A method of recovering precious metal values from refractory sulfide ores
is provided. The method includes the steps of separating clays and fines
from a crushed refractory sulfide ore, forming a heap from the refractory
sulfide ore, producing a concentrate of refractory sulfide minerals from
the separated fines and adding the concentrate to the heap, bioleaching
the heap to thereby oxidize iron sulfides contained therein, and
hydrometallurgically treating the bioleached ore to recover precious
metal values contained therein.