Page 1
The Effective Hydrometallurgical
Treatment of Arsenic Bearing Copper
Ores and Concentrates
Eur Ing Dr. Corby G. Anderson QP CEng FIMMM FIChemE
Harrison Western Professor
Kroll Institute for Extractive Metallurgy
Colorado School of Mines
Golden, Colorado USA 80401
Page 2
CORNISH MAN ENGINE
MOUNTAIN MINE CIRCA 1850
Allihies, Beara Peninsula, Cork, Ireland
PERUMIN
30th Convencion Minera
Page 3
ANCESTORS - ANACONDA SMELTER
The Stack was built by the Alphons Custodis Chimney Construction Company of New York. At the time it was built,
May 5, 1919 it was the tallest masonry structure of any kind in the world at 585 feet.
PERUMIN
30th Convencion Minera
Page 4
Butte, Montana, USA
Granite Mountain Fire Memorial
June 8, 1917 – 168 Men Died
Dr. Corby G. Anderson
PERUMIN
30th Convencion Minera
Page 5
Big Creek, Idaho, USASunshine Fire - May 2, 1972 - 91 Men Died
PERUMIN
30th Convencion Minera
Page 6
Colorado School of Mines
• Est. 1874
• Golden, Colorado
• 21 majors
• 193 Faculty
• 4300 students
• “…have a unique mission in energy, mineral, and materials science and engineering…”
PERUMIN
30th Convencion Minera
Page 7
Department of Metallurgical & Materials
Engineering - MME
• 20 full time faculty members
• 5 Centers and Institutes:
–– Kroll Institute for Extractive MetallurgyKroll Institute for Extractive Metallurgy– Colorado Center for Advanced Ceramics
– Advanced Steel Processing & Products Res. Ctr.
– Center for Welding, Joining & Coating Research– Center for Welding, Joining & Coating Research
– Advanced Coatings & Surface Engineering Res. Ctr.
• Degrees:– PhD, MS, ME & BS in Metallurgical & Materials Engineering
– PhD & MS in Materials Science
– PhD & MS in Nuclear Engineering
• Students:– Graduate level: 120
– Undergraduate level: 50 per year
PERUMIN
30th Convencion Minera
Page 8
KIEM KIEM -- Kroll Institute for Extractive Metallurgy &CCRR 33 -- Center for Resource Recovery & RecyclingCenter for Resource Recovery & Recycling
Patrick R. Taylor Gerard P. Martins Brajendra Mishra Corby G. Anderson D. Erik Spiller Paul B. Queneau
Director, KIEM
G.S. Ansell
Distinguished
Professor of
Chemical
Metallurgy
EXPERTISE
�Mineral Processing
�Extractive Metallurgy
�Recycling
�Waste Treatment &
Minimization
�Thermal Plasma
Processing of Materials
�Thermal Plasma
Processing of Wastes
Professor of
Metallurgical and
Materials Engineering
EXPERTISE
�Process and
extraction metallurgy
�Engineered ceramic
and metal powders
�Electrochemical
systems
�Corrosion
�Transport phenomena
�Reactor Design &
kinetics
Director, CR3
Associate Director
KIEM, Professor of
Metallurgical and
Materials Engineering
EXPERTISE
�Pyrometallurgy
�Electrochemistry
�Materials synthesis
�Waste Processing
�Recycling
�Molten Salt
Processing
�Oxidation
�Reactive &
radioactive metals
�Glove box processing
Harrison Western Professor
of Metallurgical and
Materials Engineering
EXPERTISE
�Extractive Metallurgy
�Mineral Processing
�Recycling
� Waste Treatment &
Minimization
Research Professor of
Metallurgical and
Materials Engineering
EXPERTISE
�Mineral Processing
�Comminution
�Physical separation
�Recycling
�Flotation
�Leaching
�Liquid-solid
separation
�Project management
Research Professor of
Metallurgical and
Materials
Engineering
EXPERTISE
�Extractive and
process metallurgy
�Pyrometallurgy
�Recycling
�Waste treatment
and minimization
PERUMIN
30th Convencion Minera
Page 9
KIEMKIEM
The Kroll Institute for Extractive Metallurgy The Kroll Institute for Extractive Metallurgy -- KIE MKIEMDepartment of Metallurgical and Materials Engineeri ngDepartment of Metallurgical and Materials Engineeri ngColorado School of MinesColorado School of Mineswww.mines.eduwww.mines.edu
Page 10
ARSENIC
PERUMIN
30th Convencion Minera
Page 11
ARSENIC
Name: Arsenic Symbol: As Atomic Number: 33 Atomic Mass: 74.9216 amuMelting Point: 817.0 °C (1090.15 K, 1502.6 °F) Boiling Point: 613.0 °C (886.15 K, 1135.4 °F) Boiling Point: 613.0 °C (886.15 K, 1135.4 °F) Number of Protons/Electrons: 33 Number of Neutrons: 42 Classification: MetalloidCrystal Structure: RhombohedralDensity @ 293 K: 5.72 g/cm3
Color: Gray
PERUMIN
30th Convencion Minera
Page 12
ARSENIC
PERUMIN
30th Convencion Minera
Page 13
ARSENIC
PERUMIN
30th Convencion Minera
Page 14
MERCURY
PERUMIN
30th Convencion Minera
Page 15
MERCURY
Name: Mercury
Symbol: Hg
Atomic Number: 80
Atomic Mass: 200.59 amu
Melting Point: -38.87 °C (234.28 K, -37.966 °F)
Boiling Point: 356.58 °C (629.73 K, 673.844 °F) Boiling Point: 356.58 °C (629.73 K, 673.844 °F)
Number of Protons/Electrons: 80
Number of Neutrons: 121
Classification: Transition Metal
Crystal Structure: Rhombohedral
Density @ 293 K: 13.456 g/cm3
Color: Silver
PERUMIN
30th Convencion Minera
Page 16
MERCURY
PERUMIN
30th Convencion Minera
Page 17
MERCURY
Aktashite Cu6Hg3As4S12
Cinnabar HgS
Clearcreekite Hg (CO3)(OH)• 2H2O
CorderoiteHg3S2(Cl,Br)2
Kadyrelite Hg H(Br,Cl)3O2
Livingstonite HgSb4S8
Moschellandsbergite Ag2Hg3
Mosesite Hg N(Cl,SO ,MoO ,CO )•(H O) Mosesite Hg2N(Cl,SO4,MoO4,CO3)•(H2O)
Myrickite Cinnibar in Quartz
RouthieriteTl(Cu,Ag)(Hg,Zn)2(As,Sb)2S6
Terlinguaite Hg2OCl
Tiemannite HgSe
Montroydite HgO
Calomel HgCl
PERUMIN
30th Convencion Minera
Page 18
ANTIMONY
PERUMIN
30th Convencion Minera
Page 19
ANTIMONY
Name: Antimony
Symbol: Sb
Atomic Number: 51
Atomic Mass: 121.76 amu
Melting Point: 630.0 °C (903.15 K, 1166.0 °F)
Boiling Point: 1750.0 °C (2023.15 K, 3182.0 °F)
Number of Protons/Electrons: 51
Number of Neutrons: 71 Number of Neutrons: 71
Classification: Metalloid
Crystal Structure: Rhombohedral
Density @ 293 K: 6.684 g/cm3
Color: bluish
PERUMIN
30th Convencion Minera
Page 20
ANTIMONY
PERUMIN
30th Convencion Minera
Page 21
ANTIMONY
PERUMIN
30th Convencion Minera
Page 22
Technical Routes of Treatment
Pressure Oxidation
Roasting
Selective Leaching of Impurities
PERUMIN
30th Convencion Minera
Page 23
Technical Routes of Treatment
Pressure Oxidation
Advantage: Proven technology.
