Production of 75–150 µm and <75 µm of cerium dioxide microspheres in high yield and throughput using the internal gelation process

Hundreds of grams of calcined cerium dioxide (CeO₂) microspheres were produced using the internal gelation process with a focus on 75–150 µm and <75 µm diameter sizes. To achieve these small sizes, a modified internal gelation system was employed, which utilized a two-fluid nozzle, two static mixers for turbulent flow, and 2-ethyl-1-hexanol as the medium for gel formation at 333–338 K. This effort generated over 400 g of 75–150 µm and 300 g of <75 µm CeO₂ microspheres. The typical product yields for the 75–150 µm and <75 µm microspheres that were collected and processed were 72 and 99%, respectively, with a typical throughput of 66–73 g of CeO₂ microspheres per test, which could generate a maximum of 78.6 g of CeO₂. The higher yield of very small cerium spheres led to challenges and modifications, which are discussed in detail. As expected, when the <75 µm microspheres were targeted, losses to the system increased significantly.