The Sisson Project is an open-pit tungsten-molybdenum mining project located in New Brunswick, Canada. It is being developed by Northcliff Resources; a company associated with Canada-based Hunter Dickson (HDI), in partnership with Todd Minerals, a subsidiary of New Zealand-based Todd Corporation.
Northcliff is the operator and holds an 88.5% controlling stake in the project while the remaining 11.5% interest is held by Todd.
A feasibility study (FS) was completed in January 2013, while the Environmental Impact Assessment (EIA) for the project was approved by the provincial and federal governments in March 2015 and June 2017 respectively.
The construction works are expected to be started in 2022 as the Minister of the Department of Environment and Climate Change (DECC) of Canada granted a two-year extension for the construction commencement of the project in December 2020.
The Sisson project is expected to produce and process approximately 281 million tonnes (Mt) of ore over an estimated mine life of 27 years. It is expected to produce 557,000 metric tonne units (mtu) of ammonium paratungstate (APT) and 4.1 million pounds (Mlbs) of molybdenum annually.
Location, geology, and mineralisation
The Sisson tungsten-molybdenum project is located approximately 10km southwest of central New Brunswick and 100km northwest of Frederiction, near the communities of Napadogan, Juniper, and Stanley.
The project site occupies approximately 18,880ha in the Nashwaak Watershed area. It is accessible by the national railway line located approximately 15km away that connects to the deep seaports of Saint John and Belledune.
The geology of the Sisson project comprises contiguous I, II, III, and Ellipse Zones between two phases of the Howard Peak Granodiorite to the west, and metavolcanic and metasedimentary rocks to the east.
The tungsten and molybdenum mineralisation occurs in narrow, sheeted, northwest-trending quartz-sulphide veins surrounding larger north-trending shear veins. While tungsten occurs in the mineral scheelite and in wolframite, molybdenum is found in molybdenite.
Tungsten and molybdenum reserves at Sisson
The Sisson mine is estimated to hold approximately 334Mt of proven and probable ore reserves grading 0.066% tungsten and 0.021% molybdenum, containing approximately 22.2 million mtu of tungsten trioxide (WO3) and 154.8Mlbs of molybdenum.
Mining and ore processing
The conventional open-pit mining method involving drill, blast, load, and haul operations will be employed for ore extraction. The run-of-the-mine (ROM) will undergo crushing and floatation for the production of tungsten and molybdenum concentrate at an on-site ore processing plant.
The tungsten ore will be further refined at an APT plant involving alkali pressure leach technology for the production of ammonium paratungstate.
The final products from the mine will be trucked to nearby rail facilities for transportation to the seaports.
The other infrastructure facilities for the project will include a water treatment plant, a tailings storage facility, office buildings, laboratories, and a warehouse.
A new 138kV power transmission line will also be constructed for supplying up to 50MW of electricity to the Sisson project site.
While Stantec Consulting prepared the environmental impact assessment (EIA) report, Samuel Engineering completed the feasibility study for the project in January 2013.
Moose Mountain Technical Services was engaged for the mine design and production planning in 2012, while Jacobs Engineering Group was engaged for planning and engineering services for the plant and associated site infrastructure in June 2014.
Knight Piésold Consulting was engaged for geotechnical services, while Roscoe Postle Associates (RPA) provided the resource estimate for the Sisson Project.
Bolu Consulting Engineering was contracted for the concentrator design, while Gene Greskovich was engaged for the APT process, layout, and mechanical design.
Sisson tungsten-molybdenum project background
The Sisson tungsten-molybdenum deposit was discovered by Kidd Creek Mines in 1978. Geodex Minerals undertook the engineering studies and drilling operations at the site after taking over the project in 2004.
Northcliff entered into an agreement to acquire a 70% interest in the project from Geodex Minerals in 2010. It further acquired the remaining 30% interest from Geodex Minerals in June 2012.
Todd Corporation entered into a partnership agreement with Northcliff in October 2013 and became the 11.5% owner of the Sisson project after investing approximately £9m ($14m) on a staged basis by October 2014.