Disadvantage: High costs and complex plant Disadvantage: High costs and complex plant design and operation.
PERUMIN
30th Convencion Minera
Page 24
Technical Routes of Treatment
Roasting
Advantage: Proven technology.
Disadvantage: Challenges in containment Disadvantage: Challenges in containment and fixation of impurities.
PERUMIN
30th Convencion Minera
Page 25
Technical Routes of Treatment
Selective Leaching of Impurities
Advantage: proven technology with moderate costs and control and fixation of contaminants.
Disadvantage: Established technology but not well known.
PERUMIN
30th Convencion Minera
Page 26
ANDERSON ENARGITE PROJECTS
Marca Punta - Peru
El Galeno - Peru
Caspiche – Chile
Chelopech - Bulgaria
Lepanto – Phillipines
Tampaken – PhillipinesTampaken – Phillipines
Frieda River - New Guinea
Golpu – New Guineau
Mt. Carlton – Australia
El Indio - Chile
PERUMIN
30th Convencion Minera
Page 27
Hydrometallurgical Processing of Gold
Bearing Copper Enargite Concentrates
Dr. Corby G. AndersonDr. Larry G. Twidwell
PERUMIN
30th Convencion Minera
Page 28
Alkaline Sulfide Leaching Copper Concentrate
Industrial Plants
ASLASL -- Sunshine Mining 1945 Sunshine Mining 1945 –– 20022002
11stst and Longest Operating Copper and Longest Operating Copper Concentrate Alkaline Sulfide Leach Concentrate Alkaline Sulfide Leach Concentrate Alkaline Sulfide Leach Concentrate Alkaline Sulfide Leach Plant.Plant.
Produced Produced SbSb metal and removed metal and removed Hg and As providing clean Cu Hg and As providing clean Cu smelter concentrate.smelter concentrate.
PERUMIN
30th Convencion Minera
Page 29
Nitrogen Species Catalyzed Leaching Copper
Concentrate Industrial Plants
NSCNSC -- Sunshine Mining 1984 Sunshine Mining 1984 ––19951995
11stst and Longest Operating and Longest Operating Copper Concentrate Pressure Copper Concentrate Pressure Leach Plant.Leach Plant.
Produced Ag and Cu.Produced Ag and Cu.
PERUMIN
30th Convencion Minera
Page 30
Nitrogen Species Catalyzed Leaching
Copper Concentrate Industrial Plants
Sunshine Mining 1984 Sunshine Mining 1984 –– 19951995
11stst and Longest Operating and Longest Operating 11 and Longest Operating and Longest Operating Copper Concentrate Pressure Copper Concentrate Pressure Leach Plant.Leach Plant.
PERUMIN
30th Convencion Minera
Page 31
Industrial Copper Pressure
Leach History
Anaconda Arbiter ProcessAnaconda Arbiter Process 19741974
SunshineSunshineMiningMining 19841984
Mt. GordonMt. Gordon 19981998Mt. GordonMt. Gordon 19981998
Phelps DodgePhelps Dodge 20032003
OxianaOxiana 20052005
KansanshiKansanshi 20052005PERUMIN
30th Convencion Minera
Page 32
Nitrogen Species Catalyzed
Metallurgical Uses
–– Dissolution of Yellow CakeDissolution of Yellow Cake
–– Dissolution of Spent Uranium Fuel ElementsDissolution of Spent Uranium Fuel Elements
–– Pickling Agent for Stainless SteelPickling Agent for Stainless Steel–– Pickling Agent for Stainless SteelPickling Agent for Stainless Steel
–– Uranium Concentrate LeachingUranium Concentrate Leaching
–– Leaching of Phosphate RockLeaching of Phosphate Rock
–– 1st Proposed 1909 for Metal Sulfide Oxidation1st Proposed 1909 for Metal Sulfide Oxidation
PERUMIN
30th Convencion Minera
Page 33
Nitrogen Species Catalyzed
Leaching Fundamentals
3 MeS (S)+ 2HNO3 (Aq)+ 3H2SO4 (Aq) ����
3 MeSO4 + 3So (S) + 2NO (G) + 4H2O
NaNO2 (Aq) + H+ ���� HNO2 (Aq) + Na+
HNO2 (Aq) + H+ ���� NO+ (Aq) + H2O
2MeS (S) + 4NO+(Aq) ���� 2Me+2
(Aq) + 2So + 4NO (G)
PERUMIN
30th Convencion Minera
Page 34
Nitrogen Species Catalyzed
Leaching Fundamentals
Relative Potentials of Hydrometallurgical Oxidizers.
E0hOxidant
Redox Equation (pH = 0, H2 ref.)
