CLOSURE OF THE KINROSS DELAMAR MINE Steve Smith – Environmental Manager – Reclamation Operations (ROBU)
OPERATIONS MAP RUSSIA
NORTH AMERICA
Dvoinoye
Kupol
Fort Knox
Kettle River – Buckhorn Round Mountain
Toronto
WEST AFRICA Tasiast
Chirano
Lobo-Marte La Coipa
Paracatu
Maricunga Cerro Casale
SOUTH AMERICA
Operations Development Projects Head Office
2 kinross.com
DELAMAR MINE LOCATION
3 kinross.com
DELAMAR SITE HISTORY ● Historic Mining District 1863 to 1914 ● Ownership 1977-1993 – Earth Resources and NERCO ● 1993 – Kinross purchase NERCO property from Kennecott ● Kinross production 1993-1998 ● Care & Maintenance 1999-2002; Closure began in 2003
4 kinross.com
SITE CONDITIONS AT SHUT-DOWN ● Prolonged low metal prices forced shut-down and subsequent closure ● Record high precipitation during shut-down period ● ARD conditions at waste rock facilities and open pits ● Tailings pond also used for ARD storage
5 kinross.com
PREPARATIONS FOR FINAL RECLAMATION AND CLOSURE ● Lead regulatory agencies are the Idaho Dept. of Lands (IDL) and US BLM ● Supporting agencies include IDEQ, IDWR, and US EPA. ● In early 2002, Kinross established the Reclamation Operations Business Unit (ROBU), a separate unit within the company to manage reclamation and closure sites. ● Later in 2002, Policy and Technical Groups were formed with agency and company staff to update the existing Reclamation Plan into a comprehensive Closure Plan. ● Technical Group met monthly over a two-year period to review, modify and finalize the numerous engineering plans, as well as the overall Closure Plan. ● Approved reclamation projects were authorized to begin in 2003. ● By mid-2004, the guiding Closure Plan, Water Management Plan, engineering design plans, and other support documents had been extensively reviewed, modified, and approved for implementation over a 7-year schedule.
6 kinross.com
RECLAMATION DESIGN BASICS ● Engineered low-permeability covers on waste rock, open pits, tailings pond ● Site-wide water management; segregate impacted water from storm water ● De-water tailings by treatment and land application; construct dry cover Proposed Cover Designs Cover B selected
Topsoil K = 1.4e-3 cm/sec
Topsoil K = 1.4e-3 cm/sec
Compacted Clay K = 6.8e-7 cm/sec
Cover A
8"
8"
F.M Haul Road Fill 10" K = 2.0e-3 cm/sec
24"
Compacted Clay K = 6.8e-7 cm/sec
Cover B
24"
Topsoil / Rock Blend K = 1.4e-3 cm/sec
18"
Compacted Clay K = 6.8e-7 cm/sec
24"
Cover C
7 kinross.com
View from the North - 2006 Silver City
Stone Cabin Mine
DeLamar Office
Fretwell LAT
Adit 16 Jordan Creek
kinross.com
DeLamar Overview March 2012
8
WASTE ROCK #1 CLOSURE -- 2003-2004 ● Regraded to 3:1V, low-permeability cover including storm water conveyances
9 kinross.com
WASTE ROCK #1 CLOSURE -- 2003-2004 ● WD1 completed in 2004 ● Includes three buried seep collection systems to segregate storm water
10 kinross.com
INITIAL EFFECTS OF ENGINEERED COVER ●WASTE ROCK #1 -- MOST NOTEABLE ●Pre-reclamation (1999-2002) – ~600 to 800 af/yr ● 2005 – 377 af
● ● ● ● ●
2009 – 162 af 2010 – 166 af 2011 – 236 af (Above average snowpack, very wet spring; contingency pond) 2012 – 150 af 2013 - 125 af (est)
●Still see some climatic variation
11 kinross.com
MINE PIT CLOSURE – SOMMERCAMP PIT ● No static groundwater encountered ● Regrade to free-draining topography; backfill deeper, more reactive highwalls ● Construct low-permeability cover
12 kinross.com
MINE PIT CLOSURE -- SOMMERCAMP PIT ● Completed in 2006 ● Storm water free-drains to the north
13 kinross.com
