The benfication process at the Mill Complex consists of:
- Crushing: Crush ore grade material from the mine to between five and seven inches in size.
- Grinding: Feed coarse ore stockpile onto conveyor belts and deliver to a grinding mill where it is mixed with water; five inch steel balls grind the ore to create a coarse slurry.
- Flotation and Filtration: The flotation circuit is made up of a series of large tanks, or cells, with each cell containing an agitator and air blower.
- Concentration: Two concentrates are produced from the ore – a lead concentrate and zinc concentrate, with the gold and silver found mostly in the lead concentrate.