Officials at Agnico Eagle Mines Ltd. have reported that commissioning is in progress at their La India gold mine in Sonora, Mexico. Mining and pad loading are under way, as initial leaching was expected to begin in October while commercial production is anticipated in Q1 2014; capital expenditures remain on budget at $157.6 million.
La India lies 70 km northwest of Agnico Eagle’s Pinos Altos mine. The company acquired the project, along with a 56,000-hectare land position, on the Mulatos gold belt, in Q4 2011 when it acquired Grayd Resources. Design, permitting, construction and start-up were completed within 22 months of acquisition.
La India is an open-pit, heap leach mine, with a stripping ratio of approximately one-to-one. The mining rate is expected to be approximately 16,000 metric tons per day (mt/d), using Cat 777 haul trucks and 992 loaders, which also is the equipment used at Agnico Eagle’s Pinos Altos and Creston Mascota operations.
Ore will undergo three-stage crushing to minus 19 mm through a crushing circuit that has room for expansion. The leach pad will be constructed in two phases and will have a capacity of up to 50 million dry mt.
The La India gold adsorption facility consists of two parallel trains of five 3.5-mt carbon adsorption columns and a Zadra strip, followed by electrowinning. The plant is designed to process leach flows up to 6 million dry mt/y of ore; leach recovery is estimated at 80% at a 90-day leach time.
Production is expected to average approximately 90,000 oz annually at an average total cash cost of approximately $500/oz. Production for 2014 and 2015 is estimated at 40,000 oz and 81,000 oz, respectively.
Current reserves total 33.5 million mt of ore grading at 0.72 g/mt gold for 776,000 contained oz; metallurgical testing continues on the La India sulphides and on ores from the Tarachi deposit 10 km north of La India.