The St Ives Gold Mine processing plant is designed to process 4.2 million tonnes per annum (Mt/a) of predominantly fresh ores at a nominal gold head grade of 2 to 5 g/t. Over time, stockpiles containing approximately 2.5 Mt of clay, oxide, and transitional ores have accumulated, with the prioritisation of treating higher-grade fresh open pit or underground ores. Historically, the plant feed blend contained approximately 10 per cent oxide ores. The clay/oxide ores at St Ives are relatively ‘sticky’ and have high viscosity when finely ground in slurry form. The recent reduction in the availability of open pit mined ores has resulted in the need to process larger volumes of clay/oxide stockpiles (including recently mined shallow open pits containing oxide/clay ore, such as Delta Island), requiring blending up to 30 per cent. In the fiscal year 2023, St Ives processed more than 1 Mt of oxide/clay material, with an additional 2.5 Mt planned for processing in 2024 and 2025. The treatment of oxide/clay ores caused significant challenges with the processing plant, including material handling issues on the run-of-mine (ROM) pads, haulage, and crushing; and performance issues with the single-stage SAG mill, trash screens, slurry pumps, and tailings thickener. In response, the St Ives team has implemented a series of operational adjustments, circuit and equipment upgrades and modifications, test work programs, and milling circuit surveys and studies to ensure that the plant maintains its production targets while processing the higher proportion of oxide/clay ores in the feed blend. This paper discusses St Ives’ operational challenges in processing the oxide/clay stockpiled ore and provides an overview of the successful strategies implemented and the lessons learned.