2011 mar kalgoorlie_ieaust_

Integrated Water Management in theMining Sector:

Overview and a case study

Chris Hertle | Global Leader - Water

Leah Sertorio | Senior Process Engineer

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Integrated Water Management for the Mining Sector

Presentation Overview

• Introduction to GHD

• Threats and Opportunities in mining sector

• Water consumption and Value

• Water management optimisation

• Integrate leading edge technology

• A case study


At a glance


Where are we?


GHD’s Strategy

Client-centred culture:

• Actively nurture & maintain industry networks

• Develop comprehensive understanding ofour clients’ businesses

• Cultivate long-term partnerships and

• Foster a collaborative environment forour people to work together to accomplishmore for our clients.

Purpose - harness the experience and capability of our global network of talented people- become the preferred partner of our clients.


Market SectorsGHD serves clients in the global markets of:

• Water

• Energy and Resources

• Environment

• Property and Buildings

• Transportation


Water in Mining - a love-hate relationship

Burra, Copper Mine, SA

Can’t dig with it …

…. can’t dig without it


Threats and Limitations

Too little water

- Less mineral processed

- No operation possible

- No community survival

Too much water

- Ore body is difficult to access

- Environmental discharge

- Loss of production – recentexamples are ERA and Qldcoal industry

Flooded coal mine near Dalby, Qld in Jan 2011

AUD5-9Billion in lost production

Qld Resource Council estimate


Threats and Limitations

Water quality

- Drinking

- Processing

- Environmental discharge

Community concern

- Impact on society’s water resources

- Impact on the environment

Rio Tinto Mine, Spain

CSM field development

Four Corners, ABC, Feb 2011


Financial savings

- Efficient water use

- Pumping & heating or cooling

- Treatment

- Monitoring/metering

Growth potential

- More ore extracted

- More ore able to be processed

Opportunities – Water is Money

Water outlets


Water business

- Treat and sell excess water

- Irrigate crops

- Stock drinking water

Corporate citizenship

- Relationship with Community

- Public image and approval

Business imperative

Opportunities – Water is an asset

RO Plant


Water Consumption in WA

WA uses 10% of Australia's water

Water Consumption by State

4361

5922

4993

141

1365

43456

1495

3351

4562

2991

154

1168

45648

1371

0

1000

2000

3000

4000

5000

6000

7000

QLD NSW VIC NT SA TAS ACT WA

State

Gig

alitr

es (G

L)

2004/052008/09


Water Consumption in WAWA Mining uses 19 % of WA water and 63 % of the water used in mining in Australia

WA Industry Water Consumption in 2008/09

24%

6%

19%

4%2%8%

13%

24%Agriculture

Forestry and FishingMining

ManufacturingElectricity and Gas

Water SupplyOther Industries

Household


$ Generated by Water used by Industry

The mining industry gets good value per L of Water used – and its improving!

Industry Gross Value Added per GL of Water Consumed

2

97166

552

672

4

226164

493

709

0

100

200

300

400

500

600

700

800A

gric

ultu

re

Min

ing

Man

ufac

turin

g

Ele

ctric

ityan

d G

as

Wat

er s

uppl

y,se

wer

age

and

drai

nage

all o

ther

indu

strie

s

Industry

$mill 2004/05

2008/09


Water Consumption by Industry…

Mineral industry

Coal

Aluminium

Bauxite

Alumina refining

Aluminium smelting

Copper

Gold

Nickel

Zinc

Water Consumption(L/t)

200

1200 - 1600

30

3 160

1 400

50,000

500 - 1000

200,000

7 900

Australia used 14100GL in 2008/9 – 510 GL (3%) was used in mining


So things are pretty good– how can we improve?


Simple Steps for Water Use Optimisation

Identify water quality and quantity needs and water sources

Assess and monitor water quality and meter water flows

Develop a water balance model

Look at opportunities for water redistribution

Assess the need for water treatment

Select the best treatment strategy


Identify Water UsageExtraction

Processing

Dust Suppression

Cooling and heating

Vehicle Wash down

Slurry Conveyance

People : Drinking/Shower

Truck washing facility, Cannington Coal Mine, Qld


Groundwater

Rainwater

Public water supply

Dams, reservoirs

Potable water

Reclaimed water

Identify Water Sources

Somewhere in Western Australia


Map Water Movements on Site

SITE

GroundwaterRainwater

River

DrinkingWater

Public WaterSupply

ReclaimedWater

DamsReservoirs

Supply

EnvironmentalDischarge

Irrigation

Supply to otherIndustries

Recycling

Tailingponds

Retentionponds

Evaporation

Domestic wastewater

DewateringRun-off water

Process waterMineral separation

Equipment washing

Acid Mine Drainage

Dust management

Cooling and Drilling

Slurry Conveyance

Usage

Trea

tmen

t Pro

cess

es


Assess Water Quality

Water origin Typical Characteristics

Groundwater Variable salinity, pH and heavy metals

Runoff water High suspended solids, low metal content

Mine dewatering High salinity, heavy metal

Acid Mine Drainage Very low pH, high metal content, sulfates

Process water High salinity, suspended solids, heavy metals,process chemicals

Rainwater Slightly acidic pH

Sewage Pathogens, high ammonia, phosphorus and organics


Water Usage Quality requirements

Process water Comply with process operational needs

Mineral separation Comply with process operational needs

Human consumption Drinking water quality

Dust suppression Comply with health and safety requirements

Equipment washing Comply with health and safety requirements

Discharged water Comply with the environmental discharge license

Cooling Towers Limited by the scaling potential, low suspended solids

Assess Water Quality Requirements

Don’t forget the monitoring and metering program !