Fe+3 Fe+3 + e- ���� Fe+2 0.770 VFe+3 Fe+3 + e- ���� Fe+2 0.770 V
HNO3 NO3- + 4H+ +3e- ���� NO(g) + 2H2O 0.957 V
HNO2 NO2 - + 2H+ + e- ���� NO(g) + H2O 1.202 V
O2 (g) O2 + 4H+ + 4e- ����2H2O 1.230 V
Cl2 (g) Cl2 (g) + 2e - ���� 2 Cl- 1.358 V
NO+ NO+ + e- ���� NO(g) 1.450 V
PERUMIN
30th Convencion Minera
Page 35
Nitrogen Species Catalyzed
Leaching Fundamentals
2NO (G) + O2 (G) < --> 2NO2 (G)
2NO2 (G) <--> 2NO2 (Aq)2NO2 (G) <--> 2NO2 (Aq)
2NO2 (Aq) + 2NO (Aq) + 4H+ <--> 4NO+ (Aq) + 2H2O
PERUMIN
30th Convencion Minera
Page 36
2MeS (G) + 4H+ + O2 (G) ���� 2Me+2(Aq) + 2So + 2H2O
Nitrogen Species Catalyzed
Leaching Fundamentals
PERUMIN
30th Convencion Minera
Page 37
NSC Process Advantages
1.1. First and Only Long Term Industrial Pressure First and Only Long Term Industrial Pressure Leach Process for Copper ConcentratesLeach Process for Copper Concentrates
2.2. Faster Reaction RateFaster Reaction Rate3.3. Smaller Reaction Autoclave Volume RequiredSmaller Reaction Autoclave Volume Required4.4. Eh/ORP Very HighEh/ORP Very High5.5. No Exotic/Expensive Materials of ConstructionNo Exotic/Expensive Materials of Construction5.5. No Exotic/Expensive Materials of ConstructionNo Exotic/Expensive Materials of Construction6.6. No Titanium NeededNo Titanium Needed7.7. No Fire DangerNo Fire Danger8.8. No Oxygen Dip TubeNo Oxygen Dip Tube9.9. Low Autoclave Temperatures (125Low Autoclave Temperatures (125ooC or170C or170ooC)C)10.10. Low Pressures (620 Low Pressures (620 kPagkPag or 975 or 975 kPagkPag))
PERUMIN
30th Convencion Minera
Page 38
NSC Process Advantages
11.11. No Brick or Lead Autoclave LinersNo Brick or Lead Autoclave Liners12.12. Less and Simpler Autoclave MaintenanceLess and Simpler Autoclave Maintenance13.13. No Special Agitator System for ONo Special Agitator System for O22 Mass Transfer toMass Transfer to
SolutionSolution14.14. Easier Feed Pump, Choke and Flash System DesignEasier Feed Pump, Choke and Flash System Design
and Operation along with Direct Heat Exchange/Recovery and Operation along with Direct Heat Exchange/Recovery 15.15. Like Smelting, Au and Ag Recovery is ExcellentLike Smelting, Au and Ag Recovery is Excellent16.16. No Complex Chloride Chemistry or Corrosion toNo Complex Chloride Chemistry or Corrosion to16.16. No Complex Chloride Chemistry or Corrosion toNo Complex Chloride Chemistry or Corrosion to
Deal with.Deal with.17.17. No Major Economic or Environmental IssuesNo Major Economic or Environmental Issues
Because of Limited Nitrogen Species Use in ProcessBecause of Limited Nitrogen Species Use in Process18.18. Lower Capital and Operating CostsLower Capital and Operating Costs19.19. Simple, Industrially Proven BySimple, Industrially Proven By--Product Sulfur Handling Product Sulfur Handling
Results in Value Added Products or Regenerated Reagents.Results in Value Added Products or Regenerated Reagents.
PERUMIN
30th Convencion Minera
Page 39
Nitrogen Species Catalyzed
Current Applications-- Copper Copper EnargiteEnargite Concentrates : South AmericaConcentrates : South America
–– Molybdenum Disulfide/Rhenium Concentrates : Molybdenum Disulfide/Rhenium Concentrates : United StatesUnited States
–– Gold Pyrite Concentrates : ChinaGold Pyrite Concentrates : China
–– Gold Gold ArsenopyriteArsenopyrite Concentrates : AsiaConcentrates : Asia–– Gold Gold ArsenopyriteArsenopyrite Concentrates : AsiaConcentrates : Asia
–– Gold Pyritic Tailings : South AmericaGold Pyritic Tailings : South America
–– Silver Bearing Concentrates and Pyritic Ores : So uth Silver Bearing Concentrates and Pyritic Ores : Sout h AmericaAmerica
-- Copper, Zinc, Nickel, Cobalt PM’s Copper, Zinc, Nickel, Cobalt PM’s –– AustraliaAustralia
-- Cobalt, Copper, Gold Cobalt, Copper, Gold –– United States United States –– Detailed Detailed Design UnderwayDesign Underway
PERUMIN
30th Convencion Minera
Page 40
Partial Nitrogen Species
Catalyzed Oxidation of a
Copper Enargite Concentrate
Composition of Enargite Concentrate Tested
Cu, % Fe, % As, % Au, g/T Tot. S. % p80 %
19.7 24.3 5.4 4.3 34.3 25 micron19.7 24.3 5.4 4.3 34.3 25 micron
PERUMIN
30th Convencion Minera
Page 41
PERUMIN
30th Convencion Minera
Page 42
STAT EASE
This commercially licensed program based on
fundamentals of design of experimentation provides
highly efficient:
Two-level factorial screening studies so that the vital
factors which affect a process can be identified.factors which affect a process can be identified.
Response surface methods to find ideal process
settings and achieve optimal performance.
Mixture design techniques to discover optimal
outcomes.
PERUMIN
30th Convencion Minera
Page 43
STAT EASE
The ‘Google’ product of applied testing and optimization.
Industrial laboratory testing and optimization clients
want;
Maximum results
Short turnaround
Low cost
Usually they have minimal amounts of representative
samples.
PERUMIN
30th Convencion Minera
Page 44
DOE NSC MATRIX
TABLE 1. STAT EASE DESIGN EXPERT ¼ TEST MATRIX.
Std Run Grind Time Initial Acid Max. Temp. Leach Time
1 1 0 min 50 g/L 150 C 120 min
7 2 0 min 100 g/L 130 C 60 min
5 3 0 min 50 g/L 150 C 60 min
10 4 5 min 75 g/L 140 C 90 min10 4 5 min 75 g/L 140 C 90 min
3 5 0 min 100 g/L 130 C 120 min
4 6 10 min 100 g/L 150 C 60 min
6 7 10 min 50 g/L 130 C 120 min
2 8 10 min 50 g/L 130 C 60 min
8 9 10 min 100 g/L 150 C 120 min
9 10 5 min 75 g/L 140 C 90 min
PERUMIN
30th Convencion Minera
Page 45
NSC TEST CONDITIONS
TABLE 2. NSC ENARGITE PARTIAL OXIDATION
Nitrogen Species Catalyzed
Partial Oxidation Leach Conditions.
