Mine Waste Management
Presented by Cam Scott,
SRK Consulting
Content of Mine Waste Management
Presentation
•
Overview of mine waste materials
•
Waste dumps and stockpiles
 Layout adjustments
 Foundation conditions
 Design section
 Construction methodology
•
PKCA
 Layout & storage capacity
 Foundation conditions
 Design section
 Construction methodology
•
Hazardous Materials
•
Highlights
Mine Waste Materials
Material
Life of Mine Tonnage
Overburden Soils
1.6 million
Waste Rock
12.8 million
Low Grade Ore
1.6 million
Recovery Rejects
0.1 million
Processed Coarse
Kimberlite (Coarse PK)
2.1 million
Processed Fine Kimberlite
(Fine PK)
0.4 million
Mine Waste Materials
JERICHO
EKATI
Life of Mine Tonnage
Tonnage in 1 Year (2002)
Overburden Soils
1.6 million
5.5 million
Waste Rock
12.8 million
41.2 million
Low Grade Ore
1.6 million
-
Recovery Rejects
0.1 million
-
Coarse PK
2.1 million
1.3 million
Fine PK
0.4 million
2.6 million
Material
Production Rates for Waste Materials
Overburden Soils
Waste Rock
Low Grade Ore
Recovery Rejects
Coarse PK
Fine PK
1
2
3
4
5
Years
6
7
8
9
10
Layout of Waste Dumps and
Stockpiles
Foundation Conditions at
Waste Dump/ Stockpile Sites
• Consist of either:
 Bedrock, or
 Bedrock with isolated soil
deposits
• All sites underlain by
permafrost
Typical Section through Waste
Dumps and Stockpiles
Dump/Stockpile Construction
(except Recovery Rejects Dump)
• To enhance physical stability:
 Organic soils in toe area to be stripped
 Material to be end-dumped in layers
 Overall slopes to be about 21 degrees
• To enhance geochemical stability
 A frozen layer to be maintained in the base of the
dumps/stockpiles
 For the low grade and coarse tailings stockpiles, a
layer of coarse, granitic waste rock will provide
separation with any organic soils
Recovery Rejects Dump Design and
Construction
• Organic soils to be stripped
• Compacted granitic waste rock to be
used to develop a uniform base
• Stockpile to overlie an HDPE (plastic)
liner bedded on either side with esker
sand
• Overall slopes of about 21 degrees
Layout of PKCA
PKCA Storage Capacity
No Ice Entrainment
El. 527: Top of Dams
Freeboard
El. 525: Top of Core
El. 523: Spillway
Water
1,410,000 m3
El. 517
Fine PK
≈ 380,000 m3
PKCA Storage Capacity
No Ice Entrainment
Extensive Ice Entrainment
El. 527: Top of Dams
Freeboard
El. 525: Top of Core
El. 523: Spillway
El. 527: Top of Dams
Freeboard
Water
El. 519
1,410,000 m3
El. 517
Fine PK
≈ 380,000 m3
El. 523: Spillway
1,013,000 m3
Water
Fine PK
El. 525: Top of Core
≈ 760,000 m3
Foundation Conditions at PKCA
Consist of:
• Bedrock, or soil overlying bedrock, on
the abutments
• Glacially deposited boulders/cobbles in
a till matrix of silt, sand and gravel in
the valley floor
• Underlain by a fault
• All dam sites are underlain by
permafrost that extends well into
bedrock
PK Containment (Dam Design)
•
Facility classification: low consequence
category
•
Containment provided by ice core dams
•
Dams at PKCA are 9 to 12 m high and the
settling pond dam is 6 m high
•
Allows for significant ice entrainment
•
Allows for water management and flood
storage
•
Design based on 2,475-year earthquake
Dam Design – Typical Section
Frozen core
PKCA Construction
• Conventional ice core dam
construction procedures using an
experienced contractor
• Mainly waste rock and esker sand
• Winter construction
Hazardous Materials
•
•
•
•
Petroleum
Hazardous Materials
Hazardous Wastes
Ammonium Nitrate Storage
Mine Waste Management Highlights
• Waste dumps and stockpiles
 Location of 3 dumps/stockpiles adjusted to
stay in one catchment
 Dump/stockpiles designed and constructed
to enhance physical and geochemical
stability
• PKCA
 Low consequence classification
 Adequate storage capacity
 Containment provided by the integration of
ice core dams with permafrost foundation
 Conventional construction methodology
• Hazardous Materials
 Handled using appropriate methods