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Argonaut reports positive results for feasibility study for Canadian gold project

Published 08 November 2017

Argonaut Gold has revealed the results of a feasibility study for its 100% owned Magino gold project located 40km northeast of Wawa, Ontario, Canada.

A 10,000 tonne per day processing facility was selected for the FS in order to significantly reduce the initial capital requirement. This differs from the 30,000 tonne per day project presented in the January 2016 pre-feasibility study ("PFS") and provides the Company with a scalable project, which it can fund on a stand-alone basis, if a decision is made to proceed with the Project. 

The Project is designed to allow future expansion should economics warrant such a decision. A 30,000 tonne per day scenario was also evaluated, is summarized in this press release and will be described in summary in the Other Relevant Data section of the National Instrument ("NI") 43-101 Technical Report scheduled for filing within 45 days. All dollar amounts are expressed in United States dollars, unless otherwise specified (C$ refers to Canadian dollars).

Pete Dougherty, President & CEO stated: "We believe this FS demonstrates that Magino is a strategic, long-life asset in an attractive mining jurisdiction, Ontario. We have been able to appropriately scale the Project to a manageable capital number while providing the optionality of expanding the scale of the project in the future either through operational cash flow during Magino's life or through a potential joint-venture partnership. The 10,000 tonne per day project reports an average grade of 1.4 g/t Au during the first five years and 1.2 g/t Au during the 14 years of active mining. With a strong cash position, zero debt and the expectation of solid cash flow from our Mexican operations as we execute on our 60% production growth plan between 2017 and 2019, we feel that the $321 million initial capital estimate is a manageable investment for the Company, at the right time, given our ability to add debt capacity at either the corporate or project level and the cash flow anticipated from our Mexican operations. We have also been mindful when developing mine plans and designing the process facility not to sterilize the ore body and ensure proper space is available should economics warrant an investment to expand the Project to 30,000 tonnes per day in the future. Given our internal growth profile, we are focused in the near term on that growth. Decisions on Magino will be made when and if it is appropriate. The size, location, economics and expandability of Magino give Argonaut significant flexibility to explore options around the Project on its own or with partners."

The FS assumed $1,250 gold and a 0.78:1 United States dollar to Canadian dollar exchange rate. The FS yields average annual production of approximately 116,000 gold ounces over a 17 year mine life (including three years of ore processed from a low grade stockpile), an average of 150,000 gold ounces during the first five years and an average of 123,000 gold ounces during the 14 years of active mining.  Estimated cash costs and all-in sustaining costs ("AISC") are $669/oz and $711/oz respectively (see Non-IFRS Measures section).

Mineral Resource Estimate

A conceptual pit was generated in order to constrain the tabulation of Mineral Resources. A gold price of $1,300 was used along with other cost, recovery and slope parameters. Mineral Resources were estimated in the conceptual pit using a 0.25 g/t gold cut-off grade.

Mineral Reserve Estimate

The Mineral Reserve estimate for the Magino open pit was constrained with estimates of gold price, mining dilution, process recovery, operating costs, pit slope angles, and refining/transport costs.

The Mineral Resource block model for the Magino deposit was then used to determine optimal mining shells and pit phasing. Measured and Indicated Mineral Resources were included in the pit optimization process. Inferred Mineral Resources within the designed open pit are treated as waste.

Detailed pit and phase designs were created based on the pit optimization results. These designs incorporated geotechnical parameters as well as ramp accesses and formed the basis of the Mineral Reserve estimate.

A gold cut-off grade of 0.41 g/t was used to calculate the Mineral Reserve estimate for Magino.

Mineral Processing, Metallurgical Testing and Recovery Methods

The metallurgical testing was completed at McClelland Laboratories Inc. Recent work focused on optimizing processing conditions and a further evaluation of ore variability within the Magino deposit. The testing program included gravity concentration and leach optimization testing.

Results from the program suggest an optimum grind size of P80 75 microns, demonstrated gold recoveries ranging from 90 to 94% from an average head grade sample of 1.31 g/t Au. The work confirmed the basic flowsheet previously adopted in the January 2016 PFS but resulted in some optimization design criteria detail such as leach retention time and reagent consumption data.

Flowsheet development and design criteria were based on metallurgical test work results. The process plant was designed on a throughput of 10,000 tonnes of ore per day with an average gold head grade of 1.25 g/t and to achieve an overall 92.0% gold recovery. The adopted flowsheet includes primary crushing, single stage semi-autogenous grinding, a gravity recovery circuit, cyanide leach and carbon-in-pulp gold adsorption circuit with cyanide recovery and detoxification and thickening prior to tailings discharge to a tailings facility.

