IDM Mining Ltd. (TSX VENTURE:IDM)(OTCQB:IDMMF) ("IDM" or the "Company") is pleased to announce that key technical work related to its Feasibility Study ("FS") is nearing completion for its Red Mountain Gold Project ("Red Mountain" or the "Project"), located 15 km northeast of Stewart, BC. IDM anticipates releasing the Feasibility Study within two months.
Key Feasibility Study Components Status Update
- Results from metallurgical testwork suggest Whole Ore Leach ("WOL") as the preferred process option
- Processing plant design is 80% complete
- Underground stope design is complete, mine development and infrastructure design is ongoing
- Tailings Management Facility ("TMF") design is 70% complete, based on best available technology ("BAT") assessment
- Access road design, including waterway crossings, is complete for lower section; 60% complete for upper section
JDS Energy and Mining ("JDS") is Project Lead for the FS with support from several independent engineering and consulting firms. In addition to Project oversight, JDS is completing underground mine design, metallurgy and Project economics. Allnorth Consultants Ltd. is completing process plant and site infrastructure design. Access road design and engineering is being completed by Onsite Engineering Ltd. SRK Consulting is responsible for hydrology, geochemistry and underground geotechnical work. Knight Piésold Consulting is leading the design of the TMF and water management systems.
"We are excited for the results of the Feasibility Study, which is incorporating the expanded and upgraded resource and increased gold grade from the 2016 preliminary economic assessment, as well as improved metallurgical recoveries," said Robert McLeod, President and CEO of IDM Mining. "Additionally, our 2017 underground resource expansion and exploration drilling program at Red Mountain is underway, targeting extensions along strike and down-dip."
Metallurgy and Processing
During the 2016 field season, mineral resource infill and metallurgical drill holes were distributed throughout the three primary resource zones at Red Mountain: the Marc, AV and JW Zones. Metallurgical test work and analysis was completed at Base Metallurgical Laboratories Ltd. This work included variability sample selection followed by comminution, minerology, gravity, leaching and flotation testing. The outcome of the program is that WOL using Carbon in Leach ("CIL") method with a 25 micrometer grind achieved consistently better metal recovery. Composite recoveries for Red Mountain average 89.4% Au and 86.1% Ag. This is an improvement from the 88.9% Au and 80.3% Ag average composite recoveries using the flotation-leach circuit contemplated in the July 2016 Red Mountain PEA.
Further metallurgical test work is currently underway with the objective of optimizing and improving recoveries, particularly in the AV and JW zones.
Due to close proximity to grid power and low British Columbia power costs, the fine grind to 25 micrometers and CIL processing to produce gold-silver doré bars was selected. The processing plant flowsheet is complete, and feasibility level design is underway.
2. Underground Mine Design
Underground stope design for the Feasibility Study was recently completed. Mining will primarily be longhole and transverse stoping along with cut and fill mining. Access, haulage and ventilation design is underway and is 50% complete. Work is ongoing to assess optimal scheduling and production rates from the underground.
3. Tailings Management and Design
Design work for the TMF is 70% complete. An extensive site investigation program of drilling, mapping and lab testing was performed at the proposed Bromley Humps tailings site during 2016. Design work will be completed to environmental assessment ("EA") and relevant BC Mines Act standards, which can be more detailed than feasibility-level design. IDM has been working closely with regulators and the Nisga'a Nation on the TMF design and assessment of alternatives, including incorporating Best Available Technology (BAT) into all aspects of the Project.
IDM has contracted Dr. Dirk Van Zyl as an independent third party peer reviewer for tailings and waste management engineering and design. Dr. Van Zyl, a professor with the University of British Columbia (UBC) Keevil School of Mining Engineering, is considered one of Canada's foremost experts in the field of TMF design and safety.
4. Underground Geotechnical and Hydrogeology
SRK Consulting gathered extensive surface, underground and drill core geotechnical data during 2016, supplemented by historical work at Red Mountain. Minimal ground support was required during the construction of the five by five meter decline in the early 1990s, and minimal work was needed by IDM during the 2016 underground rehabilitation work. SRK has completed stope design parameters and is currently finalizing its recommendations for ground support in both stoping and development areas. SRK is also modeling groundwater hydrology and chemistry. Significant but manageable melt water inflows were encountered during the 2016 summer months in the underground workings, and a water management plan will be included in the FS.