The Goldex Mine, operated by Agnico Eagle, processes ore through a conventional grinding and flotation flow sheet. While the plant layout is relatively straightforward, site conditions presented unique control challenges, particularly in managing semi autogenous grinding (SAG) mill stability and achieving consistent flotation performance under variable operating conditions. Ore hardness fluctuations and changes in feed characteristics frequently impacted circuit stability, creating challenges for operators attempting to maintain optimal throughput and recovery. To address these issues, Advanced Process Control systems were implemented on both the grinding and flotation circuits. The grinding Advanced Process Control focused on preventing SAG overloads by dynamically adjusting SAG feed rate and SAG feed density in response to changing ore characteristics and Mill Load. This reduced the frequency and severity of overload conditions, minimised operator intervention, and allowed for a more stable and consistent operation while maximising mill utilisation. The flotation circuit presented a different challenge: the site lacked online grade measurement, limiting direct insight into grade or recovery. As a result, the flotation Advanced Process Control was developed around a strategy based on managing concentrate flow rates used as a proxy for mass pull. This approach enabled automated control of reagent dosing and cell pull rates throughout the circuit, stabilising froth behaviour and maintaining operating conditions aligned with recovery objectives. By continuously responding to process disturbances, the system helped reduce variability and improve overall circuit performance. The results of the Advanced Process Control implementation were substantial. Flotation performance saw improvements in stability and recovery, while grinding became more robust and resilient to ore variability. In addition to metallurgical improvements, operators benefited from greater process consistency and reduced time spent responding to upset conditions. This paper highlights the control strategies deployed for both circuits, the challenges posed by limited instrumentation, and the operational improvements achieved through Advanced Process Control, demonstrating the value of advanced control technologies in maximising plant performance.