INAPWATER TREATMENT WORKSHOP

August 8, 2009

Engineered Membrane Systems (EMS®) for ARD & other Hydrometallurgical Applications

By Larry A. LienDirector, Membrane TechnologyHW Process Technologies, Inc.

Why Membrane Technology?

The mining and metals refinery industry canbenefit from membrane technology:• Recovery of metals• Recovery of acids or caustic• Recovery of energy• Reduction of disposal costs• Meet Discharge limits currently not attainable

with traditional chemical precipitation

Membrane Classification

50 to 150 MWCO

150 to 500 MWCO

500, 1K, 2K & 3K MWCO

6K to 100K MWCO

.1 to 1 micron

Rejects all salts and acids 99+%

Hyperfiltration (HF)

Divalent salts rejected 99% but transmits salts or acids

Nanofiltration (NF)

Rejects Ferric Iron, Dyes & Small Colloids

Thin Film UF

Proteins Ultrafiltration (UF)

BacteriaMicrofiltration (MF)

Membrane-elements

Membrane Types• Polysulfone – 3 types• PVDF• PAN• Modified PAN• Cellulose Acetates – CA,

UF, NF, HF• Thin-film composite UF, NF,

HF of polyamides, sulfonated polysulfones, and proprietary polymers

Typical Spiral-wound Elements• Typical construction:

20 cm x 100 cm (30 m2)• High temperature – 140°C• High pH – 14• Low pH – 0• High viscosity – 300

Centipoise @ 90°C• High solids (soluble and

suspended)• Ultra-high pressures – 200

Bar

Acid reclamation concentrationwith HF or purification with NF

• Sulfuric• Nitric• Hydrochloric• Hydrofluoric

• Boric• Phosphoric• Acetic• Citric

Caustic high-pH environments with special HF and NF membranes

• Operated HF in high-pH cyanide solutions for4 years’ special construction to meet HWPT processing needs

• Recovery of 5% caustic solution with NF membrane with special construction for HWPT processes

Yanacocha

• Gold mining heap leach water balance issue at Yanacocha, Peru

• First HW Process Technologies Engineered Membrane Separation® (EMS®) system installed in 2003

• Currently, 2750 m3/hr of barren leach solution is treated and discharged safely into the environment

• Original elements installed in 2003 still operating effectively

Yanacocha process overview

HWPT EMS®

117.5 ppm CN WAD

Returned to Extraction

2200 m3/hr

1750 m3/hr afterChlorine Treatment

Discharged into Environment

Heap LeachCyanide Solution

Mining GoldExtraction

Merrill-Crowe

Water quality at Yanacocha

165.10.317.2Zinc

0.311.60.13.1Copper

89.80.6427.5Nitrate

17.110.095.19Nitrite

0.0020.0076<.00050.0025Mercury

0.5–1.01.5<.010.4Arsenic

0.2117.5<.0546.7CN WAD

6.0–9.09.78.010.1pH

Discharge Limitmg/L

Concentratemg/L

Permeatemg/L

Feedmg/L

Ionmg/L

HF of gold-cyanide complex concentration

HF Membrane

99% WADCyanide Removal

at pH >10.5

Water with trace amount of Cyanide

CN WADGold Cyanide Complex

Rejected 96.5+%

Au CN

Comments from Newmont’s Operators

• Meets water quality discharge standards (including nitrites and nitrates not regulated)

• Allows for future safe operation and expansion• Increased Gold and Silver recovery in membrane

concentrates (Au and Ag rejected at 96.5% rate by membranes –especially important during upset conditions)

• Cyanide recovery for re-use• Chlorine consumption reduced by 75% and overall

operating cost 70% less than conventional precipitation plant

• EASY TO OPERATE

NF of Copper-Cyanide complex concentration

Cu CN

Special NF Membrane

CN-1

CyanideTransmission 100%pH 10.5

Copper ComplexRejected 99.1+%

Au CN

Gold Cyanide Transmission 100%

Copper-Gold Fractionation Process

Heap

EMS®Copper

Recovery

EMS®GoldRecovery

To DischargeAu CN

Cu

Cu CN

Au CNCu CNPreg Soln

CN CN

Waihi Gold New Zealand Membrane Treatment Post Chemical Water Treatment Arsenic &

Selenium Removal Process

Tailings DamWaste Water Treatment Plant

Conventional Chemical Precipitation And Clarification

MultimediaFilter

1500 ppmNTU 5-5050 ppb As & 50 ppb Se

Rain Fall 2.5-3 Meters Annually

NTU< 1.0

EMS®

250 m3-h

Permeate to River DischargeTSDS <20 ppm As < 5 ppb & Se < 5 ppb

125 m3-h

125 m3-h

EMS®

212 m3-h

19 m3-h

19 m3-h

Water Quality Analysisfrom Waihi Gold

NA.50<.0040.053Molybdenum

20005589<21025Sulfate

NA2.1<.0040.37Cobalt

0.025.73<.000220.11Selenium

0.0020.0076<.00050.0015Mercury

< 0.0252.7<.0070.36Antimony

NA1500<1.1340Calcium

6.0–9.09.210.29.81pH

Discharge Limitmg/L

Concentratemg/L

Permeatemg/L

Feedmg/L

Ionmg/L

Use of special HF & NFMembrane-Elements

• NF Copper rejected & sulfuric acid transmission at Phelps-Dodge

• HF Copper and acid rejection at Phelps-Dodge

HF Membrane

Rejected

Transmission Water andTrace Amount of Acid

Feed1.23 g/l CuSO4

Sulfuric Acid10 g/l

100 g/l

CuSO4 andIron Rejexced

BothRejected

NF Membrane

Water & AcidTransmission

TransmissionOf all Acid and Water

Zero Liquid Discharge 17 years Operation (Freeport McMoran)

