Canada

Diavik Mine

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Overview

Mine TypeOpen Pit & Underground
StatusActive
Commodities
  • Diamond
Mining Method
  • Truck & Shovel / Loader
  • Blast Hole Stoping
  • Sub-level Retreat
Backfill type
  • Cemented rockfill
Production Start2003
Mine Life2026
SnapshotThe Diavik Diamond Mine is Canada’s one of the largest diamond mines in terms of carat production. The Diavik Diamond Mine is known for its beautiful and sought-after white diamonds.

Rio Tinto announced building the largest solar power plant across Canada’s territories at Diavik Diamond Mine, featuring over 6,600 solar panels. It is expected to be fully operational in the first half of 2024.

Owners

SourceSource
CompanyInterestOwnership
Rio Tinto plc 100 % Indirect
Diavik mine is operated by Diavik Diamond Mines (2012) Inc. ("DDMI"). DDMI is a wholly-owned subsidiary of Rio Tinto PLC.

Post acquisition (18 November 2021), Rio Tinto now consolidate (100%) of the Diavik.

Deposit type

  • Kimberlite

Summary:

Diavik mine is Diamondiferous kimberlite deposit.

The mineral resource and reserve for the Diavik Diamond Mine consists of four diamondbearing kimberlite pipes located under water in Lac de Gras. The pipes are relatively small, each having surface expressions less than 200 m in diameter, but they are high in grade. The kimberlite pipes that underpin the present mining plan are named A154S, A154N and A418. The fourth pipe, A21, is fully permitted for mining and in November 2014 received corporate approvals to commence the stages of construction toward its development as an addition to the mine plan.

Diamonds are generally included as xenocrysts in kimberlite magma as it is formed and ascends through the upper mantle and crust. As the earth’s surface is approached, the kimberlite magma, which is rich in volatiles such as CO2, erupts explosively to form the characteristic root-shaped pipe structure. Abundant kimberlite is erupted as pyroclastic ejecta and falls both within and adjacent to the pipe. The pipe is filled with a combination of pyroclastic kimberlite, hypabyssal kimberlite, and country rock that slumped back into the pipe. At Lac de Gras, the tops of the pipes were removed by continental glaciation. The kimberlites are softer than the surrounding rocks so that depressions were formed after the glaciers retreated and filled with water to become lakes. When the pipes occur under larger lakes, such as Lac de Gras, the pipes typically lie beneath small depressions on the lake bottom.

Reserves at December 31, 2023

Diavik Ore Reserves are based on a nominal 1 millimetre lower cut-off size and a final re-crushing size of 6 millimetres.
CategoryTonnage CommodityGradeRecoverable carats
Proven 1.9 Mt Diamond 2.1 carats/t
Probable 1.3 Mt Diamond 2.3 carats/t
Proven & Probable 3.1 Mt Diamond 2.2 carats/t 7 M carats
Measured 1.5 Mt Diamond 2.4 carats/t
Indicated 1.2 Mt Diamond 2.7 carats/t
Measured & Indicated 2.7 Mt Diamond 2.5 carats/t
Inferred 0.3 Mt Diamond 2.1 carats/t
Total Resource 3 Mt Diamond 2.5 carats/t

Mining Methods

  • Truck & Shovel / Loader
  • Blast Hole Stoping
  • Sub-level Retreat

Summary:

Diavik mine is open pit and underground operations (blast-hole stoping and sub-level cave methods).

The Diavik Diamond Mine operates 24 hours per day, 365 days of the year. Crews at this remote site are resident on site while they work 12-hour shifts for 14 days, then rotate home for 14 days of rest. Four rotating crews cover 12-hour dayshifts, 12-hour nightshifts, on-site and offsite rotation.

Mine design, planning and scheduling is based on 5 m intervals.

Benches in the two completed pits and pit A21 are 10m high. Catchment berms in the end walls are spaced every three benches, and the "triple benches" 30m walls are pre-cut (pre-split) in one 30m pass. The A154-A418 combined open pit was designed to supply 1.5 million tonnes per annum (Mt/y) of kimberlite and exceeded this soon after commissioning in 2003, peaking at 2.4 Mt/y during 2006–2008 . The waste to ore ratio was relatively high, averaging 10 to 1 over the life of the pits. Total ore and waste production peaked at over 31 million tonnes per year and averaged 20–25 million tonnes per year for most of the time the two pits were shared. The A21 open pit will have a similarly high tailings to ore ratio and is expected to produce between 0.2 and 1.0+ Mtpa from 2018 to 2023, averaging around 0.6 Mt for a year.

