Abstract
The Bulk Tonnage Open Pit Baptiste “Porphyry” Nickel Deposit in Central BC
Peter M D Bradshaw(1), Trevor Rabb(2), Martin Turenne(1)
(1)FPX Nickel Corp, (2)Equity Exploration Consultants Ltd
The Baptiste deposit and several other known occurrences, including the recently drilled Van target, define the Decar Nickel District in Central BC. The Baptiste deposit is the most advanced deposit in the district with recent work including a PEA completed in 2020. Mineralization throughout the Decar Nickel District occurs as uniformly disseminated nickel-iron alloy mineralization amenable to bulk tonnage open pit mining with an extremely low strip ratio. The mineralization occurs as disseminated awaruite, a Ni-Fe alloy (Ni3Fe), that is highly ferro magnetic. Mineralization is broadly disseminated and remarkably uniform with negligible sulphides, removing the potential for acid rock drainage. The Baptiste deposit’s Indicated Mineral Resources include 2Bt grading 0.122% Davis Tube Recoverable (DTR) nickel, containing 2.4Mt of nickel (5.3B lbs of nickel), at a cut-off grade 0.06% DTR nickel.
No common term exists for this previously unrecognized style of deposit and the authors propose "Porphyry Nickel" as a general term to contextualize the mineralization in the Decar District.
Metallurgical recovery includes a fine crush followed by magnetic separation to produce an awaruite-magnetite concentrate followed by floatation to produce separate concentrates of awaruite (~60% Ni) and magnetite (~60% Fe). Pelletizing of the awaruite concentrate is amenable for either direct feed into a stainless steel furnace, or production of nickel sulphate and cobalt sulphate commonly used for the production of batteries, through leaching under moderate temperature and pressure.
As described in a 2020 PEA, cycloned tailings will be deposited in a conventional tailings management facility. Test work at UBC demonstrates that the tailings will passively sequester some level of CO2 that combines with MgO in the host rock to form stable MgCO3. As the mill will use hydro power it is estimated that the tailings will naturally sequester the CO2 produced by mining equipment and Baptiste can be a carbon neutral mine.
Comparisons will be made with porphyry copper deposits in BC