Transcript Nichromet Cyanide-Free Gold Extraction Technology

Nichromet Extraction
Gold Technology
10/31/07
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Nichromet Cyanide-Free
Gold Extraction Technology
 A green alternative to
the classical cyanide approach
 Give access to ores
refractory to cyanidation
Nichromet Extraction Inc.
3700, Lac Noir Street
Thetford Mines (Qc)
418-423-7247
www.nichromet.com
10/31/07
 Less costly than the
classical processes without
environmental mortgage on
residues
 Can be implemented as
modular plant
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Vision
Develop an economic alternative to
classical cyanide process for gold
extraction, while keeping a
sustainable development approach
minimizing the impact on the
environment.
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Overview of the Process
Sulphides
Ores
Controlled
Oxidation
Sulfuric Acid
Acid
Leaching
Base Metals
Halogens
Treatment
Precious Metals
Inert Tailings
Nichromet Process Flowsheet
Copper
Removal
To Atm
From
Concentrtor
Oxidation
Pre-Treatment
Bag House
Concentrate
Copper
Extraction
Arsenic
Scrubber
SO2
Scrubber
Oxidation
Fluidized Bed
Gypsum
Gold Circuit
To Arsenic
Stabilization
Iron
Precipitation
Concentrated
Brine
Holding Tank
Chlorination
Reactor
Polished
Brine
Holding Tank
Hypohalides
Holding Tank
Deaeration
Tank
Reverse
Osmosis
Electrolysis
Cell
Ca(OH)2
Na2CO3
Hematite
Larox filter
Tailings
Iron
Precipitator
Calcium
Precipitator
Copper
Cementation
Pregnant
Brine
Holding
Tank
Carbon In
Column
Polishing
Filtration
Carbon to
Gold
Recovery
# DE DESSIN
Iron
Removal
TITRE
Sector 00 : General Flowsheet
REALISE PAR
Blister
Copper
David Lemieux
PAGE
1 SUR 1
DATE DE MODIFICATION
2013-02-12
Advantages Over Cyanide
 Faster Reaction Time
 Process time of few hours instead of few days
 Legal issues
 Cyanidation has been banned in many countries
and some States in USA (ex:Wisconsin)
 Extraction of silver and PGM if present
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Environmental Advantages




No cyanide
No tailings pond (elimination of spillage hazard)
No liquid effluent
Solids residues devoided of sulphides and base
metals
 No acidic lixiviate or contaminants from tailings site
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Characteristics of the
Nichromet Technology
Fast
• Leaching time of 2 hours instead of
2 days for cyanide
 Flexible
•Can handle base metals (bulk
flotation : higher efficiency)
•Can treat carbonaceous ore
•Can handle telluride
contamination
 Green
• Cyanide-free process
• Sulfide is recycled as sulfuric acid
• No waste water, no tailing pond
and no air pollutants
• Solid wastes : inert and stable,
even when using high arsenic ores
 Profitable
• Process cost ($/oz gold) similar to
cyanide
• Capital cost lower (10-15%) than
cyanide
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Successfully piloted at the ton scale
on a wide range of materials
Sources
Type
Grade
(g/T)
Barren
Solid (g/T)
Yield (%)
1: Canada
(Quebec)
Ore
2,58 g/T
0,07 g/T
97,5 %
2: Canada
(Quebec)
Ore
3,45 g/T
0,34 g/T
93,2 %
3: Canada
(Quebec)
Ore
13,9 g/T
0,79 g/T
95,4 %
4: Canada
(Ontario)*
Conc.
55,3 g/T
4,79 g/T
94,0 %
5 : Eastern
Europe*
Conc.
7,5 g/T
1,48 g/T
91,0 %
6: Canada
(Quebec)*
Conc.
53,5 g/T
3,56 g/T
94,1 %
*Flotation concentrates requiring pre-treatment by oxidation
Environmental Recognition
Grant of 700 k$ from Green Technologies
Demonstration Program of Quebec
Government in 2011-2012
Grant of 5 M$ from Sustainable
Technology Development Fund of
Federal Governement in 2013
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Somine Haïti Project vs
Nichromet Technology
 Current gold estimated resources (3,2 MT)
 Gold : 339 000 oz Au @ 3,27 g Au/T
 Copper : 28 Mlbs @ 0,4 %Cu
 Exploitation permit in force
 Mining plan
 Near surface resources (open pit potential, low operating cost)
 20 M$ investment done in exploration to date
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Great Potential for a
Nichromet plant in Haïti
Phase I
 Bring the top layer of the deposit into production
with a modular plant to process oxides
concentrate
 15 M$ investment for the modular plant only
 Potential of 25 000 oz Au/year
Phase II
 1000 TPD Mine and full scale processing plant
 Gold production rate of 35 000 oz Au/yr
 Investment for Nichromet processing plant of 35
M$
 Nichromet is currently conducting a demonstration
program for the application of its technology on the
Faille B deposit.
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Toward a Greener
Gold Industry
10/31/07