MILL AREA DEMOLITION ● Removed building, refinery, mills, leach tanks, thickeners, AVR plant ● Due to good scrap metal prices, made a small profit ● Essentially everything was salvaged
14 kinross.com
TAILINGS POND CLOSURE -- 2003-2014 ● Very challenging circumstances; limited treat and discharge options ● 200-acre tailings surface ● Set aggressive schedule to retain agency support ● 4-layer cover; foundation, compacted clay, subsoil, soil; approx 8 ft total
15 kinross.com
TAILINGS POND CLOSURE -- 2006 ● Continued cover advance with declining water levels ● Foundation instability increasing ● Completed tailings embankment in 2006-2007
16 kinross.com
TAILINGS POND CLOSURE -- 2006 ● Stability concerns increased later in the construction season ● Began testing and changing over to smaller, LGP equipment ● October 2006 pond sonar survey; subsurface tailings waves Se ct io n
,2
Dit c
h
Te m po
ra ry
D 80 59 75 59
.5 % Be rm ,2 ,2 70 'l on g, 0
70
2.0%
A
ng, 0' lo
B
, 3,16
59
C
SOMMERCAMP REGAN PIT
Ditch
Se ct io n
B
,2 m er
5990
% .5
sion
Se ct io n
E
70
,0
iver r D te wa % -1.5
Se ct io n
5989 g on 'l
rm
Se ct io n
F
o St
Se ct io n
65 59
~26 acres
60 59
, e th lin ng pe ' le pi 7 33 2,
5 595
op dr 0' 14
pipeline 76 59
1
5976
p dro ne 0' 14 eli pip gth, len 7' ,10
0 595 5955' 5950' 5945' 5940'
contour contour contour contour
changes changes changes changes
DUMP #2
5945
6052
6020
Lime Addition System Building
Evap MCC Building
-1 .5
%
6014
17 kinross.com
TAILINGS POND CLOSURE -- 2007 ● Continue cover advancement ● Transition to LGP and geo-grid/geo-textile reinforced haul routes ● De-watering ACCELERATED due to reduced ARD flows to be stored ● Storm water diversion adjacent and on reclaimed areas
18 kinross.com
TAILINGS POND CLOSURE – LAND APP ● Land application best (only) reasonable option for de-watering ● Very closely controlled and monitoring by IDEQ ● Private land lease; very positive effect on landowner
19 kinross.com
TAILINGS POND CLOSURE -- 2008 ● Constructed water management pond ● Replaces lost water treatment/storage awaiting land application season ● Enlarged in 2012 to 350 acre-ft capacity
20 kinross.com
TAILINGS POND CLOSURE -- 2010 ● Continue cover advance with typical LGP D5 and 35 ton trucks ● Tailings surface essentially de-watered ● Increased management required for pore water and seeps
21 kinross.com
TAILINGS CLOSURE -- WATER ISSUES ● Increase in accumulated pore water drainage and seeps ● Increased water handling, tailings slimes handling ● Prepare to begin spillway excavation
22 kinross.com
TAILINGS POND CLOSURE -- 2011 ● Heavy snowpack and heavy spring rains ● Early season de-watering challenges ● Late season very successful
23 kinross.com
TAILINGS POND CLOSURE -- 2012 ● Normal spring weather patterns ● Previous year tailings drying and consolidation improve working conditions ● Successful construction season
24 kinross.com
TAILINGS POND CLOSURE -- 2013 ● Cover essentially complete, some localized areas and topsoil remaining ● Spillway excavation essentially complete and functional ● Variety of smaller projects in 2014 to finish earthworks
25 kinross.com
DELAMAR CLOSURE ●Key lesson learned (or confirmed) ●Need to focus on water inventory minimization during operation, especially as closure approaches. ●If not constrained by regulatory commitments or other requirements; then, more efficient to nearly complete tailings de-watering before cover construction.
26 kinross.com
DELAMAR CLOSURE – 1990’s
-- 2012
27 kinross.com
