium 2012
Cortona Resources- Resources & Energy Symposium 2012Symposium
 
Png 492 pec final-presentation
Png 492  pec final-presentationPng 492  pec final-presentation
Png 492 pec final-presentationnas-psu
 
Png 492 pec final-presentation[1][1]
Png 492  pec final-presentation[1][1]Png 492  pec final-presentation[1][1]
Png 492 pec final-presentation[1][1]nas-psu
 

Similar a Wim 2010 Raymond Philippe Sal Or Desal (20)

Magnesium weight saving option
Magnesium weight saving optionMagnesium weight saving option
Magnesium weight saving option
 
1450 peter vander
1450 peter vander1450 peter vander
1450 peter vander
 
21st Century Coal Power Plants
21st Century Coal Power Plants21st Century Coal Power Plants
21st Century Coal Power Plants
 
Jacob Irving - CHA
Jacob Irving - CHAJacob Irving - CHA
Jacob Irving - CHA
 
Gold Resource Corporate Presentation
Gold Resource Corporate PresentationGold Resource Corporate Presentation
Gold Resource Corporate Presentation
 
Aa ggold presentation 10 4-10
Aa ggold presentation 10 4-10Aa ggold presentation 10 4-10
Aa ggold presentation 10 4-10
 
Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)
 
Aa ggold 13-10-10 pdf
Aa ggold 13-10-10 pdfAa ggold 13-10-10 pdf
Aa ggold 13-10-10 pdf
 
Impact Silver Corp. Presentation
Impact Silver Corp. PresentationImpact Silver Corp. Presentation
Impact Silver Corp. Presentation
 
Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)Andean American - Corporate Presentation (Sept. 2010)
Andean American - Corporate Presentation (Sept. 2010)
 
Grcpresentation
GrcpresentationGrcpresentation
Grcpresentation
 
Aa ggold 10 20-10
Aa ggold 10 20-10Aa ggold 10 20-10
Aa ggold 10 20-10
 
Deng - Permeability characterization and alteration due to reactive transport
Deng - Permeability characterization and  alteration due to reactive transportDeng - Permeability characterization and  alteration due to reactive transport
Deng - Permeability characterization and alteration due to reactive transport
 
2011 mar kalgoorlie_ieaust_
2011 mar kalgoorlie_ieaust_2011 mar kalgoorlie_ieaust_
2011 mar kalgoorlie_ieaust_
 
Sea-water reverse osmosis (SWRO) - the basics
Sea-water reverse osmosis (SWRO) - the basicsSea-water reverse osmosis (SWRO) - the basics
Sea-water reverse osmosis (SWRO) - the basics
 
VIZAG Steel
VIZAG SteelVIZAG Steel
VIZAG Steel
 
Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)
Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)
Commerce Resources Corp. (TSXv: CCE) Corporate Presentation (Jan 2011)
 
Cortona Resources- Resources & Energy Symposium 2012
Cortona Resources- Resources & Energy Symposium 2012Cortona Resources- Resources & Energy Symposium 2012
Cortona Resources- Resources & Energy Symposium 2012
 
Png 492 pec final-presentation
Png 492  pec final-presentationPng 492  pec final-presentation
Png 492 pec final-presentation
 
Png 492 pec final-presentation[1][1]
Png 492  pec final-presentation[1][1]Png 492  pec final-presentation[1][1]
Png 492 pec final-presentation[1][1]
 

