The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
Arctic Canadian is having a remote-operated underwater continuous miner built to extract diamonds from flooded pits North of 60 Mining News – October 7, 2022
Aerial view of the Ekati diamond mine in Northwest Territories.
This 71.3-carat gem recently recovered at Ekati is likely the largest fancy vivid yellow diamond discovered in Canada.
The surface launch and recovery platform built by IHC Mining will support the underwater mining crawler being developed by the Netherlands-based firm.
The underwater crawler being built for the Ekati Mine will be a remote-operated continuous miner that excavates layers of kimberlite from the floors of flooded mining pits.
Underwater mining conjures images of the dredging up gold-rich marine placers off the beaches of Nome, Alaska, diamonds from the ocean floor of the coast of Namibia, or collecting potato-sized nodules of manganese off the deep-ocean floor. Arctic Canadian Diamond Company, however, has a completely different use for submersible mining technology – recovering diamonds from the bottom of previously mined pits that have since filled with water at its Ekati Mine in Canada's Northwest Territories.
Since its opening in 1998, Ekati has become renowned for the premium gem-quality diamonds it ships to global markets and has served as a pillar of Northwest Territories' economy. While the exact quantity of diamonds recovered at Ekati has been opaque since the Arctic mine went under private ownership in 2017, approximately 67.8 million carats of Ekati diamonds had been recovered through the end of 2016 and North of 60 Mining News estimates the total to now be north of 80 million carats.
While the total quantities produced over the past six years are cloudy, the gem-quality diamonds that have been recovered from Ekati are far from it. This includes a 186-carat diamond recovered from the Pigeon pit in 2016, the largest gem-quality stone recovered from Ekati thus far, and the 71-carat gem recovered earlier this year, which is likely the largest fancy vivid yellow gem-quality diamond ever recovered from a Canadian mine.
According to Arctic Canadian Diamond Company, which owns a controlling interest and operates Ekati, this iconic northern Canada mine has enough reserves to continue delivering diamonds to global markets until 2028.
Arctic Canadian Diamond President and CEO Rory Moore says the underwater remote mining system currently being developed "has the potential to significantly increase the mine life at Ekati and thereby provide the opportunity for Arctic to continue to make a positive socio-economic contribution to the North for many years to come."
The diamond-rich Ekati Mine is found on Canadian Shield, a vast and flat expanse of north-central Canada where lakes cover almost as much of the landscape as dry land. While the deep-seated craton –the stable interior portion of a continent that extends down into the upper mantle – of the Canadian Shield is a great place for the formation of the kimberlite pipes that carried the diamonds to the surface in this region, digging down into this waterlogged landscape can be challenging.
Water management has always been a key part of mining the kimberlite pipes at Ekati, which were formed when eruptions quickly transported diamond-bearing rocks from depths of 125 to 190 miles to the Earth's surface. The nearly perfectly round open pits at diamond mines are a reflection of the conical shape of the kimberlite pipe.
As the open pit mines at Ekati follow these kimberlite pipes deeper into the Canadian Shield, the management of water becomes more challenging and costly.
Instead of developing new water management techniques or leaving gems at the bottom of the pit because removing the water would be too costly, Arctic Canadian has decided to pioneer an underwater crawler that remotely mines the kimberlites at the bottom of the pits.
"Many other mining solutions were evaluated over the past 15-20 years, but the mining crawler is the technological breakthrough for kimberlite diamond mining we were looking for," said Jon Carlson, head of exploration and project development at Arctic Canadian Diamond. "With this solution we are taking the next step in the future of diamond-bearing kimberlite mining."
To develop the underwater remote mining system for Ekati, Arctic Canadian turned to the expertise of Netherlands-based IHC Mining – part Royal IHC, a global company that designs and builds a range of specialized equipment for mining, dredging, offshore, and defense industries.
Arctic Canadian and IHC Mining began working together in 2018 to develop an innovative and integrated mining solution that would have a much lower environmental impact than conventional mining methods.
What they came up with is a three-part underwater remote mining system that involves a submersible mining crawler, a floating platform that will help recover the diamond-bearing kimberlite ore mined from the deep open pits, and a plant to remove the water so the kimberlite can be processed through the existing diamond recovery facility.
IHC Mining is designing and building both the underwater mining crawler and floating support platform.
"We are very proud to be working with Arctic on this development," said IHC Mining Director Hans Greve. "The URM system perfectly matches IHC Mining's mission to deliver sustainable and responsible solutions for the mining industry."
This work began early this year with a contract to start on the launch and recovery platform, which was followed by a September contract to build an underwater mining crawler.
Equipped with the latest underwater positioning equipment and a drum cutter that excavates layers off the top of the kimberlite, the crawler is a continuous miner that eliminates the need for blasting. Ore excavated by this custom-built machine is pumped to the launch and recovery platform and then on to the dewatering plant.
The crawler system can operate at water depths of up to 400 meters.
The launch and recovery platform is scheduled for delivery to Ekati by the end of this year and will be tested next summer.
The mining crawler, which is being built at Royal IHC's facilities in the United Kingdom, will be delivered to the Northwest Territories diamond mine later in 2023.
With all the pieces in place, Arctic Canadian plans to trial the crawler in the Lynx pit, along with the surface components of the underwater mining system, during the summer of 2024.
It is expected that this underwater remote mining system will extract 150,000 metric tons of diamond-rich kimberlite ore from Lynx before being moved to other flooded pits at Ekati.
Arctic Canadian currently anticipates this innovative technological breakthrough for diamond mining could extend the life of the Ekati Mine by at least a decade.
In the meantime, exploration crews will look for new diamond-rich kimberlites at Ekati that can be mined from above and below water – further extending the ability of this iconic Canadian diamond mine to deliver gem-quality stones to global markets deeper into the 21st century.
Over his more than 16 years of covering mining and mineral exploration, Shane has become renowned for his ability to report on the sector in a way that is technically sound enough to inform industry insiders while being easy to understand by a wider audience.
Reader Comments(0)