Bioleaching of black shales at the Property to recover metals offers significant Sulfur, H2S and CO2 consumption opportunities, with capacity to consume significant sulfur waste currently produced from oil sands operations in the Athabasca region. In addition, demonstrated CO2 sequestration opportunities exist with black shales elsewhere in the world which have not been fully tested in Alberta.
Taken together, these are environmental benefits rarely available from any typical mining operations anywhere.
The capacity of the envisaged metals recoveries process to also produce excess hydro offers further CO2 offsets as a significant contribution to GHG mitigation efforts in the region.
Prior leaching and bioleaching R&D testwork and studies of the mineralized Alberta black shales at the Property have identified many opportunities for significant enhancements to metals recoveries and related processing methods and enhancements to optimize reagent consumption to further lower the eco footprint of envisaged mining operations toward net-zero. These include the following:
- Early stage CO2 sparging tests and subsequent column testing conducted to explore CO2 sequestration possibilities concluded that CO2 can be used as a pre-treatment in the earliest bioleaching stages in lieu of Sulfur bio-innoculant leachate, offering opportunity to consume considerable CO2 while reducing Sulfur consumption. Lowering of the consumption of what is otherwise considerable waste Sulfur from oil sands operations whose destruction is a worthy objective as compared to the benefits of enhanced CO2 consumption is an unknown to be better clarified subject to willingness of oil sands producers to part with their Sulfur wastes and their CO2.
- The leaching R&D testwork, supported also by high resolution micro mineralogy studies, concluded that metals within the Alberta black shales are held in easily liberated ionic forms rather than trapped within sulfide minerals as they typically are in other black shales elsewhere which otherwise require aggressive acidic digestion to liberate the various metals from the sulfide mineralogies.
- Leaching R&D testwork concluded that metals are liberated quickly form the Alberta black shales subject to whatever form of “acidity” applied rather than what type of acid is used. The testwork also discovered that during a typical 210 day bioleaching gestation cycle, most of what is ultimately recovered at the end is recovered within the initial 50 day period. The foregoing offers significant opportunities to reduce surface disturbances related to leach pads clearing, or can enable processing of much larger mining throughput well beyond the 72MM tpa envisaged by the 2014 Preliminary Economic Assessment Study for the historic Buckton Deposit which offers a template for what might be achieved for other Mineralized Zones at the Property.
- Column Leaching R&D testwork concluded that “abiotic” metals processes can also recover metals from the shales in lieu of bio-leaching but at the expense of lower recoveries. Further expansion of prior testwork will better quantify benefits and trade-offs.
The Company will build on existing prior R&D work on shales from the Property to advance their potential as a serious contributor to GHG and waste Sulfur mitigation efforts in the region.