Grind Time = Table 1
Initial Free Sulfuric Acid = Table 1Initial Free Sulfuric Acid = Table 1
Reactor Working Pressure = 620 kPag
Slurry Solids Content = Table 1
Maximum Temperature = Table 1
Total Time = Table 1
Nitrogen Species Concentration = 2.0 g/L
PERUMIN
30th Convencion Minera
Page 46
NSC DOE TEST RESULTS
TABLE 3. NSC TESTING RESULTS
Std Run As Rec. Cu Rec Fe, Rec
1 1 38.21 % 38.96 % 80.57 %
7 2 18.34 % 26.56 % 84.15 %
5 3 27.75 % 30.03 % 80.34 %
10 4 48.44 % 53.81 % 78.55 %
3 5 11.38 % 19.18 % 58.29 % 3 5 11.38 % 19.18 % 58.29 %
4 6 29.73 % 74.39 % 1.07 %
6 7 65.63 % 68.80 % 69.92 %
2 8 58.99 % 86.92 % 32.17 %
8 9 53.30 % 55.97 % 65.92 %
9 10 48.44 % 53.81 % 78.55 %
PERUMIN
30th Convencion Minera
Page 47
NSC STAT EASE MODEL
Final Copper Equation in Terms of Actual Factors
Cu Recovery =
+62.98042
+4.2837 * Grind Time
-0.12732 * Solids
-0.28707 * Initial Acidity
-0.026375 * Temperature
+0.061833 * Leach Time+0.061833 * Leach Time
+2.13467E-003 * Solids * Initial Acidity
-2.76833E-003 * Solids * Leach Time
Std. Dev. 0.000 R-Squared 1.00
Mean 50.84 Adj R-Squared 1.00
PERUMIN
30th Convencion Minera
Page 48
NSC STAT EASE RESPONSE
DESIGN-EXPERT Plot
Cu RecoveryDesign Points
X = B: SolidsY = C: Initial Acidity
Actual FactorsA: Grind Time = 10.0D: Temperature = 130.0E: Leach Time = 60.0
Cu Recovery
C: Initial Acidity
62.5
81.3
100.0
76.0
72.8
B: Solids
C: Initial Acidity
50.0 62.5 75.0 87.5 100.0
25.0
43.8
62.5
81.0
PERUMIN
30th Convencion Minera
Page 49
NSC STAT EASE RESPONSE
DESIGN-EXPERT Plot
As RecoveryX = B: SolidsY = C: Initial Acidity
Actual FactorsA: Grind Time = 10.0D: Temperature = 140.0E: Leach Time = 60.0
As Recovery
C: Initial Acidity
81.3
100.0
43.955.0
51.0
48.7
B: Solids
C: Initial Acidity
50.0 62.5 75.0 87.5 100.0
25.0
43.8
62.5
34.6
39.3
43.955.0
PERUMIN
30th Convencion Minera
Page 50
NSC STAT EASE RESPONSES Oxidized, %
44
63
81
100
26.0
28.0
30.0
33.1
32.0
32.0
Initial
Acidity, g/L
Influence of initial acidity and solids content on sulfur oxidized
(Constants: Grind Time, 10 min; T 130 C; Leach Time, 60 min)
Solids, g/L
50 63 75 88 100
25
26.0
24.0
PERUMIN
30th Convencion Minera
Page 51
NSC STAT EASE RESPONSEAcid Generation, g/g concentrate
44
63
81
100
0.40
0.60
0.30
0.10
0.20
Initial
Acidity, g/L
Solids, g/L
50 63 75 88 100
25
44
0.05
Influence of initial acidity and solids content on acid generation
(Constants: Grind Time, 10 min; T 130 C; Leach Time, 60 min)
PERUMIN
30th Convencion Minera
Page 52
OPTIMIZED NSC
PARTIAL OXIDATION
Nitrogen Species Catalyzed
Partial Oxidation Leach Conditions.
Grind Time = 25 minutes
Initial Free Sulfuric Acid = 25 g/L
Reactor Working Pressure = 620 kPag
Slurry Solids Content = 50 g/LSlurry Solids Content = 50 g/L
Maximum Temperature = 130 C
Total Time = 60 minutes
Nitrogen Species Concentration = 2.0 g/L
Copper Recovery = 95.01 %
Iron Recovery = 78.46 %
Arsenic Recovery = 86.93 %
Acid Generation = 0.125 g/g Concentrate
% Sulfur Oxidized to Solution = 67.11
PERUMIN
30th Convencion Minera
Page 53
Leaching Cycles = 8
Grind Time = 40 minutes
Initial Free Sulfuric Acid = 25 g/L
Reactor Working Pressure = 620 kPag
Slurry Solids Content = 50 g/L
Maximum Temperature = 130 C
Total Leach Tine = 45 minutes
Nitrogen Species Concentration = 2.0 g/L
Particle Size = 80% passing 15 micron
OPTIMIZED LOCKED CYCLE NSC PARTIAL OXIDATION
Particle Size = 80% passing 15 micron
Copper Recovery = 97.8 %
Iron Recovery = 51.2 %
Arsenic Recovery = 72.1 %
Mass Reduction = 64.91 %
Acid Generation = 0.06 g/g Concentrate
% Sulfur Oxidized to Solution = 62.66 %
Oxygen Consumption = 0.891 g/g concentrate
PERUMIN
30th Convencion Minera
Page 54
ARSENIC REMOVAL AND FIXATION
Three methods for removing arsenic from solution
were investigated:
Elevated Ambient Temperature Formation of Scorodite
Autoclave Formation of ScoroditeAutoclave Formation of Scorodite
Ambient Temperature (25 C) Removal of Arsenic by
Ferrihydrite Formation and Adsorption
PERUMIN
30th Convencion Minera
Page 55
Scorodite was produced to be used as seed for subsequent experiments
by precipitation from one-liter of 0.3 M Ferric Nitrate, 25 g/L As(V)
solution at 160 C, 24 hours.
PERUMIN
30th Convencion Minera
Page 56
Autoclave Formation of Scorodite
Autoclave leach solution-1 was pH adjusted to 1.06 and
subjected to autoclave precipitation. The experimental test
conditions were: 1-liter of solution was placed in the autoclave.
