VANCOUVER, BC / ACCESSWIRE / February 19, 2019 / First Mining Gold Corp. ("First Mining" or the "Company")(TSX: FF) (OTCQX: FFMGF) (FRANKFURT: FMG) is pleased to announce positive interim metallurgical test results for its Springpole Gold Project ("Springpole") in northwestern Ontario, Canada, that indicate the potential for significant increases in the ultimate recovery of both gold and silver from the project.

With oversight provided by M3 Engineering & Technology Corp. ("M3") in Tucson, Arizona, flotation test work completed by ALS Metallurgy ("ALS") in Kamloops, British Columbia achieved total recoveries of 90.6% for gold and 95.1% for silver through flotation followed by separate cyanide leaching of both concentrate and flotation tails.

This represents a 13.2% increase in gold recovery and an 11.9% increase in silver recovery over the Whole-Ore Carbon-in-Pulp ("Whole-Ore CIP") flowsheet presented in the independent Preliminary Economic Assessment ("PEA") technical report for Springpole1 that was prepared by SRK Consulting (Canada) Inc. in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101"), which demonstrated recovery levels of 80% for gold and 85% for silver2.

Dan Wilton, First Mining's Chief Executive Officer, said, "The increased recoveries demonstrated by these test results are very exciting and could add significantly to the robustness of Springpole, while at the same time improving our ability to engineer the project to minimize its environmental impact. Springpole is one of the largest undeveloped gold projects in Ontario and this potential increase in recoveries points to a strong potential for increased annual production, further moving Springpole into ''Tier I'' project status. First Mining will continue to advance this critical metallurgical program through further optimization and trade-off studies as we mo ve Springpole through the Pre-Feasibility process."

These interim results were achieved in flotation test #17 of the ALS program which first ground the original ore feed to a p80 of 145 microns (''?m''). This feed produced a rougher flotation concentrate at a mass pull of 23.9%, which was then cleaned to produce a cleaner concentrate at a mass pull of 12.4% (see Table 1 below). This cleaner concentrate was reground to a size of 17 ?m (P80) prior to cyanide leaching. The cleaner flotation tails were combined with the rougher tails for cyanide leaching.

One of the key discoveries of this metallurgical testing program was the consistently high recoveries achieved by leaching the flotation tails, even at relatively coarse grind sizes. Leaching the floatation tails achieved greater than 88% recoveries across all grind sizes tested. ALS also completed other tests in which the flotation concentrates were reground to 23?m and 24?m (P80), and these tests demonstrated total gold r ecoveries of 89.4% and 88.7%, respectively. A detailed list of the test results are detailed in Table 2 below.

This proposed flowsheet by M3 for Springpole is similar to other flowsheets that M3 has developed, where the concentrate is re-introduced into the flotation tails after fine grinding, whereas at Springpole, First Mining will continue to investigate maintaining a separate leach circuit and tailings stream for the higher-sulfur flotation concentrate. For Springpole, First Mining will investigate potential environmental advantages to maintaining a separate leach circuit and tails management facility for the concentrate from the tails products.

A flotation-centered flowsheet offers significant advantages over the Whole-ore CIP flowsheet including generation of a much smaller volume of material requiring ultrafine grinding (< 20 mm) for improved liberation, and sequestering up to 85% of total sulphides in a separate, much smaller tailings management facility.

The next stage of metallurgical testing will involve further investigation into flotation, fine and ultrafine grinding alternatives, and potential pre-flotation removal of silicate gangue and will eventually lead to locked cycle metallurgical testing to confirm the final processing flowsheet. This final flowsheet will be selected after completing trade-off studies on capital and operating costs prior to commencing a Pre-Feasibility Study fo r Springpole. Given the timeframe necessary to complete such a study, First Mining intends to complete an updated Preliminary Economic Assessment for Springpole to reflect a flotation and fine grinding-based flowsheet in order to assess the economic impact on the project of significantly higher recoveries and commensurate changes in capital and operating costs. The 2017 Springpole PEA generated a post-tax NPV5% of US$792 million, and a post-tax IRR of 26.2%, using 80% gold recoveries and 85% silver recoveries.

Readers are cautioned that the PEA is preliminary in nature, it includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Actual results may vary, perhaps materially. The projectio ns, forecasts and estimates presented in the PEA constitute forward-looking statements and readers are urged not to place undue reliance on such forward-looking statements. Additional cautionary and forward-looking statement information is detailed at the end of this news release.

Summary tables presenting the ALS results are presented below:

Table 1: Flotation Results

Table 2: Cyanide Leaching Results