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