Greenstone Resources Ltd. constructed and operates the Santa Rosa open
-pit, heap-leach gold mine in Veraguas, Panama, which was commissioned
in 1995 at a designed capacity of 1.8 million tonnes per year. The or
e exhibits a long three-year leach cycle and requires three-stage crus
hing to achieve an average gold recovery of 74 percent. The crushing p
lant handles a high volume of clay material, and the circuit includes
a Barmac crusher. In order to control the water balance (average rainf
all is more than three meters of water per year), Greenstone developed
the means to successfully operate this low-grade gold deposit under d
ifficult operating conditions.