Phelps-Dodge Rod Mill El Paso, Tx

EMS®

HF 1000 psi 110°F

1-2% H2SO

4

1,230 ppm CU

20 m3/hr

EMS®

HF 21% Acid

500 ppm Cu1 m

3/hr

.01% Acid3 ppm Cu

Reuse as Rinse Water

EMS®

NF 110-12% Acid29,000 ppm Cu

10% Acid220 ppm Cu

.5 m3/hr

To Refinery - 2 m3/hr

To Copper Dissolving

35 ppm Cu.1% Acid

10-12% H2SO

4

8,000-9,000 ppm Cu

2 m3/hr

ZERO-DISCHARGESYSTEM

Cananea de MexicanCopper and Iron rejection

With special NF membrane-elements

BothRejected

NF Membrane

Transmission

CuSO4 andFeSO4

Water andSulfuric AcidTransmission

AMD Copper Reclamation Process

Nanofiltration System

Notes:

Date: October 3, 1996

Customer: Harrison Western Checked by: Larry Lien

Membrane Development Specialists / 1232-B Simpson Way / Escondido, CA 92029 / p: (619) 735-6210; f: (619) 489-6469

Overview of MCA

2000 GPM

1.6 g/L Cu40 g/L Fe

SulfuricAcid

Prefiltration1 micron

Feed0.8 g/L Cu20 g/L Fe

4000 GPM

30 x 22 x 15 Vessel Array

HeapCopper Rich

Drawn by: Nick Schmid

6 Elements per VesselEach Skid =402 Desal 5 Elements per Skid

800 psi1000 GPM

50% Recovery

Permeate

50 ppm Fe

2000 GPM<10 ppm Cu

Concentrate

AMD Copper Recovery Process

1,000 gpm

1,000 gpm

1,000 gpm

1,000 gpm

Concentrate 2,000 gpm1,400 ppm Copper40,000 ppm IronpH 0.9

Permeate 2,000 gpm <10 ppm Copper<50ppm Iron

From AMD Pit4,000 gpm

700 ppm Copper20,000 ppm Iron

pH 0.9

AMD Application at Cananea de Mexicana

• Recovery of copper directly from EMS® concentrate

• EMS® process paid for itself within 6 months via copper recovery

• Allowed mine to open new reserves that would previously have been flooded via an old 1890s mine shaft

Asarco Refinery WastewaterReclamation Project

• Legacy refinery with ground water pollution issues after 100 years of operation

• Precipitation system installed in 1985 – $1M capital and huge operating costs

• Membrane system installed in 1993 prior to precipitation – reduced volume to precipitation system from 6 m3/hr to 1 m3/hr

Comparison of Refinery Processes

• Copper refinery precipitation process prior to addition of membrane system

• Refinery layout with membrane system followed by precipitation

Surge Tank pH 4.04,000 - 10,000 ppm

Sodium CarbonateFerric Sulfate

Lime pH 9.8Sodium Sulfide

Clarification

Filter Press

Precipitate

Sludge Hauledfrom System

Difficult toDischarge and

Meet Specs

pH Adjust7.0

Precipitate

NF Membrane

NF Permeate80% Recovery

Media IMedia II

To SurfaceDischarge

Mixing &Clarifying

Tanks

Filter Press

Concentrateto Existing

Precipitation

VolumeReducedby 80%

Sludge HauledRe-refined

Liquid Returnedto Feed for NF

Capital and operating costs:Precipitation vs. Membrane-Media

$1.82$29.15Total Op cost per m3 treated

2.88 Kg19.24 KgTotal sludge generated per m3

$1.35$26.53Sludge disposal per m3

$.15 *$2.61 per m3Chemicals

$300K$1MCap Cost

Membrane-MediaPrecipitation

* Membrane cleaning and media regeneration

Final permeate water analyses

99.14% Extraction.58367.9Total Metals

.053.33Mn

.10.986Fe

.01.073Cu

.053.07Pb

.0133.5Zn

.0514.5Cd.08110.1As

Permeatemg/l

Feedmg/l

What makes EMS® plants unique?

• Every Application is Pilot Tested on Site• Special membranes and element construction for

High and Low pH Applications• Special system design for High and Low pH

Applications• Special operating procedures based on intimate

knowledge of the client’s process• Special cleaning procedures• 20 years of process membrane systems experience