Underground, blast-hole stopes are planned 25 m high and sub-level retreat stopes are also 25 m. Both mining methods take place simultaneously and multiple faces are in production from more than one level. Production ramp-up to the targeted steady-state output of 1.5–1.8 Mtpa ore took three years (2010–2012) as mine development in the granitic host rock pushed ahead to access additional ore faces. For 2013, Diavik’s first full year underground, the mine produced 1.9 Mt of ore and, with ore stockpiled from the open pit, processed 2.1 Mt. For 2014, 2.1 Mt of underground ore was mined and, with stockpiled ore, nearly 2.3 Mt was processed. Subsequent underground operating performance to the end of 2016 has been at similar levels.

For each of the pipes, pre-production stripping was carried out to remove lake-bottom sediments and glacial till (collectively referred to as overburden) that covered the bedrock and kimberlite pipe. Indistinguishable in the field and therefore mined as a single unit, the overburden was placed in a designated area so that it can be accessed and used in future for mine closure work.

Underground ore and waste is brought to surface at one of three portal entrances by underground haulage trucks and dumped on the ground in designated piles. The “portal muck” is then picked up by front-end loader and put onto surface haulage trucks (kept in service after the end of open pit mining) to be hauled either to the waste-rock dump (if waste rock) or to the ore processing plant.

Cemented rock-fill (“CRF”) is used as backfill underground. It is back-hauled into the mine (A154N only) from the nearby backfill plant by empty underground haulage trucks on their return trips.

Diavik’s fourth diamond pipe is known as A21. The ore body has been pivotal to extending the mine’s life and maximising the available mineral resource. While re-examining the feasibility of underground mining at A21, the Diavik team developed a plan that resulted in the approval of the first phase of a 2-phase expansion project. This created an extension of the mine’s life until the first quarter of 2026, ensuring sustained economic benefits to the region and our stakeholders.

The A418 underground kimberlite pipe was closed in the fourth quarter of 2022 and the A21 open pit kimberlite pipe was closed in early 2023.

Comminution

Crushers and Mills

TypeModelSizePowerQuantity
Jaw crusher 1
Cone crusher 1
High Pressure Grinding Rolls (HPGR) 1

Summary:

Crushing circuit consist of primary jaw crusher secondary cone crusher and high pressure grinding rolls.

Processing

  • Crush & Screen plant
  • Dense media separation
  • X-Ray sorting
  • Grease belt/table recovery

Summary:

Diamond ore processing uses no chemicals to separate diamonds from kimberlite. The gravitybased methods used rely on the relatively heavier weight of diamonds to separate them.

Since 2015, two streams have been added to the coarse diamond fraction in recovery. In October 2014, a grease table was added to the -12 +6mm fraction that scavenged the rejects from the primary free-fall machines. In October 2016, an additional x-ray machine was installed that allowed the scavenging of the -30mm +6mm fractions (the entire range) of the primary freefall x-ray rejects.

In the recovery section of the plant, the diamonds are separated from the waste minerals using x-rays that trigger the unique characteristic of diamonds to glow. This triggers photo-electric sensors that direct strategicallyplaced air blasts to blow the diamonds into collection receptacles. Waste material is re-crushed if it is greater than a specific size otherwise the material is considered rejects and is stockpiled with a possibility to be reprocessed in future. The recovered stones then move through a series of sorters to the bottom of the processing plant where — under stringent security surveillance — an authorized employee measures and records the weight of the stones and also removes any non-diamonds.

Total recovery of all stones larger than the screen aperture has been the goal as small diamonds are economically viable for Diavik to recover. Grease tables have been incorporated into the recovery plant to support this. The screen size was 1 mm initially but has since been reduced to 0.85 mm. Nominal screen size is reported as 1 mm to provide a small allowance for wear.

