Noront Resources intends to open the first mine in the Ring of Fire. And in building that mine, it plans to use technological innovation that could guide the development of other mines in the James Bay Lowlands and elsewhere.
When Cliffs Natural Resources late last year suspended activities associated with its proposed Black Thor chromite mine, Noront suddenly found itself the mining company “leading the charge” in the Ring of Fire, as MP Greg Rickford put it shortly before his appointment in March as Canada’s new minister of natural resources.
Alan Coutts, Noront president and CEO, this spring expressed hope construction of his company’s Eagle’s Nest mine for nickel, copper, platinum and palladium could start during next winter road season, and be operating by the end of 2017.
Noront reached an important milestone in that direction, he said, with the completion in December of a draft environmental report. The report is necessary to meet requirements for a provincial environmental assessment (EA) of the Eagle’s Nest project and for a related federal environmental impact statement (EIS). A draft version has been circulated for review and comment by the public and government agencies.
Available on Noront’s website, the massive report is organized in four volumes. The main EA/EIS report section, Vol. 2, runs over 865 pages. Even the table of contents is nine pages long. Other volumes of the report include a Cumulative Effects Assessment and an Environmental and Social Management Plan. Main points are presented in an executive summary, Vol. 1.
Noront notes in the report there are two key technological innovations proposed for Eagle’s Nest: the mine’s processing mill will be placed underground, as will all of its tailings and waste rock; and a specialized design will be used in building an all-weather road across muskeg to the mine. “These are unique approaches to mine development.”
Underground
From early in the design process for the Eagle’s Nest mine, Noront recognized working in a peat bog with little dry ground would require innovative methods, says Mark Baker, an engineer and Noront’s vice-president of projects.
For starters, Noront plans to set up the mine’s processing facility underground.
This has been done at mines in other parts the world, for various reasons.
“Mineral processing plants have been placed underground elsewhere … when conditions like avalanche risk have warranted it,” Baker says in written response to questions from Onotassiniik. “Mineral processes like grinding the rock into fine particles have also been moving underground to reduce the cost and time for hauling rock to a surface mill.” In the case of Eagle’s Nest, he says, “Noront decided to minimize surface infrastructure because limiting surface disturbance is important to local communities and non-governmental organizations.”
Even more unique is Noront’s plan to keep underground all tailings (waste material) from the process that upgrades the mineral concentrate. This hasn’t been done before, Baker points out.
It makes sense at Eagle’s Nest in part because at the surface there isn’t the rock needed for building roads, an airstrip or pads for infrastructure above ground, such as accommodation and office buildings. As a result, aggregate for these construction purposes will come from rock mined during the underground development. “Noront’s decision to mine the Canadian Shield rock in underground caverns created space underground to hold all waste products (tailings),” Baker says, and makes unnecessary any surface tailings ponds.
Eagle’s Nest holds high-grade ore, he says, which means 3-4 per cent of the total rock to be mined is nickel, copper, platinum and palladium. Mineral processing will separate the valuable metal-bearing rock from other rock, producing a concentrate with 15-20 per cent valuable metal content. This concentrate will be dried at the surface next to a power plant to make use of waste heat, and then be hauled from the mine site destined for a smelter in eastern Canada.
The leftover tailings will be stored underground.
In areas where the ore has been mined, Noront proposes blending the tailings with cement and water so structural properties can be gained when the large openings are filled. This is important, Baker says, since sections next to these mined-out areas will also be mined after the cemented tailings have solidified and can help support the walls.
This ‘backfilling’ will only use some of the tailings. The remaining tailings can be placed in the openings created to mine aggregate rock used for road building and other uses on surface.
Roadwork
The best transportation route, north-south or east-west, and method, all-weather road or rail, to support future mines in the remote Ring of Fire has been the subject of study, debate and legal wrangling over the past couple of years. Currently, the Ontario Government is working to create a Ring of Fire development corporation of stakeholders in the region, including industry and First Nations, to make decisions about transportation and other infrastructure.
Noront has always preferred an east-west road linking Eagle’s Nest, 700 kilometres north of Thunder Bay, to get its concentrate to market and supply Eagle’s Nest with equipment and materials. It proposes an all-weather road, close to 300 kilometres long, from the Pickle Lake North Road to the mine. The first 200 km mostly follows an existing winter road alignment. The company contends this road can be built at a lower cost than other options for accessing the Ring of Fire, and that it would benefit the most remote First Nation communities (Neskantaga, Nibinamik, Eabametoong and Webequie previously proposed a similar route for an all-weather road to the provincial highway network).
Environmentally, Noront notes in its EA report, using the winter road path will: minimize impacts because the corridor has already been disturbed; have less impact on high-quality caribou habitat; and avoid any major river crossings and provincial waterway parks.
“It’s not necessarily guaranteed that this will be the road that will be first built,” Coutts said in April after attending a Ring of Fire forum in Thunder Bay. “We’re hoping it is. There’s only one mining company that’s actually going through this EA and permitting process, … developing its project, and that’s us.”
Noront budgeted capital expenses of $600-700 million for Eagle’s Nest but didn’t include the cost of building the all-weather road (or branch roads to First Nation communities). “What we’re assuming is that we will be a user of this large-scale infrastructure that the provincial and the federal governments, and maybe some other parties, will build it and we will pay a toll,” Coutts explained. In a feasibility study for Eagle’s Nest, he said, Noront accounted for paying a road toll of $10 million per year for the first 11 years of the mine.
It also prepared detailed engineering for the road.
While traditional road building removes all organic layers and excavates to load-bearing material – “In a wetland this would require excavating down many metres; over 20 m in some cases,” says Baker – Noront proposes an alternate method.
“Wetland road-building techniques have been developed that use woven cloth and mesh – geogrid – placed across wider road bed dimensions to create structural properties that allow the road to be built on top of the wetland,” Baker says of the technique, which has been applied in northern Saskatchewan, Alberta, the southern U.S. and other parts of the world. “The weight of the road materials compresses the strong fibrous peat and a lower level of the geogrid distributes the weight of the materials. An upper level of geogrid distributes the weight of the haulage vehicles.”
When the Eagle’s Nest mine is in production, a dozen trucks, each with 35-tonne capacity, will carry concentrate daily across the new road, the Pickle Lake North Road and Hwy. 599 to a trans-load facility on the Canadian National Railway mainline, near Savant Lake.
There’s another benefit to Noront’s road design. “Regular placement of culverts along the road ensures water continues to flow through the road to keep the wetland saturated, not cutting off the natural flow in the peat,” Baker says.
Learning Experiences
Development of Eagle’s Nest as the first mine in the Ring of Fire “will mark an important new chapter in the story of northwestern Ontario,” Noront proclaims in its EA report.
And the company’s unique approaches to mine development “will provide valuable learning experiences that may set precedents and help guide future mine developments” in this region and beyond, the report suggests.
Noront also hopes these innovations will contribute to approval of a final EA/EIS report before the end of this year, in time for road construction to start during the winter of 2014-15.