The Sisson open-pit tungsten and molybdenum mine is located in central New Brunswick, Canada. Northcliff Resources and Todd Minerals are jointly developing the project under a partnership called Sisson Project Limited Partnership.
The project’s feasibility study completed in January 2013 and the environmental impact assessment (EIA) report was submitted in July 2013. The two-year construction phase is expected to start in 2015, while production is expected to begin in 2017.
The project is estimated to require a capital investment of $579m and is expected to create approximately 500 construction jobs and up to 300 operational jobs. The anticipated mine life of Sisson is 27 years.
Sisson project history, location and geology
Kidd Creek Mines discovered mineralisation at the project in 1978 and conducted exploration drilling until 1982. Geodex Minerals acquired the mine in 2004 and conducted subsequent delineation drilling from 2005 to 2009. In November 2010, Northcliff acquired 70% interest in the project from Geodex and the remaining stake in June 2012.
The project is located on Crown land, approximately 100km north-west of Fredericton, and is in close proximity to Napadogan, Juniper, and Stanley communities. It is hosted within five contiguous claim groups of 850 units extending over 18,880ha.
Mineralisation at the deposit is contained in four contiguous zones of which, zones I and II are narrow, structurally controlled zones. Zone III hosts the bulk of the deposit, while the Ellipse zone extends north-west from the south-west corner of Zone III.
Most of the mineralisation at Sisson is located within narrow, north-west-trending quartz-sulphide veins. Tungsten is found mostly in the mineral scheelite, while molybdenum occurs in molybdenite. Mineralisation extends over a strike length of 1,900m, with an average width of 650m and average depth of 350m.
Reserves of Sisson project
The Sisson project is estimated to contain proven and probable reserves of 334Mt of ore grading at 0.066% WO₃ and 0.021% Molybdenum. It is expected to contain 22.2Mt units of WO₃ and 154.8 million pounds (Mlb) of molybdenum.
Mining and processing
Sisson will be mined using the conventional truck-and-shovel mining method. The mining fleet will comprise 136t trucks, 16.5m³ hydraulic shovels and support equipment.
The ore will be processed using crushing, grinding and flotation to produce both molybdenum and tungsten concentrates. Along with the standard processing methods, the project will also make use of a processing plant to produce ammonium paratungstate (APT) from the tungsten concentrate. The APT plant is the first of its kind in Canada and is expected to process 281Mt of ore over the mine life.
The mine is estimated to produce an average of 557,000mtu of APT and 4.1Mlb of molybdenum concentrates a year.
Financing for the Sisson project
Northcliff Resources and Todd Minerals, a subsidiary of Todd Corporation, entered into a limited partnership agreement to develop the project in October 2013. Under the agreement, Todd agreed to provide $39m for the project development.
The funding was made in three tranches, the first tranche of $5m completed in October 2013, the second of $5m in April 2014, and the remainder in October 2014. Todd Minerals acquired an 11.5% interest in the Sisson mine by investing $14m. It also holds an option to acquire an additional 10% interest in the limited partnership by investing $20m.
The Sisson property site can be accessed from the existing forest roads from Highway 107, 2, and 104.
Power supply for the project will be provided from the existing New Brunswick (NB) electrical grid, through a 42km-long, 138kV transmission line to be constructed by NB Power alongside the existing 345kV line crossing the Sisson claim block.
In addition to the open-pit mine and the APT plant, the project will also feature infrastructure facilities such as a water treatment plant, tailings storage facility, office space and warehouses.
Key Players involved with the Sisson mining project
Jacobs Engineering Group received the Value and Basic Engineering contract for the Sisson tungsten-molybdenum project in June 2014. The contractual scope includes planning and engineering services for the processing plant and associated site infrastructure of the mine.
Societe Generale Corporate & Investment Banking was contracted in March 2014 to serve as the financial advisor for the Tungsten-Molybdenum project.
Denver-based company Samuel Engineering conducted the feasibility study for the project. Stantec was engaged to prepare the EIA report.