LOI (Loss on Ignition)

Notas

Loss on Ignition (LOI) represents the portion of a raw ceramic material's mass that is released as volatile gases during the thermal decomposition process. These substances, which may include chemically bound water, carbon dioxide, sulfur trioxide, or elemental carbon, are driven off while the material is being fired. Because these components exit the kiln atmosphere, they are not present in the final solidified glaze and therefore do not constitute part of the fired oxide chemistry. In the context of material analysis, the LOI is critical for determining the accurate formula weight of raw ingredients. To calculate this, the combined weight of the residual, stable oxides is divided by the percentage of non-volatile material (the total mass minus the LOI percentage). Consequently, while LOI is essential for calculating the batch recipe during the formulation stage, it is excluded from the final chemical profile of the matured glaze.