Wim 2010 Raymond Philippe Sal Or Desal

  • 1. SAL OR DESAL SEAWATER SUPPLY OPTIONS FOR THE MINING INDUSTRY Raymond Philippe, Richard Dixon and Silvana Dal Pozzo Hatch Ingenieros y Consultores Ltda, Chile
  • 2. Decision Seawater Saline - desalinated • Is not (should not be): – CAPEX Saline = CAPEX desalinated – CAPEX desal plant + corrosion compensation – Trade-off based on SWOT analysis (qualitative) • Depending on the mining project, water supply may represent up to 10-30% of CAPEX of the overall project • Requieres engineering to get to a project feasibility estimate
  • 3. Contents • Experience use of seawater in mining • Identification of differences salt vs. desalinated seawater – Chemical aspects – Conveyance – Aspects on the use of seawater in mining processes • Conclusions
  • 4. Characteristics Chilean Mining Project • Norte Chile (desert), water scarcity • High volumes (500 -10000 m3/h) • Project altitude (1500 – 4500 masl) • Distance to ocean (80-200 km) • Copper mining (Copper/moli, copper/gold) • Copper flotation – Greenfield – Technology conversion from oxides to sulphides processing
  • 5. Experience seawater usage • Desalinated seawater – Escondida, Chile 2002-2011 Installed SWRO Capacity 5,000,000 1400 – Cerro Lindo, Peru 4,500,000 1242 MGD 1200 1057 MGD 4,000,000 3,500,000 898 MGD 1000 • Potable water (SWRO) Capacity (M 3/d) 3,000,000 740 MGD 800 2,500,000 584 MGD 600 2,000,000 454 MGD 418 MGD 1,500,000 400 312 MGD Total Chilean mining 1,000,000 281 MGD Water consumption 500,000 200 65 MGD 0 0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Annual Installed SWRO Capacity
  • 6. Experience seawater usage • Salt water (seawater/ saline well water) • Michilla, Chile • Las Luces, Chile • Mantos de la Luna, Chile • BHP Nickel, Australia • Texada Mines, Canada • Batu Hijau, Indonesia • Esperanza, Chile (under construction)
  • 7. Mantos de la Luna Michilla Las Luces Lipesed
  • 8. Batu Hijau (Indonesia) Texada (Canada) All existing direct salt seawater usage is in mining projects at short distance and relatively low altitudes compared to the majority of the actual mining projects in Chile • Simple and economical conveyance systems • Water conveyance costs do not require process optimization (recirculation, thickened tailings)
  • 9. Components Seawater supply system Minesite Pretreatment Altitude (masl) Desal plant Pumping Stations Intake/ Outfall Electrical Supply Distance (m)
  • 10. Seawater Differences @15°C Saline Desalinated TDS mg/l 36000 205 Cl mg/l 20175 119 SO4 mg/l 2590 4 BOD5 mg/l variable <5 Viscosity m2/s.106 1.18431 1.13902 Specific Gravity kg/l 1.026 1.000
  • 11. Salt vs desalinated seawater Possible impact differences in: • Seawater intake (outfall) • Pretreatment • Desalination plant • Conveyance system • Mineral Processing • Environment • Financing
  • 12. Salt vs desalinated seawater Seawater intake and outfall • Intake volume capacity • Outfall from desalination plant • Permitting/Studies • Coastal space availability and concessions
  • 13. Salt vs desalinated seawater Desalination plant • CAPEX – Mayor capital investment – For saline water: eventual requirement of smaller desal plant at minesite • Operation costs – Desalination well understood, global experience – Specialized personnel, due to distance, difficult to integrate with minesite
  • 14. Salt vs desalinated seawater Pretreatment – Desalination process requires pretreatment – But salt water conveyance also requires pretreatment – Chemicals handling/storage – On site personnel – Effluent and solids generation – Organic matter • Removal instead of destruction • Red Tide events
  • 15. Salt vs desalinated seawater Conveyance differences • Gravity (Difference 3%) • Viscosity (Difference 5 %) • Corrosion – Materials selection pipes + pumps – Pipe thickness (steel,corrosion compensation) • Corrosion velocity (mpy, mm/y) • Oxidation ≠ Chloride pitting – choose correct testprocedures – Pipe protection (cathodic, liners, coating)
  • 16. Conveyance -Genijev criterium Pipe internal roughness as a function of time and fluid εt = ε0 + a t Genijev Roughness 9 – Salt water <a> = 0.51 8 – Desalinated water <a> = 0.025 7 6 Roughness (mm) 5 Desalinated 4 Saline 3 2 1 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Year Generally used Formula of Colebrook-White does not consider time or fluid dependency of pipe roughness
