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Los Filos Gold Mine
Producing gold in Mexico
Los Filos has been operating since 2008 as both an open-pit and underground mining and heap leach complex.
160,000-180,000 oz gold
$1,680-$1,865 per oz AISC
5,354 Koz @ 0.86 g/t gold
7,897 Koz @ 0.75 g/t gold
Mining and processing
Open-pit and underground / heap leach
Estimated mine life
~10 years + Phase 2 expansion
The Los Filos Mine Complex is located in Guerrero State, Mexico, approximately 200 km southwest of Mexico City. Current operations comprise three open pits (Los Filos, Bermejal and Guadalupe) and two underground mines (Los Filos and Bermejal), with ore from all deposits processed by heap leaching. Development and operation of the Bermejal underground mine was temporarily suspended in February 2023.
Los Filos has been operating since 2008. Equinox Gold assumed ownership of the mine in March 2020 through its acquisition of Leagold Mining. Equinox Gold continued with expansion plans, including development of the Guadalupe open pit and the Bermejal underground mine, and in October 2022 announced the results of an updated feasibility study contemplating construction of a carbon-in-leach (CIL) plant to process higher-grade ore from underground and open-pit sources. Building and operating the CIL plant in conjunction with continued operation of heap leaching, as compared to a heap leach only scenario, would extend the mine life by four years and increase gold production to on average 280,000 ounces of gold per year, with peak production of more than 350,000 ounces per year. While the economic and production estimates outlined in the updated feasibility study assume construction of the CIL plant commencing in 2023, Equinox Gold has not yet approved construction and for now will continue processing all ore on the heap leach pads.
Production for 2023 is forecast at 160,000 to 180,000 ounces of gold with all-in sustaining costs between $1,680 to $1,865 per ounce of gold sold. Equinox Gold has engaged an efficiency consultant to identify opportunities to improve productivity and reduce costs at Los Filos. To this end, in February 2023 the Company announced the decision to suspend operations and development at the Bermejal underground deposit while the Company advances plans to improve productivity and reduce costs, with the objective of restarting Bermejal in the future.
Sustaining capital for 2023 is forecast at $40 million, primarily for open-pit waste stripping, underground development, fleet rebuilds and infrastructure improvements, and for exploration. Equinox Gold has not budgeted any non-sustaining capital at Los Filos in 2023.
|2023 Guidance||2022 Actuals||2021 Actuals|
|Gold produced (oz)||160,000-180,000||133,723||144,096|
|Cash costs ($/oz)||1,460-1,620||1,913||1,575|
|Sustaining capital ($M)||40||21||22|
|Growth capital ($M)||–||43||60|
Mining and Processing
Open-pit mining is owner-operated with conventional load, haul, drill and blast methods. Mining methods for the underground deposits vary depending on the ore geometry and ground conditions. In the Los Filos Underground, mining methods include overhand cut and fill in narrow areas, overhand drift and fill in wider areas, and longhole open stoping in areas with vertical ore body continuity and good rock conditions. In the Bermejal Underground, oxide ore has been mined using overhand drift and fill, which constitutes the majority of the deposit, and underhand drift and fill is used to mine ore in intrusive host rock. Bermejal Underground was suspended in February 2023 while the Company advances plans to improve productivity and reduce costs, with the objective of restarting Bermejal in the future
Mined ore is allocated to either run-of-mine or crushed ore heap leach facilities, as appropriate. Two heap leach pads are in operation, one for crushed ore and the other for run-of-mine ore. Crushed ore is fully leached after 120 days and run-of-mine ore after 180 days. Pregnant leach solution from the heap leach pads is processed in a conventional adsorption, desorption and recovery (ADR) process plant that also includes an elution circuit, carbon regeneration circuit and gold refinery that produces a gold-silver doré product.
Exploration and Geology
The Los Filos Mine Complex is in the Guerrero Gold Belt near the centre of a large, approximately 200 km diameter circular feature known as the Morelos-Guerrero sedimentary basin. The basin consists of a thick sequence of Mesozoic platform carbonate and argillaceous rocks. Mineralization identified within the Los Filos property is typical of intrusion-related gold-silver skarn deposits. Mineralization is geologically controlled either by being hosted by, or spatially associated with, skarn development during contact metamorphism of the carbonates by the intruding granitoid rocks.
The Los Filos stocks form two circular deposits, each approximately 1.5 km in diameter, with mineralization focused along the contacts with the host rocks. The Bermejal-Guadalupe stock forms an oblong shape over 5 km long, with the Bermejal deposit on the northern end and the Guadalupe deposit approximately 2 km southeast of Bermejal; the stock continues further southeast to the San Pablo deposit. Extensive, deep oxidation of the deposits (that occurred at the time of mineralization) has altered the mineralization to be amenable to cyanidation recovery techniques without the need of pre-treatment by roasting or other methods.
In the Los Filos area, known mineralization is associated with early-Tertiary Los Filos and Bermejal-Guadalupe granodiorite stocks that were emplaced into the host carbonate rocks. Mineralization in the Bermejal-Guadalupe area occurs along the contact of the Bermejal-Guadalupe stock with the carbonate rocks of the Morelos Formation. The Bermejal Open Pit mineralization is typically at the top or on the flanks of the upper portion of the intrusive. On the northern end of the stock, mineralization extends below the Bermejal Open Pit and down the steeply dipping to vertical flanks of the intrusion and is referred to as the Bermejal Underground deposit.
The total circumference of the Los Filos stocks is approximately 8 km, with at least half of this circumference tested by drilling or with mining development. The Bermejal-Guadalupe stock has a circumference of approximately 16 km, and although the contacts along the upper portion of the intrusion have been mined by open pit, only a few kilometres of this contact have been explored at depth.
Mineralization extends from surface to over 700 m deep and is variable in grade and width. Gold mineralization at Los Filos extends beyond the drilled area, and it is expected that additional drilling along the contact between the intrusives and carbonate host rock could identify further skarn mineralization. With exploration success and conversion of Mineral Resources to Mineral Reserves, considerable potential exists to extend the Los Filos mine life.