Current guidance is based on mining and stacking an initial 22 million mt of ore grading more than 1.1 g/mt gold during the next three years, as well as continuing to leach material
currently on the pad.
The program suggests the potential to expand mineralization beyond the currently modeled pit shell and work in 2019 will focus on de-risking this potential future phase of mining including additional metallurgical characterization on heap leach material
The economic study considered a base case mining rate of 20,000 tonnes per day mining 247 million tonnes of leach material
over a life of mine of 36 years averaging 25.3 g/t silver and 5.92 g/t indium, using the three year trailing average silver price of USD13.30/oz and USD530 per kg for indium.
was considering the feasibility of recovering gold from the lower grade, heap leach material
, which contained an estimated 64,000 oz of gold.
In the Leach material
there is no evidence that R.T.C.
Additional work will assess the potential of additional mining opportunities that include a Phase 3 pit and processing of heap leach material
from all pits.
At present the grade of the dump leach material
is too low to justify crushing and heap leaching, but it does contain enough copper to warrant stockpiling as dump leach ore.
One third of this arc is dedicated for mill feed and the remainder is used for heap leach material
. The crusher operator locates the stacker over the appropriate area when operating.
Run-of-mine dump leach material
is placed on the old sulphide ore pad and leached.
Blue represents premium leach material
, pink represents high-grade leach material
, and green represents low-grade leach material
Production is apportioned into crushed and ROM heap leach material
, based on ore grade, divided roughly 75/25 by tonnage.
The mine's heap leaching facility will include 2.5M [ft.sup.2] lined area and is designed to hold about 5.35M st leach material
. A network of 4-in.-dia perforated pipes collects the pregnant leach solution from the heaps and transfers it to the solution channel, which carries it to the pregnant solution pond.