20-g/L of scorodite seed was added, the temperature was
raised to 160 C, held for 5-hr. The results are presented in the raised to 160 C, held for 5-hr. The results are presented in the
next slide This approach was successful and may be a viable
option, i.e. the arsenic is effectively removed as scorodite, yet
little copper is lost to the solids.
PERUMIN
30th Convencion Minera
Page 57
Autoclave Formation of Scorodite
Solution pH Removed from Solution,% (final conc, mg/L)
As Cu
1.06 Head 0 (1760) 0 (7262)
1.11 97.9 (36.5) 1.9 (7127)1.11 97.9 (36.5) 1.9 (7127)
Final phase formed confirmed by XRD is scorodite.
PERUMIN
30th Convencion Minera
Page 58
Autoclave Formation of Scorodite
PERUMIN
30th Convencion Minera
Page 59
Ambient Temperature (25 C) Removal of
Arsenic by Ferrihydrite Formation and Adsorption
Solution pH Concentration, mg/L
As Fe Cu
0.7 (head) 2774.0 11720.0 8352.0
3.1 105.94 823.7 8681.43.1 105.94 823.7 8681.4
4.0 6.78 139.5 8151.2
4.5 <0.03 DL 52.0 5221.7
4.6 <0.03 DL 48.4 4396.4
5.0 <0.03 DL 44.0 2568.3
PERUMIN
30th Convencion Minera
Page 60
Removal by Ferrihydrite Adsorption
8000
10000
12000
[M],
mg/
L As
Ambient Temperature (25 C) Removal of
Arsenic by Ferrihydrite Formation and Adsorption
0
2000
4000
6000
0 1 2 3 4 5
pH
[M],
mg/
L As
Fe
Cu
PERUMIN
30th Convencion Minera
Page 61
NSC Partial Oxidation Enargite Flowsheet
Enargite Concentrate
H2SO4 NaNO2 O2
Solids to ASL Gold Recovery
BALL MILL
MIXING TANK
AUTOCLAVE
THICKENER
Split Thickener Overflow A
Split T
hickener Overflow
B
Solids to ASL Gold Recovery
Scorodite
Copper Cement
Ferrihydrite Precipitation
Copper Metal
AUTOCLAVE (for Scorodite)
FILTER PRESSFILTER
PRESS
FILTER PRESS
MIXER SETTLER TANKELECTROWINNING
CELL
CEMENTATION TANK
Copper Solution
Raffinate
Iron Metal
Split T
hickener Overflow
B
PERUMIN
30th Convencion Minera
Page 62
Cu, % Co, % Fe, % As, % Au, Total S,
Partial Nitrogen Species Catalyzed Pressure
Oxidation of a Cobaltite Chalcopyrite Concentrate
It is now proposed that the NSC pressure leach facility be used to treat a gold bearing
chalcopyrite and cobaltite concentrate. NSC concentrate leach testing has been
conducted at and the results were as follows.
Table 35.Composition of Concentrate Tested.
Cu, % Co, % Fe, % As, % Au, o/T
Total S, %
7.2 14.4 14.4 20.0 0.42 19.0
PERUMIN
30th Convencion Minera
Page 63
Operating Criteria Unit
Initial Free Sulphuric Acid 100 g/L
Reactor Working Pressure 620 kPag
Slurry Solids Content 100 g/L
Solids Size 80% -10 micron
Maximum Temperature 125°C
Nitrogen Species Catalyzed Partial Nitrogen Species Catalyzed Partial Nitrogen Species Catalyzed Partial Nitrogen Species Catalyzed Partial Oxidation Leach Conditions.Oxidation Leach Conditions.Oxidation Leach Conditions.Oxidation Leach Conditions.
Maximum Temperature 125°C
Nitrogen Species Concentration
2.0 g/L
Reaction Time 20 min
PERUMIN
30th Convencion Minera
Page 64
Cu,
%
Co, %
Fe, %
As %
Au, %
Mass Distribution of Nitrogen Species Catalyzed PressureMass Distribution of Nitrogen Species Catalyzed PressureMass Distribution of Nitrogen Species Catalyzed PressureMass Distribution of Nitrogen Species Catalyzed PressureLeaching of Cobaltite, Chalcopyrite Gold Concentrate.Leaching of Cobaltite, Chalcopyrite Gold Concentrate.Leaching of Cobaltite, Chalcopyrite Gold Concentrate.Leaching of Cobaltite, Chalcopyrite Gold Concentrate.
As seen the copper, cobalt and arsenic are solubilized and can be separated by conventional means with the sulphide oxidized to sulphurin a minimum amount of time.The gold is concentrated in the solids forrecovery by alkaline sulphide leaching solids.
% % % % %Solution 97.3 97.7 97.7 93.40.0 Solid 2.7 2.3 2.3 6.6 100.0
PERUMIN
30th Convencion Minera
Page 65
�Very selective lixiviant.
� Only As, Hg, Sb, Au and Sn have
significant solubilities.
Alkaline Sulfide Hydrometallurgy
Fundamentals
� Used industrially for Sb production in,
USA, USSR and China.
� Piloted for Sb and Au in Australia
PERUMIN
30th Convencion Minera
Page 66
Alkaline Sulfide Hydrometallurgy
Current Applications
---- Antimony and PM : Australia and EuropeAntimony and PM : Australia and Europe
–– Gold Pyrite Concentrates : ChinaGold Pyrite Concentrates : China
–– Gold Gold ArsenopyriteArsenopyrite Concentrates : AsiaConcentrates : Asia
–– Gold Pyritic Tailings : South AmericaGold Pyritic Tailings : South America
–– Copper Copper EnargiteEnargite : South America: South America
-- Copper Copper EnargiteEnargite : Asia/South Africa: Asia/South Africa
-- Copper Copper EnargiteEnargite : Asia./Australia: Asia./Australia
PERUMIN
30th Convencion Minera
Page 67
Alkaline Sulfide Hydrometallurgy - Sulfur Stability
Diagram.
Alkaline Sulfide Hydrometallurgy
Fundamentals
PERUMIN
30th Convencion Minera
Page 68
4S + 6OH- → 2S2- + S2O32- + H2O
(X-1)S + S2- → S2-X (where X = 2 to 5)
S 2- + 2(X-1)e- → xS2-
Alkaline Sulfide Hydrometallurgy
Fundamentals
SX2- + 2(X-1)e- → xS2-
S22- + 2e- → 2S2-
PERUMIN
30th Convencion Minera
Page 69
Alkaline Sulfide Hydrometallurgy
Fundamentals
Alkaline Sulfide Hydrometallurgy - Sulfur Meta Stable Diagram.
