BY-PRODUCT MANAGEMENT
WHAT IS WASTE ROCK?
Rock that does not go to the mill is called waste rock. Some of the rock would be used as construction material for the project and the rest would be hauled to a waste rock facility. Reclamation of the facility would take place in stages throughout the life of the mine, and at closure the remaining waste rock would be contoured, covered, and revegetated as needed.
BESIDES WASTE ROCK, WHAT KIND OF BY-PRODUCTS WOULD THERE BE FROM THE MINING PROCESS? HOW WOULD THEY BE MANAGED?
Mercury Management
The rock at Donlin Creek has naturally occurring mercury that needs to be captured in the milling process. The design of the process plant utilizes state-of-the-art technology to capture mercury at four different stages in the system. The contained mercury would then be shipped off site to a regulated depository or sold to qualified users in the United States.
Acid Rock Drainage (ARD) Management
When rock containing sulfide minerals is exposed to air and water, acid can form and leach metals from the rock. Metal leaching can occur with ARD or on its own. Although much of the rock at Donlin is not acid generating, the rock that does have this potential would be managed in the waste rock facility by isolating and containing it to prevent acid generating conditions.