Published: September 11, 2023 |

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First Mining Gold has released the favorable outcomes of a preliminary economic assessment (PEA) conducted for its 100 percent owned Duparquet Gold Project, situated in the Abitibi region of Quebec, Canada.

The PEA findings endorse an operational plan involving both open-pit and underground mining, targeting a production rate of 15,000 tonnes per day over a projected mine life spanning 11 years. It’s essential to note that the PEA exclusively covers the Duparquet gold deposit situated within the Beattie, Donchester, Central Duparquet, and Dumico claim blocks and does not encompass the Pitt Gold and Duquesne deposits.

The initial capital costs are estimated to be C$706 million.

“This PEA demonstrates the robust economic potential of the Duparquet Gold Project. The +200 koz per year production profile, attractive capital and operating cost profile and strategic location of the deposit in the heart of the Abitibi gold belt all contribute to the recognition of Duparquet as one of the most meaningful development projects in Canada,” said First Mining CEO Dan Wilton.

“We are also pleased to have completed such a robust PEA within a year of consolidating the ownership of the project. Importantly, the Duparquet Gold Project represents a unique opportunity to address the environmental legacy issues from the historic mining operations while delivering an important economic development opportunity for the local and Indigenous communities around the project,” added Wilton.

“We look forward to continuing to work with regulators, the Municipality of Duparquet, and other local and Indigenous communities to advance this parallel track of environmental stewardship and economic development,” concluded Wilton.

The PEA for the Duparquet Gold Project was compiled by G Mining Services, based in Montreal, Quebec, in full compliance with the National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101).

MINING CAPITAL COSTS

The open pit mining activities for the project were assumed to be undertaken by an equipment financed fleet. Mining capital costs were estimated based on a detailed equipment schedule matched to the mining production schedule. Total initial mining capital was estimated at C$102 million, inclusive of capitalized stripping, and equipment. The capital expenditure for the underground, which starts at year one of open pit operations, is $404 million of which C$255 million is attributed to mine development.

PROCESSING CAPITAL COSTS

The process plant was designed using conventional processing unit operations. It will nominally treat 15,000 tpd or 679 dry tonne/hour based on 92 percent availability. The primary crushing plant design is based on 75 percent availability. The plant will operate two shifts per day, 365 days per year, and will produce a high-grade gold concentrate for sale to smelters.

Initial capital costs for the processing facility were estimated to be C$190 million, excluding contingency. No major plant re-build or expansion was considered during the LOM, with sustaining capital set to maintain the equipment in operating condition.

MINING COSTS

The PEA contemplates open pit and underground mining undertaken by an equipment financed fleet. An average unit mining cost of C$3.16 per tonne of material mined from the open pit was used in the economics. The cost estimate was built from first principles with detailed haulage profiles, and is based on experience of similar sized open pit operations and local conditions. The open pit mining costs consider variations in haulage profiles by month and by year and variable equipment requirements necessary to meet the plant production.

Underground mining cost was also estimated using first principles with supplier’s quotations for equipment, consumables, contractor work, and is based on experience with underground operations with similar size and environment. The underground mining costs of $44.26 per tonne of mineralized material mined from underground includes $2,257 per meter of OPEX development. A sustaining development cost of $16.64 per tonne is required to maintain production which is excluded from the operation costs.

MINING METHODS

The Duparquet Project is planned as a mix of conventional open pit mine and a long hole (transversal, longitudinal, uppers) underground mine.

Open pit mining will be done with the use of diesel equipment including drilling rigs and haul trucks coupled with hydraulic shovels. The project consists of seven pits with Pit 1 having three phases. The LOM will last for 11 years including a pre-production and construction period where waste will be mined for construction purposes (dams, roads, etc.) and mineralized material will be stockpiled ahead of the process plant commissioning.

Production drilling and mining operations will take place on a 10 m bench height. The primary production equipment includes 12m diesel-hydraulic shovel coupled with 65 tonnes Drammis trucks for the mineralized material and 22m diesel-hydraulic production shovels coupled with 200 tonnes off highway mining trucks for the waste. An owner mining operation is planned with overburden stripping, topographic drilling activities, and supply of explosives outsourced to contractors.

