TSX: LUN
OMX: LUMI
Mafalda Oliveira
Head of Department of Dams, Tailings, Waste Rock and Water
Tailings and Waste Rock as New Sources of Raw Materials
Bio Critical Metals Workshop, Coimbra , 6th June 2016
Lundin Mining - Main Operations
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Somincor and the Neves-Corvo mine
• Somincor is a subsidiary of Lundin Mining,
a diversified base metals mining company
with operations and projects in Portugal,
Sweden, Spain, Chile and the U.S.A.
• Neves Corvo Mine is located at Castro
Verde, Portugal, at about 220 km south of
Lisbon, and is the largest mine in Portugal
• The company was incorporated in July
1980, after the discovery of Neves-Corvo
deposits: the exploitation of copper ore
started in 1989, the exploitation of tin ore
started in 1990 and ended in 2005; the
exploitation of zinc ore started in 2006.
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Neves Corvo Mine - Characterisation
• Located in western edge of the
Iberian Pyrite Belt
• Underground high-grade Cu-(Sn)-Zn
mine
• Volcanogenic
deposit (VMS)
Massive
Sulphide
• The waste rock is composed of acid
volcanic rocks, black shales and
greywackes
which
contain
disseminated
sulphides
(mainly
pyrite)  reactive rock.
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Neves Corvo Mine – Mineral Deposits
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Hoisting & Processing
Tonnes
2012
2013
2014
2015
Production
3.037.364
3.503.130
3.658.277
3.501.246
Copper
2.507.054
2.534.816
2.539.599
2.501.024
530.310
968.314
1.118.678
1.000.222
Processed
3.054.814
3.499.214
3.605.849
3.556.252
Copper
2.511.938
2.525.334
2.503.354
2.542.355
542.877
973.880
1.102.494
1.013.897
1.242.123
740.789
429.168
148.989
Zinc
Zinc
Waste Rock Hoisted
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Mineral Processing Plants
Copper Plant
• Commissioned in 1988
• Conventional Grinding and Flotation
• Production in 2015
- 2.542.355 onnes treated with 2.72% Cu
- 231.912 tonnes Copper concentrates with 24.07% Cu
- Total of 55.831 tonnes of copper metal
Zinc Plant
Reconverted from the previous Tin Plant Total
Cost of 7.0M€
• Production started in July 2006
• Conventional Grinding and Flotation
• Production in 2015
- 1.013.847 tonnes treated with 8.01% Zn
- 138.347 tonnes Concentrated with 44.76% Zn
- Total of 61.921 tonnes Zinc metal
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SOMINCOR – Tailings Management Challenge
• Increase of tailings production
with time (low grade ores)
Since 2011:
• 49% increase tailings in Backfill
• 8% reduction tailings to TMF
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SOMINCOR – Tailings & Waste Rock Management
•
•
•
•
•
In 2015:
3.2 MTon of tailings were produced in flotation process
1.2 MTon were used in mine backfilling
2.0 MTon were stored at TMF
149 Kton of waste rock hoisted
•
•
•
•
At end of 2015:
39.7 MTon were stored at TMF, 10 MTon as Thickened Tailings (to date).
4.7 MTon of waste rock were stored in the TMF – co-deposition
3,9 Mton (1,8 Mm3) of waste rock temporarily stored at waste piles
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SOMINCOR – Tailings & Waste Rock Management
Important Aspects:
• The pyritic tailings produced in the copper and zinc plants have a high acidforming potential and therefore have been placed, since mine start up till
2010, sub-aqueously, in Cerro do Lobo TMF  implications for Tailings
Management (high associated costs).
• The two waste dumps, E1A and E1B, are for temporary storage of crushed
waste rock (0-200 mm) not used in backfilling. These dumps are not
permitted beyond the end of life of mine. The waste rock produces ARD 
Implications for Waste Management (high associated costs).
• Because Waste Rock and Tailings are not inert (produce ARD) they cannot
have any application in geotechnical or civil construction works, except in their
areas of deposition/storage.
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Location of Waste Rock Dumps
E2
E1
• The waste rock that isn’t used in the backfilling of the stopes is hoisted to
surface, after being crushed underground (0-200 mm), and is stored at the two
deposits: E1A and E1B
• These two dumps are temporary deposits and are not permitted at the end of
life of mine.
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Waste Rock Dumps - Structural Rehabilitation
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Waste Rock Dumps - Hydraulic Rehabilitation
• Acidic water is
collected and
pumped to the
TMF
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SOMINCOR – Tailings Circuit and TMF location
CONCENTRATE
Copper
Zinc
Lead
LEGEND
TAILINGS
THICKENED TAILINGS
PROCESS WTAER
Industrial Area
PLANTS
PASTE PLANT
CERRO DO LOBO TMF
(IRCL)
CERRO MINA RSERVOIR
(RCM)
Paste Plant
Cerro da Mina
Reservoir
Cerro do Lobo TMF
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SOMINCOR – Tailings & Waste Rock Management
Cerro do Lobo TMF
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SOMINCOR – Tailings Management
Cerro do Lobo TMF & subaqueous disposal
• The Cerro do Lobo TMF (IRCL) is a
large tailings pond, created by a
conventional rockfill dam, with
17x106 m3 of capacity for tailings
storage (total volume of 20x106
m3), a total crest length of
approximately 3.5 km and 42 m of
maximum height, and a footprint of
190 ha.
• The original embankment was
raised three times, using the
downstream method, in order to
cope with storage demand
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IRCL - Instrumentation at the Main Embankment
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SOMINCOR – Tailings & Waste Rock Management
• The capacity of the IRCL for sub-aqueous deposition would reach its limit in 2011,
although the mine has proven mineral resources until 2026, by mining a new ore body
• Conversion of sub-aqueous deposition (until 2010) to sub-aerial deposition using
thickened tailings, after 10 years of studies. Containment berms built with waste rock.
• Storage capacity of TMF increased by 100% (and from 2011 to 2026 based on current
LOM) with same footprint and therefore less environmental impact.
• Co-deposition of waste rock + tailings in the TMF => displacement of process water
• New reservoir for process water management – Cerro da Mina Reservoir
• Technology proposed as a BAT in the BREF revision in progress.
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Co-Disposal of Waste and Thickened Tailings
• The two DCT have capacity to treat the
total tailings production.
• From November 2010, until April 2015
thickened tailings (yellow) were stored
in the internal areas of TMF pond,
limited by waste rock berms (white),
leaving the external areas for industrial
water (blue) management, while the
new reservoir for industrial water
storage was not completed.
Characteristic values:
• 64% of solids
• 1,85 ton/m3
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IRCL – Vertical Expansion - plans & cross sections
Actual layout
Outlined final layout at closure
• Low flux cover
with
clean
raw materials
from a quarry
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Tailings Management - Subaerial Deposition
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Tailings Stack – Geotechnical & Geochemical
Monitoring
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Final remarks
• Due to the high costs associated with the proper management and
storage of tailings and waste rock, Somincor is producing the minimum
possible and reusing the maximum possible (wastes stored in crafted
structures).  current objective of EU.
• The costs associated with management of waste, following the best
practices, has a considerable weight in the company's budget.
• Any solution to value these waste, creating new applications for it, will
reduce the amount to be managed by the company and thus increase
the lifetime of existing facilities deferring / eliminated the need for
further expansion.
• Somincor has currently an investigation in progress with Universidade
do Minho and UTAD, for the alkaline activation and geopolymerization
of Waste Rock and Tailings.
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TSX: LUN
Thank You
OMX: LUMI