Construction of the Seabee Mine began in 1990. The Company's central milling facility was completed in late 1991 with gold production commencing in December of that year. The Seabee Operation hosts permanent facilities to support all mining operations and personnel.
The mill process consists of a three stage crushing circuit, a three stage grinding circuit, followed by cyanide leaching. The leached gold is collected in a carbon-in-pulp circuit, stripped using mild caustic and collected on stainless steel mesh cathodes by electrowinning. The product from electrowinning is refined into dore bars in a bullion furnace.
In 1997-1999 engineering exploration, development and design works for the mining-industrial complex were conducted at the deposit. The construction of the ore mining and processing plant with 130,000-150,000 tpy design capacity was started in 1998 and completed at the end of 2001.
The mine has been in operation since September, 2001 and produces approximately 75,000 ounces of gold equivalent per year. Mining is carried out and Ore goes through a crushing and grinding circuit, followed by flotation of sulfides and ultimately cyanidation of the flotation concentrate. The gold-silver precipitate is recovered by a Merrill Crowe circuit. The plant, which started up in September 2001, has a capacity of 400 tonnes per day of ore
Kupol, Russia a 3,000 tonne per day mill and will employ both open pit and underground mining methods. Construction began in 2005 and started production in late 2008. The mine is expected to output an average of 418,000 ounces of gold.
The property is about 300km from the nearest town, Bilibino, so the camp has been designed as a 'Permanent Camp'. Its size has been established at 606 people nominal but can be comfortably expanded to 656 people. The living quarters include VIP units, single-occupancy rooms, double-occupancy rooms and senior staff quarters. Because of the extreme weather conditions at Kupol, the camp also has recreational facilities for use after work such as games rooms, a gymnasium and exercise room
The mill is a conventional gold/silver cyanidation plant that incorporates a CCD thickener washing circuit and Merrill-Crowe zinc precipitation because of the high silver ore grade. Cyanide destruction is accomplished with calcium hypochlorite.
Designed to process about 3,000t of ore per day (1,100,000t per year). Run-of-mine ore is crushed in a jaw crusher and conveyed to a crushed ore storage bin. The crushed ore is ground in a SAG grinding mill followed by a ball mill. Gravity separation of free gold and silver will be carried out with a Knelson concentrator in the grinding circuit.
Although the site is connected to Bilibino via a network of roads, they are passable only between mid-December and mid-April. During the spring thaw and summer, the Kupol area is accessible only by helicopter – a 1.5-hour flight from Bilibino.
The gold/silver precipitate is dried in an oven, mixed with fluxes and then smelted in induction furnaces to produce gold/silver doré bars.
Gold and silver production began in January 2010. La Libertad Mine is scheduled to produce approximately 80,000 to 90,000 ounces of gold annually
Slurry from the mills is pumped from the cyclone feed pump box to the cyclone bank. Cyclone overflow reports to the pre-leach thickener. The thickener underflow is pumped to and flows by gravity through eleven leach tanks and five Carbon-in-Pulp (CIP) tanks.
SAG and ball mill grinding circuit, carbon-in-pulp recovery tanks, and a tailings storage facility, La Libertad Mine processing capacity of 5,500 tonnes per day.
Activated carbon is present in the five CIP tanks to adsorb the leached gold from solution. The carbon is periodically pumped counter-current to the slurry flow. Loaded carbon is taken from the first CIP tank to the Adsorption Desorption-Recovery plant where precious metals are removed.