IDM Mining Reports Improved Metallurgical Test Results and Updates Progress on Red Mountain Feasibility Study

April 12th, 2017, Vancouver, BC – IDM Mining Ltd. (TSX.V: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

  1. Metallurgy

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 µm 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. Results by zone are as follows:

Zone Au Recovery (%) Ag Recovery (%)
Marc average 93.3 91.8
AV average 86.2 81.5
JW average 88.4 84.2

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 µm and CIL processing to produce gold-silver doré bars was selected.  The processing plant flowsheet is complete, and feasibility level design is underway.

  1. 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.

  1. 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.

  1. 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. 

About Red Mountain

The 17,125 hectare Red Mountain Gold Project is located in northwestern BC, 15 km northeast of the Town of Stewart.  IDM is advancing a Feasibility Study for a high-grade, underground gold mine, which envisions primarily bulk underground mining methods and the production of gold doré on site.  The Project is advancing through the provincial and federal environmental assessment processes, with comprehensive, thorough, and ongoing consultation with Nisga’a Nation.

Additional information, including the Company’s NI 43-101 Technical Reports for the Red Mountain gold project, is available at and at


Oversight of the Feasibility Study is performed by Wayne Corso, P. E. a consultant to IDM and ‘Qualified Person’ under NI 43-101.  Rob McLeod, P. Geo, President and CEO of IDM Mining Ltd. has reviewed and approved the technical content of this release.


IDM Mining Ltd. is a mineral exploration and development company based in Vancouver, BC, Canada.  The Company's current exploration and development activities are focused on precious metals in British Columbia, with a primary focus on the high-grade, underground Red Mountain Gold Project, which is advancing through the BC and Canadian environmental assessment processes.

of IDM Mining Ltd.

“Robert McLeod”

President, CEO and Director

For more information, contact:

Robert McLeod
604-681-5672 direct
604-617-0616 cell
[email protected]

Investor Relations:
Shobana Thaya
[email protected]

Alex Horsley
[email protected]
604 618-3058

“Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.”

Forward-Looking Statements: Some statements in this news release contain forward-looking information or forward-looking statements for the purposes of applicable securities laws.  These statements include, among others, statements with respect to the proposed exploration and development activities and their timing, resource estimates and potential mineralization, the anticipated timing for completion of a feasibility study for the Project.  These statements address future events and conditions and, as such, involve known and unknown risks, uncertainties and other factors, which may cause the actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the statements.  Such factors include, among others and in addition to those described elsewhere in this release, timing and success of future exploration and development activities, exploration and development risks, delays in obtaining or inability to obtain required government or other regulatory approvals, permits or financing, the risk of unexpected variations in mineral resources, grade or recovery rates, of failure of plant, equipment or processes to operate as anticipated, of accidents, labor disputes, and unanticipated delays in completing other development activities, the risk that estimated costs will be higher than anticipated and the risk that the proposed mine plan and recoveries will not be achieved, equipment breakdowns and bad weather, the timing and success of future exploration and development activities, exploration and development risks, mineral resources are not as estimated, title matters, third party consents, operating hazards, metal prices, political and economic factors, competitive factors and general economic conditions.  In making the forward-looking statements, the Company has applied several material assumptions including, but not limited to, the assumptions that: required regulatory approval, permits and financing will be obtained; the proposed exploration and development will proceed as planned; with respect to mineral resource estimates, the key assumptions and parameters on which such estimates are based; that the proposed mine plan and recoveries will be achieved, that capital costs and sustaining costs will be as estimated, and that no unforeseen accident, fire, ground instability, flooding, labor disruption, equipment failure, metallurgical, environmental or other events that could delay or increase the cost of development will occur, and market fundamentals will result in sustained metals and minerals prices.  The Company expressly disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise except as otherwise required by applicable securities legislation.


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