Forming part of the LaRonde Complex, the LaRonde Zone 5 mine (“LZ5” and formerly referred to as Bousquet Zone 5) is on the Bousquet property, approximately 2.5 km west of the Penna Shaft on the LaRonde mine property. Previous property owners had partly exploited the deposit by open pit. Following the completion of a positive internal technical study, LZ5 was approved in February 2017 for development. The full permits were received in 2017, and commercial production was achieved on June 1, 2018.
LZ5 has proven and probable mineral reserves of 686,000 ounces of gold (9.3 million tonnes grading 2.30 grams/tonne gold) as of December 31, 2019. Under the current LZ5 mine plan, a total of approximately 350,000 ounces of gold are expected to be mined through 2027. The Company is evaluating scenarios to integrate the additional mineral reserves in the down plunge of the LZ5 deposit, and the potential to extend operations at depth and along strike onto the Ellison property, which adjoins LZ5 to the west.
Geology
The LZ5 deposit is in the southern portion of the Archean-age Abitibi volcanic belt, within the Bousquet Formation of the Blake River Group of volcanic rocks. The deposit occurs within the east-west-trending Doyon-Bousquet-LaRonde mining camp, which includes the Mouska, Doyon, Bousquet 1, Bousquet 2 and LaRonde gold deposits. The most important regional structure is the Cadillac-Larder Lake fault zone, located approximately 2 km south of the Bousquet property.
Mineralization
The LZ5 horizon consists of a 4- to-30-metre-thick horizon of disseminated to stringer sulphide mineralization containing 5% to 20% pyrite and traces of chalcopyrite with rare millimetre-wide grains of visible gold. The LZ5 horizon has a large geological footprint and has been estimated to contain a mass of more than 26 million tonnes. The LZ5 horizon can be followed over 900 m of east-west strike length over the Bousquet property and another 400 m on the Ellison property for a total strike length of 1,300 m. LZ5 has been traced vertically for almost 1,000 m showing a steep dip to the southwest. In an enlarged area of LZ5, there is gold enrichment near the margins of the economic envelope. LZ5 includes two high-grade portions named Zone 5 Footwall and Zone 5 Hanging Wall.
Mining
LZ5 is mined from underground ramp access. The mining methods are longitudinal retreat with paste backfill, and transverse open stoping with paste or unconsolidated backfill. In its first year of operation, the mine achieved its designed production rate of 1,975 tonnes/day. Integration and pilot testing of automated mining equipment (two trucks and one scoop tram) continued in 2019.
Given the success in mining the upper portions of the LZ5 deposit (from surface to 330 m), mining activities will be extended to 480 m starting in 2020. The Company is also evaluating the potential to develop deeper portions of LZ5 (480 m to 700 m) and potentially mine portions of the neighboring Ellison property from the LZ5 underground infrastructure.
The utilization of a 4G LTE cellular network was the result of an underground communications project developed for LZ5. The system has been in use at both LZ5 and the LaRonde mine since it was completed in November 2017. The implementation of cellular technology underground – integrating both voice and digital communications in the same network – is a first in the Canadian mining industry.
In 2020, the Company will continue to test and refine automated mining techniques at LZ5 with a goal to increase the tonnage mined remotely to greater than 15% of the total tonnes mined.
Processing
The LaRonde Complex is the site of the 2,000-tonnes/day LZ5 ore processing plant (formerly used to process ore from the now-closed Lapa mine). The plant consists of a two-stage grinding circuit to reduce the granularity of the ore. The residual pulp is leached in a conventional CIL circuit to dissolve the balance of the precious metal. A carbon strip circuit recovers the gold from the carbon which is recycled to the leach circuit. LZ5 gold recovery is estimated at 92%.
In 2019, the Company was granted a revision to the Certificate of Authorization at the LaRonde Complex, which allowed for the processing of ore from LZ5 through the LaRonde mill circuit. As a result, the Company began reporting the operational parameters from both LZ5 and LaRonde on a combined basis in 2020.
Exploration
In 2020 at LZ5, drilling will be carried out to expand mineral reserves and mineral resources at depth and test other nearby satellite zones (Ellison).