Historically, companies have produced ore from two locations on the Arista mine, the open pit mine and the underground mine. The open pit mineralization is considered low sulfidation, epithermal mineralization primarily of gold with some silver and no base metals. In 2021, mining activities were completed in the open pit, and it will now become the site for filtered dry stack tailings deposition. The Arista underground mine is considered intermediate epithermal mineralization of gold, silver, copper, lead, and zinc. The host rock in the Arista vein system is primarily andesite.
Conventional drill and blast methods are used to extract the Mineral Resources from the Arista mine at the Aguila project.
There are two main mining methods used in the Arista mine: 1) overhand mechanized cut and fill (CAF) and 2) long-hole open stoping (LHOS) with delayed fill. Paste fill, cemented rock fill and uncemented rock fill are applied to long-hole stoping areas in order to increase extraction levels (removal of rib pillars), CAF uses uncemented rock fill as a backfill method.
For the stoping methods, a crosscut from the main ramp intersects the vein, from which an initial drift is excavated perpendicular in both directions along the strike length of the vein. Once the economic limits of the vein have been reached the production cycle starts.
Overhand Mechanized Cut and Fill (CAF)
A CAF stope is started by means of a short (40 to 60 meter) nega ........