PERUMIN
30th Convencion Minera
Page 70
Alkaline Sulfide SolutionsAlkaline Sulfide Hydrometallurgy
Fundamentals
PERUMIN
30th Convencion Minera
Page 71
Na2S + As2S3 ���� 2NaAsS2
NaAsS2 + Na2S ���� Na3AsS3
Alkaline Sulfide Hydrometallurgy
Fundamentals
1.5 H2O + 2 Na2S + ½ As2O3 ����NaAsS2 + 3 NaOH
NaAsS2 + Na2S ���� Na3AsS3
PERUMIN
30th Convencion Minera
Page 72
Na3AsS4 + 2 O2 � Na3AsO4
2 O2 + Na2S � Na2SO4
3.5 O2 + 2NaOH + Na2S2 � 2Na2SO4 + H2O
8 O2 + 8NaOH + Na2S5 � 5Na2SO4 + 4H2O
2NaOH + 2 O + Na S O � 2Na SO + H O
Alkaline Sulfide Hydrometallurgy
Fundamentals
2NaOH + 2 O2 + Na2S2O3 � 2Na2SO4 + H2O
Arsenic is then precipitated by iron salt addition.
PERUMIN
30th Convencion Minera
Page 73
Alkaline Sulfide Waste Solution Treatment
• ~ 100% sulfide oxidation to sulfate
• Sodium sulfate crystals were precipitated from the treated
solution
• XRD scans confirmed Na2SO4
PERUMIN
30th Convencion Minera
Page 74
Sodium Sulfate (Na2SO4) and Gypsum (CaSO4)
As a Value Added By-product or for Sodium Hydroxide Regeneration
Alkaline Sulfide Waste Solution Treatment
Pulp and Paper Manufacture, Glass Industry, Ceramic Industry,
Detergents, Feed Supplements, Textile Dyes, Bleaching,
Photography
Sodium Sulfate
Photography
Soil Amendment for Agriculture or Cement Manufacture
Key Reagent Regenerations from Sodium Sulfate
Sulfuric Acid and Caustic Required for Process
Ammonium Sulfate Fertilizer can be Produced
Gypsum
PERUMIN
30th Convencion Minera
Page 75
2O2 + Na2S ���� Na2SO4
3.5O2 + 2NaOH + Na2S2 ���� 2Na2SO4 + H2O
8O2 + 8NaOH + Na2S5 ���� 5Na2SO4 + 4H2O
2NaOH + 2O2 + Na2S2O3 ���� 2Na2SO4 + H2O
Sodium Sulfate Production
Gypsum Production
Alkaline Sulfide Waste Solution Treatment
Na2SO4 + Ca(OH)2 ���� CaSO4 + NaOH
Key Reagent Regeneration Reactions from Sodium SulfateNa2SO4 + 2H2O ���� H2SO4 + 2NaOH
Or
2NH4OH + Na2SO4 ⇄⇄⇄⇄ 2NaOH + (NH4)2SO4
PERUMIN
30th Convencion Minera
Page 76
Alkaline Sulfide Waste Solution Treatment
Laboratory Electrodialysis Cell.
Key Reagent Regeneration Reactions from Sodium SulfateNa2SO4 + 2H2O ���� H2SO4 + 2NaOH
PERUMIN
30th Convencion Minera
Page 77
Gold lixiviation in the alkaline sulfide system
postulated to be the result of oxidation by
polysulfide and complexation as a sulfide .
Leaching may occur as;
Au + S AuS + e-
EPD 2003, March 2-6
Auo + S5-2 � AuS5
- + e-
Recovered by EW, cementation, chemical or
gaseous precipitation, IX, SX.
PERUMIN
30th Convencion Minera
Page 78
PERUMIN
30th Convencion Minera
Page 79
PERUMIN
30th Convencion Minera
Page 80
Alkaline Sulfide Gold Leaching Design of Experiments
PERUMIN
30th Convencion Minera
Page 81
Alkaline Sulfide Gold Leach Head Solution Assay.
Volume L Au Sb As Hg Sn
Alkaline Sulfide Gold Recovery
Adsorption
Volume L Au Sb As Hg Sn
0.5 88.7 ppm 21.0 g/L 5.31 g/L 274 ppm 1.84 g/L
PERUMIN
30th Convencion Minera
Page 82
Alkaline Sulfide Gold Leach Head Final Assay.
Volume L Au Sb As Hg Sn
Alkaline Sulfide Gold Recovery
Adsorption
0.5 1.5 ppm 21.1 g/L 5.21 g/L 274 ppm 1.89 g/L
PERUMIN
30th Convencion Minera
Page 83
Overall Gold Selectivity and Recovery.
Liquid Solid
Gold 1.7% 98.3%
Antimony 100.0% 0.0%
Alkaline Sulfide Gold Recovery
Adsorption
Antimony 100.0% 0.0%
Arsenic 100.0% 0.0%
Tin 100.0% 0.0%
Mercury 100.0% 0.0%
PERUMIN
30th Convencion Minera
Page 84
• Electrowinning
• Cementation
• Gaseous Precipitation
Alkaline Sulfide Gold Recovery
• Gaseous Precipitation
• Chemical Precipitation
• Solvent Extraction
• Ion Exchange
PERUMIN
30th Convencion Minera
Page 85
Electrowinning of Alkaline Sulfide
Leach Solution for Gold Recovery
PERUMIN
30th Convencion Minera
Page 86
ANALYSIS OF ENARGITE CONCENTRATE
Table 1. Concentrate Analysis.
Cu, % Fe, % As, % Au, o/T SiO2, % Ca, % Al, %
Alkaline Sulfide Hydrometallurgy
Application
2
15.83 16.59 0.87 0.10 20.11 1.21 3.56
X-ray diffraction analysis and MLA was undertaken to characterize the concentrate. The major phases present are Enargite, Cu3AsS4 and Quartz, SiO2.
PERUMIN
30th Convencion Minera
Page 87
Alkaline Sulfide Hydrometallurgy Enargite
Application
Alkaline Sulfide Leaching Conditions.
Slurry Solids Content = 400 g/L
Maximum Temperature = 103o C
NaOH Concentration = 25.0 g/LNaOH Concentration = 25.0 g/L
S-2 Concentration = 60.0 g/L
Total Time = 12 Hours
PERUMIN
30th Convencion Minera
Page 88
Alkaline Sulfide Hydrometallurgy Enargite
Application
Alkaline Sulfide Timed As Recoveries.
