Anhydrous Pre-Fused Fluxes: High Purity Fluxes for Fusion Sample Preparation XRF, AA & ICP analylitical methods. Fluxite Fusion Fluxes and Additives are of high density, and granular at the partial size level. They offer controlled particle size distribution of 100 to 500 µm with exceptional purity. Fluxite is free flowing and ideal to use with automatic weighing systems. LOI is less than 0.05%. Oxidants and non wetting agents are also available within this category.