Centerra Gold Inc.

Processing Improvements and Upgrades

The Mount Milligan Mine processing plant continues to operate at its nameplate capacity of 62,500 tpd. Upgrades to the grinding and flotation circuits in 2029 are expected to increase the capacity to a rate of 66,300 tpd, subject to test work validation.

To support the increase in plant capacity, the ball mills will need to be modified to have grate discharge. The ball mill charge will increase to 31.5%, or as required to achieve the full grinding motor capacity. The current total installed ball mill power of 26 MW is not sufficient to accommodate the change to grate discharges. Two new 7.5 MW (10,058 Hp) motors are required for each ball mill, for an increased total installed ball mill power of 30 MW.

The plant upgrades planned for 2029 require the introduction of a rougher-scalper flotation circuit to expand the rougher flotation circuit capacity. This change includes one SC-200 StackCells® to both trains, with each cell having one 112 kW (150 Hp) motor and a volume of 65 cubic metres into each rougher line. The total increased volume of 130 cubic metres is expected to add an equivalent of 400 cubic metres with respect to retention time kinetics. There will be associated changes to the piping in the rougher flotation circuit to accommodate the new cells.

To enhance flotation performance, the Mount Milligan Mine is implementing FlotIQ, an advanced analytics platform designed to optimize flotation control through real-time data processing and machine learning. FlotIQ utilizes froth imaging and dynamic process feedback to actively adjust cell pull rates and reagent dosing, improving circuit responsiveness and metallurgical outcomes. This is expected to contribute to more stable operation and improved recovery (approximately 0.8% for copper and gold) and consistency across varying feed conditions.

For information on the Mount Milligan Mine mineral reserves and mineral resources, see*“Mineral Reserves and Resources”* starting on page 16.