Williams is an underground and open-pit mining operation, owned and operated by Barrick Gold Corporation.
Williams is located in northwestern Ontario, Canada, approximately 350 kilometers east of the city of Thunder
Bay.
Production at Williams began in mid-1985 from the A Zone open-pit located at the east-end of the property. Soon
after, ore was mined from the underground in the same area to sustain an initial mining rate of 3,000 tonnes per
day. The completion of the main shaft, the B Zone infrastructure, and a mill expansion program in 1988
facilitated an increase to 6,300 tonnes per day. The closing of the David Bell mill in 1999 and increased
production from the C Zone pit brought the mill to a throughput of 10,000 tonnes per day by the end of 2006.
Underground mineral reserves at Williams are projected to sustain the underground mine operations until 2021 at
an average production rate of approximately 3,600 tonnes per day, while open-pit mineral reserves at Williams
have the potential to support operations until 2027 at rates ranging from 5,000 tonnes per day to 6,000 tonnes
per day.
The open-pit operation is a typical truck-and-loader/hydraulic shovel operation. Underground stoping comprises
two methods, the longhole and Alimak methods.
The processing plant consists of grinding, cyanide leaching, carbon-in-pulp (CIP), carbon stripping and
reactivation, electrowinning, and refining. The mill has two parallel grinding circuits each consisting of a
6,000 tonne coarse ore bin, a semi-autogenous grinding (SAG) mill, and a ball mill that is operated in closed
circuit with hydrocyclones.