Time, Hr % As Leached
0 0.0
1 64.3
2 84.3
4 91.2
6 91.6
12 91.6
PERUMIN
30th Convencion Minera
Page 89
Alkaline Sulfide Hydrometallurgy Enargite
Application
Mass Distribution of Alkaline
Sulfide Leach Products
Cu , % As , % Au, %
Solution 0.0 91.6 32.6 Solution 0.0 91.6 32.6
Residue 100.0 8.4 67.4
Mass Reduction = 0.41 %
PERUMIN
30th Convencion Minera
Page 90
As, Au and Cu Leaching 400 g/L Solids, 103 C & 6 Ho urs.
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0P
erce
nt
0.0
10.0
20.0
30.0
10.0 20.0 30.0 40.0 50.0 60.0 70.0
S-2 Concentration (g/L)
SOLUTION Cu% SOLUTION As% SOLUTION Au% RESIDUE Cu% RESIDUE As% RESIDUE Au%
PERUMIN
30th Convencion Minera
Page 91
Alkaline Sulfide Hydrometallurgy Enargite
ApplicationLocked Cycle Leaching Results
Slurry Solids = 400 g/L
Leach Temperature = 100O C
NaOH = 25.0 g/L
S-2 = 60.0 g/L
Reaction Time = 4.0 Hrs
Locked Test Cycles = 7
Final Concentrate Weight Gain = 8.05 %Final Concentrate Weight Gain = 8.05 %
Reagent Consumption
NaOH = 17.65 Kg/Dry Tonne Concentrate
Na2S = 73.2 Kg/Tonne Dry Concentrate
Copper Recovered to Liquid = 0.00 %
Arsenic Recovered to Liquid = 93.72 %
Antimony Recovered to Liquid = 50.15 %
Silver Recovered to Liquid = 0.00 %
Gold Recovered to Liquid = 22.98 %
PERUMIN
30th Convencion Minera
Page 92
Alkaline Sulfide Hydrometallurgy Enargite
Application
Final Locked Cycle Leached Concentrate Analysis.
Cu, % Fe, % As, % Au, o/T SiO , % Ca, % Al, % Cu, % Fe, % As, % Au, o/T SiO2, % Ca, % Al, %
16.54 16.61 0.01 0.07 20.11 1.21 3.56
PERUMIN
30th Convencion Minera
Page 93
ALKALINE SULFIDE ENARGITE FLOWSHEET
Enargite Concentrate
ASL
Leaching
Thickener
Liquid
Recycle 95 %Solid
Drum Filter
Drum Filter
Solids to Smelter
Liquid
LiquidLiquid
SolidSolid
Solid
Tank
Autoclave
Gold
Recovery
Bleedstream 5 %
Tails Treatment
Tank
Iron Salts
Filter Press
PERUMIN
30th Convencion Minera
Page 94
THE INDUSTRIAL ALKALINE SULFIDE
HYDROMETALLURGICAL
TREATMENT OF MERCURY BEARING
ANTIMONY ORES AND CONCENTRATESANTIMONY ORES AND CONCENTRATES
Corby G. Anderson
PERUMIN
30th Convencion Minera
Page 95
Mercury is commonly found in association with antimony ores.
Cinnabar, HgS
Livingstonite, HgSb4S7
Tetrahedrite, Cu12Sb4S13
Stibnite, Sb SStibnite, Sb2S3
Found in Algeria, Mexico, USSR, Slovakia, Tajikistan, China and North America.
PERUMIN
30th Convencion Minera
Page 96
Alkaline Sulfide
Hydrometallurgy Fundamentals
PERUMIN
30th Convencion Minera
Page 97
The alkaline sulfide system is a very selective
lixiviant for antimony, arsenic, tin, gold and
mercury in lieu of other metals .
PERUMIN
30th Convencion Minera
Page 98
Na2S + Sb2S3 � 2NaSbS2
NaSbS2 + Na2S � Na3SbS3
PERUMIN
30th Convencion Minera
Page 99
Na2S + HgS � + Na2HgS2
PERUMIN
30th Convencion Minera
Page 100
0
1
2
HgS
HgO
Hg2SO4
Hg(l)
HgSO4(a)
Hg2+
S
SO42-HSO4
-volts)
Eh-pH Diagram for Mercury in the Alkaline Sulfide System.
-2
-1
0
0 2 4 6 8 10 12 14
HgS
Hg(l)
HgS22-
HS-H2S(a) S2-
pH
Eh (v
PERUMIN
30th Convencion Minera
Page 101
Na2S + SnS2 � + Na2SnS3
3Na S + As S � 2Na AsS3Na2S + As2S3 � 2Na3AsS3
PERUMIN
30th Convencion Minera
Page 102
PERUMIN
30th Convencion Minera
Page 103
4So + 6NaOH � 2Na2S + Na2S2O3 + 3H2O
(X-1) So + Na S � Na S (where X= 2 to 5) (X-1) So + Na2S � Na2SX (where X= 2 to 5)
PERUMIN
30th Convencion Minera
Page 104
PERUMIN
30th Convencion Minera
Page 105
Gold lixiviation in the alkaline sulfide system
postulated to be the result of oxidation by
polysulfide and complexation as a sulfide .
Leaching may occur as;
Au + S AuS + e-Auo + S5-2 � AuS5
- + e-
Recovered by EW, cementation, chemical or
gaseous precipitation, IX, SX.
PERUMIN
30th Convencion Minera
Page 106
Na2SX + (X-1)Na3SbS3 � (X-1)Na3SbS4 + Na2S
PERUMIN
30th Convencion Minera
Page 107
Electrowinning of Antimony
The primary anode reactions are;
4OH- ���� 4e- + 2H2O + O2
S-2 ���� 2e- + SO
The primary cathode reaction is;
SbS3 -3 + 3e- ���� SbO + 3S-2
PERUMIN
30th Convencion Minera
Page 108
Sodium Hydroxy Antimonate Production
2H2O + 2NaOH + Na3SbS4 + 4O2 ���� NaSb(OH)6 + 2Na2S2O3
2Na2HgS2 + H2O + O2 ���� 2HgS + Na2S2O3 + 2NaOH
PERUMIN
30th Convencion Minera
Page 109
PERUMIN
30th Convencion Minera
Page 110
Applications to Antimony Ores
Slovakia
Tajikistan
Chile
Peru
Mexico
North America
Australia
Sweden ????
