Abstract: The SO2/Air cyanide detoxification process was developed when the usual requirements were based on a relatively steady concentration of weak acid dissociable cyanide (WAD CN-) in the feed of 150 to 200 mg/L and a discharge limit of less than 50 mg/L. However, as more metallurgically complex deposits are developed, and environmental regulations become stricter, cyanide destruction demands have evolved and become more stringent. Nowadays, discharge limits below 1 mg/L WAD CN- are not uncommon, and the SO2/Air process often needs to treat feeds containing more than 600 mg/L of WAD CN-. Adding further complexity is that solutions containing elevated levels of thiocyanate (SCN-) and/or thiosalts are becoming commonplace and can negatively impact the ability to recycle process water and the capability to achieve overall site environmental compliance. This paper provides a holistic overview of the SO2/Air process, interconnections between metallurgical and environmental issues, including carbon footprint reduction and sustainability, and discusses changes in design and operations strategies needed to meet the requirements of modern gold extraction projects.