To do that , one needs data

Develop Water and salt Balance

The SITEPotable Water

240 ML/yr

ProcessCooling ???

Raw Water

500 ML/yr

Sewer Pit Waste

Category 175 ML/yr

Category 2140 ML/yr

Treatement

Treatment

WWTP

Category 3Wetlands

???

Evaporation

???

Rainfall/Groundwater???


Water Pinching

Redistribution of Water- from one area of the site to another- from one site to another- “fit-for-purpose” water quality

Stormwater Collection- preserve rainwater quality

Reuse of Domestic Wastewater

Reuse of industrial wastewater


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The Ultimate in Un-SustainabilityMammoth Water Condenser, Coolgardie, 132,000 gpd - 100 t/d fuel!In 1896 the worlds largest desalination plant was built in Western Australia atCoolgardie

Water Reuse The Way Forward!!


Water Treatment TechnologiesPretreatment - Physical / Chemical

Thickening, clarification and filtration- gravity, centrifugal, belt thickening- floatation- media filtration

Antiscalents

Coagulation/Flocculation- alum and iron salts- synthetic polymers

Precipitation/crystallisation- alkaline processes,- sulfide

Underground flocculation system at CMT, Tas


Water Treatment TechnologiesBiological Systems

Anaerobic systems- Removal of organics- Sulfate reduction and removal- Sulfide production & ppt of metals

High Rate Anaerobic Treatment

Aerobic systems- Removal of organics- Sulfide oxidation- Sulfur production- Removal of N & P


Water Treatment TechnologiesPost treatment - Physical

Membrane technologies- Micro-filtration- Ultra-filtration- Nano-filtration- Reverse Osmosis- Electro Dialysis Reversal (EDR)

Ion exchange- Resins- Natural and modified zeolite clays

FiltrationSandMultimediaGranular activated carbon

Microfiltration at Fosters, Qld


Slurry Management

Maximise slurry density to allow tighter water recycling

Dense phase stacking where possible

Recovery of slurries from runoff ponds

Biological systems for minerals recovery


Tailings Management

All treatment technologies produce a WASTE

Volume of waste produced varies

Tailings dam disposal

Water and waste recycling ?

Caustic recovery

Water recovery

Minerals recovery

Red Mud Dam at QAL, Qld


Case Study – use of RecycledWater


Regulations and Guidelines Vary Dependingon Type of Reuse

Indirect potable reuse More Stringent Regulations

Agricultural Reuse on Food Crops

Unrestricted Recreational Reuse

Unrestricted Urban Irrigation Reuse

Restricted Urban Irrigation Reuse

Restricted Recreational Reuse

Industrial Reuse

Environmental Reuse

Agricultural Reuse on Non-food Crops Less Stringent Regulations


Remote Mining Communities

Refinery1%

Roxby Downs9%Mine

2%

Smelter21%

Hydromet18%

Concentrator49%

Olympic Dam, South Australia Olympic Dam Mine & Processing Plant

The Desalination Plant

Olympic Way to Roxby Township

Leinster, Western Australia

2 500 EP WWTPDomestic SewageEffluent Reuse for irrigation in

township – ovals, parks

Leinster Township

WWTP

Evap Ponds


National Water Reuse Guidelines

Guidelines for Sewerage Systems –Use of Reclaimed Water(ARMCANZ/ANZECC/NHMRC)January 2000

National Guidelines for WaterRecycling – Managing Health &Environmental Risks (NRMMC, EPHC &AHMC)November 2006

Australian Guidelines for WaterRecycling – Augmentation of DrinkingWater Supplies (NRMMC & EPHC),Draft, release for public commentJuly 2007


State Reuse GuidelinesWestern Australia:

—Draft Guidelines for the Use of Recycled Water in Western Australia (April 2009)Queensland:

—Queensland Guidelines for the Safe Use of Recycled Water (EPA 2004)—Queensland Water Recycling Guidelines (December 2005)

South Australia:—South Australian Reclaimed Water Guidelines (Treated Effluent), (EPA/DHS 1999)

New South Wales:—NSW Guidelines for urban and residential use of reclaimed water (NSWRWCC 1993)

Victoria:—Victorian Guidelines for Environmental Management: Use of Reclaimed Water (EPAVictoria 2002)—Guidelines for Environmental Management: Dual Pipe water Recycling Schemes –Health and Environmental Risk Management (Victorian EPA Publication No. 1015, October2005).

Tasmania:—Environmental Guidelines for the Use of Recycled Water in Tasmania (DPIWE 2002)

ACT:—Defer to National Guidelines


Water for What?