The recovered diamonds are stored in a secured vault while waiting to be flown to Yellowknife for further cleaning and sorting. The diamonds are separated and packaged by size, weighed and stored in a special suitcase for shipping. The diamonds are flown discreetly but under security escort to the Diavik Diamond Mine’s product splitting facility (“PSF”) in Yellowknife where it is “split” by size and value into respective shares for the two Diavik Joint Venture entities. The PSF’s quality management system is ISO 9001 certified.

Recoveries & Grades:

CommodityParameter201720162015
Diamond Head Grade, carats/t 333.2

Water Supply

Summary:

Process water is recirculated and reused with minimal makeup water taken from Lac de Gras. Drinking water is drawn from Lac de Gras and chlorinated. A state-of-the-art sewage treatment plant for treating domestic sewage serves the entire site. All wastewater, minewater, seepages and surface run-off are impounded and treated before release back to Lac de Gras.

Mining is made possible by building water retention dikes and dewatering portions of the lake so that
mining can take place within the dewatered area.

All mine water — dike and pit wall seepage, inflows from the kimberlite and country rock mass, surface run-off, precipitation — is collected via ditches, sumps, pumps and pipelines for storage and treatment in the wastewater treatment plant.

Production

There was a decrease in ore production in the fourth quarter of 2022 due to the closure of the A418 underground kimberlite pipe and the A21 open pit kimberlite pipe in early 2023, partially offset by improved underground A154N ore deliveries.
CommodityUnits202320222021202020192018201720162015
Diamond k carats 3,3404,6515,8436,2186,7197,2647,4866,6586,406
All production numbers are expressed as mineral.

Operational metrics

Metrics20232022202120202019201820162015
Tonnes processed 1,688 kt2,158 kt2,540 kt2,518 kt2,435 kt2,530 kt
Ore tonnes mined 2,214 kt1,984 kt

Production Costs

Commodity production costs have not been reported.

Financials

Units20232022
Capital expenditures M USD 66  48  
Revenue M USD 444  816  
Earnings M USD 26  151  
EBITDA M USD 44  330  

Heavy Mobile Equipment

Ref. Date: December 31, 2016

SourceSource
HME TypeModelSizeQuantityStatus
Backhoe Komatsu PC600LC 1 Required
Backhoe Caterpillar 430 2 Existing
Dozer (crawler) Caterpillar D10T 2 Required
Drill Cubex Orion 1 Existing
Drill DrillTech D75EX 3 Required
Drill (long hole) Atlas Copco Simba M6C 5 Existing
Excavator Hitachi EX1900 1 Required
Excavator Hitachi EX1200 1 Required
Grader Caterpillar 16H 2 Required
Grader Komatsu GD655–5 2 Existing
Jumbo Epiroc Boomer 282 4 Existing
Jumbo Atlas Copco Boomer M2C 2 Existing
Loader (FEL) LeTourneau L1350 1 Required
Scoop Tram Atlas Copco ST1020 6 cu. yd 3 Existing
Scoop Tram Epiroc ST14 8 cu. yd 7 Existing
Scoop Tram Atlas Copco ST1530 10 cu. yd 7 Existing
Shovel (hydraulic) Hitachi EX2600 1 Required
Truck (haul) Komatsu 830E 218 t 4 Required
Truck (haul) Komatsu HD785-5 91 t 3 Required
Truck (haul) Caterpillar 777 91 t 3 Required
Truck (underground) Atlas Copco MT436B 36 tons 3 Existing
Truck (underground) Atlas Copco MT5010 60 t 5 Existing

Personnel

Mine Management

Job TitleNameProfileRef. Date
Chief Executive Officer Sinead Kaufman LinkedIn May 17, 2024
Chief Operating Officer Matt Breen LinkedIn May 17, 2024
Infrastructure Superintendent Caleb Larocque LinkedIn May 17, 2024
Maintenance Superintendent John Nauss LinkedIn May 17, 2024
Mine Services Superintendent Joe Blandford LinkedIn May 17, 2024
Sr. Production Manager Kyle Buckoll LinkedIn May 17, 2024
Underground Projects Superintendent Nigel King LinkedIn May 17, 2024

EmployeesTotal WorkforceYear
871 1,334 2023
853 2022
646 2021
1,100 2020
1,124 2019
1,223 2017
1,187 2016
1,134 2015
948 2014

Aerial view:

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