EXTRACTION OF GOLD ORE FROM HOST ROCK
HOW WOULD THE GOLD BE EXTRACTED FROM THE ROCK?
The mineralized rock at Donlin Creek resource would require significant processing to extract the gold, including:
- crushing and grinding the ore in large grinding mills to create a fine silt-like powder
- separating the gold-bearing minerals from other material in concentrating and washing circuits
- applying heat, pressure and oxygen in an autoclave to pre-treat the ore
- dissolving the gold with cyanide solution in contained steel mixing tanks to extract it from other minerals
- gathering the dissolved gold onto activated carbon and sending the cyanide solution to a cyanide destruction circuit
- extracting the gold from the carbon in a process similar to electroplating
- refining the gold and pouring it into gold doré bars
Wet tailings resembling silt would be left over from the milling process. An engineered dam would be built to contain the tailings. It would have a synthetic liner similar to those used for city landfills. The ultimate size of the tailings storage facility would be about 1.75 miles long by 1 mile wide.