Mine Plan and Production Schedule

Open pit mining of the Magino deposit is intended to produce a total of 59.0 million tonnes (Mt) of ore and 232.4 Mt of waste for a 3.9:1 overall strip ratio, over a 15-year mine production life (including one year of pre-production). The current life of mine plan focuses on achieving consistent ore production rates, and mining of higher value material, as well as balancing grade and strip ratios. Lower grade material that is above the marginal cut-off but below the operational cut-off will be stockpiled and processed at the end of mine life (years 14 through 17).

Open pit mining operations will use a fleet comprised of 16 m3 front shovels, a 13 m3 front-end loader and 140 t haul trucks. This fleet will be supplemented by drills, graders, and track and rubber-tire dozers. A 5 metre working bench height was selected for mining in ore and waste with overall 10 metre effective bench height based on a double bench configuration.

Mining will begin at the Project in the year preceding full operations to provide waste rock for general construction, as well as construction of the first lift of the containment structure at the tailings facility. This will also enable the stockpiling of higher grade ore prior to the start of mill processing. Mill processing will commence in year 1. Open pit mining will be completed in the first half of year 14. Mill processing of lower grade material will continue until the first quarter of year 17.

Capital Costs

The capital cost estimate includes the costs required to develop, sustain, and close the operation for a planned 17-year mine life, which includes three years of processing low grade, stockpiled material. Major construction at site is expected to take place over a 24-month period. The sustaining capital is carried over operating years one through 16 and closure costs are projected over years 17 to 22.

Operating Costs

The FS operating cost estimate includes the costs required to mine, handle and transport ore to the mill, mill and process the ore to doré, general and administrative expenses, as well as water treatment plant operating costs.

Environmental Assessment and Permitting

The Company submitted its Environmental Impact Statement in January 2017 and the environmental permitting process is well underway. Federal and provincial regulators have completed their conformity review and held Indigenous and public sessions. Currently, the Company is responding to technical comments and continues its substantive engagement activities with the federal and provincial governments, as well as Indigenous communities, local municipalities and other community stakeholders.

The Company anticipates providing responses to technical comments during the fourth quarter of 2017, which would target final environmental assessment and closure plan approvals during 2018. This, in turn, will allow the Company to apply for and receive necessary permits to begin construction of all major infrastructure.

Formal agreements have been signed with the Missanabie Cree First Nation and the Red Sky Métis Independent Nation. The Company continues to consult with and work towards agreements with other Indigenous communities.

30,000 Tonne Per Day Opportunity

While the FS offers a strong economic result, represents the preferred option and is expected to be the best use of the available Mineral Resources considering the current market conditions and Company profile, an increased throughput option at a processing rate of 30,000 tonnes per day was also evaluated ("30ktpd Case"). The Company believes that 30,000 tonnes per day throughput provides interesting project optionality for the future on a stand-alone basis should economics support such a decision. The Company also sees a path whereby the 30ktpd Case could be fully evaluated and pursued as a preferred development scenario for the Project should Magino become part of a joint-venture agreement with a third party that provides greater value for Argonaut shareholders than the FS.

The 30ktpd Case is preliminary in nature and is based on the same Measured and Indicated Mineral Resources as stated in the FS, does not support Mineral Reserve estimation and should not be considered an update or replacement for the FS. The 30ktpd Case is only intended to show the potential of an increased throughput should market conditions change or an alternative commercial structure that potentially provides greater value to Argonaut shareholders than the FS is successfully negotiated.

Mine Plan Comparison

The 30ktpd Case used a lower cut-off grade than the FS to account for the decreased unit operating costs associated with higher production rates. In general, the marginal cut-off grade used was 0.34 g/t Au. Only Measured and Indicated Mineral Resources from the FS were used in the 30ktpd Case conceptual mine plan.  Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

The total mineralized material that is above the marginal cut-off grade in the 30ktpd Case is approximately double that in the FS. However, due to higher plant throughput, the grade is approximately 0.2 g/t lower and the mine life is approximately six years shorter. Contained gold is increased by approximately 1.1 million ounces.

Economic Analysis

The economic results for the 30ktpd Case utilized the same assumptions as the FS ($1,250 gold and 0.78:1 USD:CAD exchange rate). The 30ktpd Case yields average annual production of approximately 269,000 gold ounces over an 11 year mine life (including one and a half years of ore processed from a low grade stockpile) and an average of 319,000 gold ounces during the first five years. Estimated cash costs and AISC are $664/oz and $721/oz respectively (see Non-IFRS Measures section).

Bill Zisch, Chief Operating Officer, commented: "We are fortunate that the Magino deposit is an ore body that lends itself to scalability. Having the ability to right size the Project, in terms of initial capital, for our size of company and current market conditions while maintaining optionality for the future is a significant benefit to the organization. We will continue through the Environmental Assessment process and permitting and then gauge market conditions and all available options for Magino to best unlock value for our shareholders."



Source: Company Press Release