For the underground mine, long hole stopping, both transverse and longitudinal with cemented rockfill (CRF) is the preferred mining method. Mineralized material will be removed from the stopes using a high production sized load-haul-dump (LHD). The underground mine’s main declines will be accessible from surface through a single portal located north of the site.

In addition to the open pit and underground mines, a portion of the historical tailings will be transported and processed at the mill. A maximum of 750,000 t of material will be processed yearly.

PROCESSING

The preliminary process plant design for the Duparquet Project is based on a robust metallurgical flowsheet to treat gold bearing material to produce gold concentrate. The flowsheet is based on previous metallurgical test work by Clifton Star, industry standards and conventional unit operations.

The process plant is designed to nominally treat 15,000 tpd of mineralized material and reprocessing of existing tailings. The flowsheet will consist of primary crushing, SAG and ball mill grinding, rougher and cleaner gold flotation circuits, concentrate dewatering and load out facilities. Flotation tailings will be dewatered in a thickener to produce a tailings slurry for storage onsite. The process plant will include reagents, air systems and utilities to support the operation.

SITE INFRASTRUCTURE

The project is located immediately north of the town of Duparquet with much of the site infrastructure optimized to utilize existing infrastructure within the town of Duparquet. No camp is planned on site and the administrative offices, the light vehicle truck shop and warehouse, among others are considered off site. The operation buildings, which will include the security office, offices for technical personnel, the conference rooms, a change room, an infirmary and a lunchroom, will be located at site entrance. An on-site temporary workshop is included in the initial capital with the permanent truck shop planned in year four. The assay lab, the fuel storage (200,000 liters) and the explosive magazine among other essential infrastructure are also considered on site.

The infrastructure and process plant platform will be located on the north side of the pits. The waste rock stockpiles will be located on each side of the pits. A haul road is planned to connect the pits to the waste stockpiles, overburden stockpiles, process plant and tailings storage facility.

TAILINGS STORAGE FACILITY

The tailings storage facility (TSF) design will take advantage of the existing topographic and ground conditions in the eastern part of the project site. The TSF will provide enough capacity for 34.5 million cubic meters of tailings. A tailings deposit basin will be created by building a main dam at the downstream end of the valley and the tailings dams will be constructed in phases to minimize the initial capital. The process plant tailings will be pumped to the TSF through a 4 km pipeline and will be thickened prior to deposition. The reclaim water system will consist of a reclaim barge equipped with two reclaim water pumps.

ENVIRONMENT AND COMMUNITY

The PEA has considered and incorporated the opportunity to leverage the Duparquet Gold Project development with the reclamation of the brownfield site conditions including the removal and reprocessing of over 4.1 Mt of uncontained historical mine tailings. With such measures incorporated into the PEA mine plan, in combination with the ability of the project to collect and treat historically impacted groundwater via the excavation and dewatering of the open pit, the project is positioned to deliver both environmental benefits and socio-economic benefits via employment, contracting and revenue for the Municipality of Duparquet. The PEA is anticipated to be refined and optimized based on consultation and input to be received by government, the Municipality of Duparquet, and other local and regional stakeholders, and local First Nation community.

Since acquiring the Duparquet Gold Project in September of 2022, First Mining has prioritized meeting the people, communities, and government representatives on project planning in an open and transparent manner. First Mining published the Mines d’Or Duparquet website to share project information and has recently finished renovations required to open a First Mining community relations office in Duparquet. The project provides an opportunity to address historical environmental aspects at the project site to improve long-term sustainability, economic activity, and support sustainable municipal planning and development.

The Municipality of Duparquet is in the Abitibi-Témiscamingue region which has been shaped primarily by natural resource-based industries, including mining, and forestry, where the mining industry accounts for one in seven jobs in the region.

First Mining Gold is a gold developer advancing two of the largest gold projects in Canada, the Springpole Gold Project in northwestern Ontario, and the Duparquet, Pitt and Duquesne Gold Projects in Quebec, a collection of advanced stage development assets located on the Destor-Porcupine Fault in the prolific Abitibi region. First Mining also owns the Cameron gold project in Ontario and a portfolio of gold project interests including the Pickle Crow gold project, the Hope Brook gold project, an equity interest in Treasury Metals Inc., and a portfolio of 21 gold royalties. First Mining was established in 2015 by Mr. Keith Neumeyer, founding president and CEO of First Majestic Silver Corp.

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