PERUMIN
30th Convencion Minera
Page 111
Roznava Tetrahedrite Concentrate.
Sb, %, As, % Hg, %, Cu, %, Fe, % Ag, ppm Au, ppm TS, %
17.3 1.85 0.55 26.1 12.4 6,400 2.0 22.0
PERUMIN
30th Convencion Minera
Page 112
Alkaline Sulfide Leach Testing Conditions.
Leach Time = 12 Hr.
Roznava Concentrate = 100 g/L
Leach Temperature = 105O C
Sulfur Addition = 20 g/L
Sodium Hydroxide = 35 g/L
Sb Leached = 95.0 % As Leached = 60.0 %
Hg Leached =95.0 % Au Leached = 20.0 %
Cu Leached = 0.0 % Ag Leached = 0.0 %
PERUMIN
30th Convencion Minera
Page 113
Roznava Concentrate After Alkaline Sulfide Leaching.
Sb, %, As, % Hg, %, Cu, %, Fe, % Ag, ppm Au, ppm TS, %
0.87 0.74 0.03 26.1 12.4 6,400 1.6 22.0
PERUMIN
30th Convencion Minera
Page 114
Proposed Slovakian Plant Technology.
Alkaline sulfide leaching.
Solution purification by selective crystallization.
Mercury removal along with waste antimonate production.
Mercury selectively leached, stabilized, encapsulated and stored.
Alkaline sulfide lixiviated gold recovered by IX.
PERUMIN
30th Convencion Minera
Page 115
Slovakian Alkaline Sulfide Hydrometallurgical Economics.
There was some existing infrastructure.
Local costs for reagents, manpower and utilities were used.
Mercury is separated, stabilized and locally stored.
The plant produces 1,000 tons of high grade antimony per year by
electrowinning from Roznava mercury bearing tetrahedriteelectrowinning from Roznava mercury bearing tetrahedrite
concentrates.
The capital costs include installed equipment, piping, instrumentation
and engineering.
Copper concentrates suitable for smelter treatment will be produced.
PERUMIN
30th Convencion Minera
Page 116
Slovakian Alkaline Sulfide Hydrometallurgical Economics.
Estimated Unit Operating Costs.
Sulfur = $ 0.025 USD/lb EW Sb produced
Caustic = $ 0.20 USD/lb EW Sb produced
Steam = $ 0.20 USD/lb EW Sb produced
Electricity = $ 0.20 USD/lb EW Sb produced
Oxygen = $ 0.10 USD/lb EW Sb produced
Waste treatment = $ 0.025 EW USD/lb Sb producedWaste treatment = $ 0.025 EW USD/lb Sb produced
Wages = $ 0.10 USD/lb EW Sb produced
Maintenance = $ 0.05 USD/lb EW Sb produced
Total Operating Cost = $ 0.90 USD /lb EW Sb produced
PERUMIN
30th Convencion Minera
Page 117
Slovakian Alkaline Sulfide Hydrometallurgical Economics.
Estimated Unit Capital Costs.
Leaching and Solid Liquid Separation = $ 3,500,000.00 USD
Solution Purification = $ 1,500,000.00 USD
Electrowinning = $ 2,500,000.00 USD
Waste Treatment = $ 1,000,000.00 USD
First Fills and Working Capital = $1,500,000.00 USDFirst Fills and Working Capital = $1,500,000.00 USD
Total Capital Cost = $ 10,000,000.00 USD
PERUMIN
30th Convencion Minera
Page 118
Alkaline Sulfide Recovery Of Gold Utilizing
Nitrogen Species Catalyzed Pressure
Leaching
Dr. Corby G. Anderson
PERUMIN
30th Convencion Minera
Page 119
Gold Concentrate Treated With Complete NSC Sulfide Oxidation
Gold = 35 g/T Iron = 25.0% Arsenic = 6.31% Total Sulfur = 24.0%
This Kazakh arsenopyrite concentrate also This Kazakh arsenopyrite concentrate also has high carbon leading to preg robbing.
PERUMIN
30th Convencion Minera
Page 120
Nitrogen Species Catalyzed Complete Sulfide Oxidation Leach Conditions.
Initial Free Sulfuric Acid = 20 g/LReactor Working Pressure = 975 kPag
.
Reactor Working Pressure = 975 kPagSlurry Solids Content = 100 g/LSolids Size = 80% minus 10 micronMaximum Temperature = 170o C Nitrogen Species Concentration = 2.0 g/LReaction Time = 45 minutes
PERUMIN
30th Convencion Minera
Page 121
CIL Gold Recovery From Complete NSC Sulfide Oxidation.
CIL Au recovery = 94.2%
PERUMIN
30th Convencion Minera
Page 122
Gold Concentrate Treated With Partial NSC Sulfide Oxidation
Gold = 35 g/T Iron = 25.0% Arsenic = 6.31% Total Sulfur = 24.0%Arsenic = 6.31% Total Sulfur = 24.0%
PERUMIN
30th Convencion Minera
Page 123
Nitrogen Species Catalyzed Partial Sulfide Oxidation Leach Conditions.
Initial Free Sulfuric Acid = 50 g/LReactor Working Pressure = 620 kPagReactor Working Pressure = 620 kPagSlurry Solids Content = 100 g/LSolids Size = 80% minus 10 micronMaximum Temperature = 125o C Nitrogen Species Concentration = 2.0 g/LReaction Time = 30 minutes
PERUMIN
30th Convencion Minera
Page 124
Alkaline Sulfide Recovery With Partial NSC Sulfide Oxidation.
Alkaline Sulfide Au recovery = 93.3%
No cyanide is used to avoid preg robbing !!
PERUMIN
30th Convencion Minera
Page 125
Conclusion
Hydrometallurgy is very effective in the treatment of complex copper concentrates which contain impurities such as arsenic, antimony and mercury.
PERUMIN
30th Convencion Minera
Page 126
Thank you for this opportunity !
I look forward to my next visit to Peru.
PERUMIN
30th Convencion Minera
Page 127
The Effective Hydrometallurgical
Treatment of Arsenic Bearing Copper
Ores and Concentrates
Eur Ing Dr. Corby G. Anderson QP CEng FIMMM FIChemE
Harrison Western Professor
Kroll Institute for Extractive Metallurgy
Colorado School of Mines
Golden, Colorado USA 80401