Treatment Costs Fit for Purpose Water Quality

Urban recreational with controlled access &preventative measures, eg. Golf courses.Agriculture – processed foods

CLOW

Non-human food crops eg.woodlots, flowers, instant turf

DEXTRALOW

Urban Irrigation with restricted accessduring irrigation-ovals, parks & gardensDairy cattleIndustrial washdown water

BMEDIUM

Urban Irrigation with unrestricted access -ovals, parks & gardensUrban non-potable eg. Toilet flushingAgriculture – human food crops.

AHIGH

UsesClass


“Class A” Applications- HIGH Exposure Risk

High Probability of Public Contact or exposure –unrestricted public access & application


Risk – Management preferred to AvoidanceA Risk Management approach to water recycling, based on quantitative risk

assessment and “Hazard And Critical Control Point Analysis (HACCP), ispreferred to a Risk Avoidance approach.

Both the updated/revised National & State: Western Australian Guidelinessupport this concept

Clear water reuse guidelines and risk management frameworks are essentialto provide project certainty for system operators and public confidence thatpublic health and environmental protection are adequate.

Guidelines not binding at present but will help to remove institutional,regulatory and financing constraints, resolve insurance issues and minimiselitigation risks.

Health Department of W.A. will require compliance of all recycling schemesto guidelines within 5 years of acceptance of treatment system


Risk Management ApproachTwelve element framework for the management of recycled water qualityand use

Application of preventative measures (barriers) commensurate with the levelof risk

Based on risk managementSTEP 1: Define tolerable riskSTEP 2: Assess riskSTEP 3: Calculation of health based targets (log reductions)STEP 4: Preventative measures (achieve log reductions)

Performance subject to monitoring at a frequency that enables timelyintervention

End product monitoring to verify that the management system as a whole isoperational


Risk Assessment Model

COMMUNICATION, CONSULTATION, ENGAGEMENT, REVIEW

1. Issue Identification

2. ExposureAssessment

3. HazardAssessment

4. RiskCharacterisation

5. Risk Management

ReviewReview


Log Reductions for Specified Uses

3.73.84.80.05Toilet flushing

4.84.95.90.5Irrigation ofFood crops

7.98.09.0700Drinking

4.9560.66UrbanIrrigation

ProtozoaBacteriaVirus(L/year)Log Reduction RequiredExposureWater use


Log Reductions in Process Barriers

0.5 – 1.51.0 – 3.00 - 2.0Secondary Treatment

0.5 – 3.00 – 1.00.5 – 3.0Tertiary Treatment – Media Filtration +coagulation

> 62.5 - >62.0 – 4.0Tertiary Treatment - Membrane filtration

0 – 1.52 - 61.0 – 3.0Chlorination

> 42 - >42.0 – 4.0UV Irradiation

0 – 1.00 – 0.50 – 0.1Primary Treatment

ProtozoaBacteriaVirusProcess Barriers

Log Reductions


Examples and Performance of PreventativeMeasures

4Subsurface Irrigation

0.5 log per dayImpoundment/with holding

1Spray drift control

Log ReductionsPreventative Measure

1Buffer Zone

2No public access when irrigating

2Drip Irrigation

5 - 6Cooking or Processing



Putting Recycled Water Risk in Perspective


Waste Water Treatment SystemMentioned ABOVE

Preliminary - Screening Removal

Primary - Solids RemovalGravity SedimentationFlotationCyclonic Systems

Secondary - Biological RemovalLagoon SystemsTrickling FiltersActivated Sludge (OxidationDitches & MBBRs)SBRsMBRs


Waste Water Treatment System

Tertiary - Water ReuseMedia FiltrationMembrane Filtration i.e. MF/UF &NF/ROBiological Nutrient Removal (BNR)Electrolysis, Electro-dialysis andEvaporationAmmonia Removal (Air Stripping)Chemical Phosphorus RemovalCarbon AdsorptionIon ExchangeAdvanced Oxidation

Disinfection - Water ReuseChlorinationChloramineUV Wastewater, MBR and RO effluent


Case Study – Leinster, W.A.WWTP system:– 2,500 EP Capacity– Domestic Sewage

Current WWTP:– Pasveer Channel System

incorporates solids removal;extended aeration; decanting;sludge disposal; disinfection

– Decant Water disposal viaEvaporation Ponds

WWTP Upgrade to achieve bettereffluent quality for water reuseirrigation in Leinster township &improve system reliability


Leinster, W.A – Building Community

Corporate citizenship- Relationship with Community- Public image and approval

Water is an asset- Treat and sell excess water- Water Reuse Irrigation –town ovals, golf course

Business imperative


ConclusionWater issues vary from one site to the other

Water management can be improved by:- Identifying water usages and water sources- Monitoring water quality and metering key water flows- Constructing and maintaining a water/salt balance- Looking at opportunities for water redistribution- Assessing the need for water treatment- Selecting the best treatment strategy and technology

Goro Nickel, New Caledonia


www.ghd.com

2011 mar kalgoorlie_ieaust_

Business

sell excess

integrated

mining sector

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