  • 17. Salt vs desalinated seawater Conveyance Should consider and compensate for • Project life time • Required availability of water supply system • Difference in minimum pipe thickness requirements • Difference in pressure drop between desalinated and salt water L ρ – Piping design (include time dependency) ΔP = λ v2 – Number and position of pumping stations D 2 ** Avoid risk of underestimating pump capacities for salt water
  • 18. Salt vs desalinated seawater Environment • Environmental – Desalination plant outfall – Contamination – Leakages – Tailings pond infiltration – Emergency systems (containment ponds) • Community issues – Desal plant location + size – Desalination plant outfall
  • 19. Salt vs desalinated seawater Corrosion handling Materials selection (base case: carbon steel) • Desalination plant • Conveyance system • Concentrator OPEX • Antiscalant/Anticorrosion reagents • Spare parts (2% CAPEX/yr)
  • 20. Salt vs desalinated seawater Copper Mineral Processing Consideration: Most processes were developed based on industrial experience with “good” water quality, not salt water • Sulphide processing (flotation), differences in – Tailings (conventional and thickened) – Molibdenum recovery – Concentrate quality – Carbonate/Gypsum scaling – Corrosion • Leaching – Oxides – Sulphides (bioleaching)
  • 21. Salt water Tailings management • There is global industrial experience in conventional tailings deposits using salt water, however, there is none using thickened tailings • Thickened tailings with salt water behavior – Sedimentation velocity • Difference specific gravity • Capillary forces – Transport • Viscosity differences? • Salt precipitation (scaling)
  • 22. Salt water Molibdenum recovery • Poor recovery of molibdenum in selective flotation step – Requires good quality water • Requires small desalination plant to wash rougher concentrate (CAPEX/OPEX) • Additional installations – Washing ] (2-3 steps) – Thickening ] – Eventually Filtering • Salt water requires higher dosification of reagents – Costs – Corrosion/scaling risk
  • 23. Salt water used as Process Water • High concentrations of Cl y SO4 • Salt water recirculation costs (OPEX) • Higher reagents consumption • Build-up of salts in process water – Evaporation losses – Desalination at site: reject to process water • Molibdenum • Potable water • Concentrate humidity • Result: Process water may have even higher scaling and corrosion potential than fresh salt seawater
  • 24. Salt water Reagents and consumables • Extra process modifications required – pH control – Flotation reagents efficiency – Pyrite depression – Organic reagent degradation due to chloride contact • Flocculants • Flotation reagents • Evaluate anticcorrosives (phosphates) interference in flotation processes • Higher steel consumption in ball mills
  • 25. Salt vs desalinated seawater Electrical energy requirements • Seawater desalination – Reverse Osmosis (Chile) 4-5 kWh/m3 • Conveyance – Pipeline length – Project altitude – Pumping stations In general (new projects Chile): Energy consumption for conveyance >>> desalination
  • 26. Salt vs desalinated seawater Financing Desalination plant financing • EPC as package within EPCM contract • BOO/BOT,… • US$/m3 Advantages • Take investment off of balance sheet • Lower OPEX? Disadvantages • Control • Supply assurance
  • 27. Execution Program Mining projects • Conceptual Engineering – Definition water requirements – Trade-off salt vs desalinated water • (Pre)feasibility studies • EIA • Basic Engineering (acquisition major equipment) • Detailed Engineering and Construction
  • 28. Execution program Seawater supply system Indicative timing • Preliminary Engineering 3-6 months • Base line studies 6-12 months • EIA/Permits/Rights of way 6-18 months • Acquisitions and delivery 10-14 months • Construction 6-12 months • Mining vs water supply project: – Velocity/timing differences – Pressure on water project – Influence sal/desal definition
  • 29. Analysis salt vs desalinated water • CAPEX (water supply + mine) • OPEX (water supply + mine) • Costs/Penalties/Opportunities (water supply + mine) • Risks (water supply + mine) • Environment and Community aspects • Minelife Based on cuantitative analysis and differences, mining company can base it’s decision
  • 30. Conclusions Salt vs desalinated seawater • Economic evaluation for both cases should consider not only differences in water supply systems but also associated costs to the overall mining project. • Industry experience: In general not all relevant aspects for the alternatives evaluation are being considered • Both alternatives should be developed to at least prefeasibility level (quantified) before decision is taken – Impact on CAPEX – Compatibilize execution programs