Moderating electrostatic ignition of organic/mineral animal feed mixtures

Mixing inert materials with combustible powders can mitigate electrostatic ignition risks and prevent dust explosions. In the agri-food sector, adding mineral powders to complex organic blends (premixes) is of interest for both nutritional quality and process safety. This research investigates the influence of the minerals' chemical nature and Particle Size Distribution (PSD) on the Minimum Ignition Energy (MIE) of binary mixtures to better understand the inerting effects in premixes. DL-Methionine was mixed with CaCO 3 , NaCl, and NaHCO 3 , each featuring distinct PSDs and inerting mechanisms. Ignition tests were performed using the MIKE3 apparatus following ISO/IEC 80079-20-2 standards, complemented by Differential Scanning Calorimetry, dust cloud pyrolysis tests in a modified Godbert-Greenwald oven, and gas analysis by micro gas chromatography. The mineral's PSD exhibited the most significant effect on MIE moderation, although its efficacy depended on its chemical nature. For CaCO 3 and NaCl, finer PSDs (median particle diameters of 52 and 35 μm, respectively) effectively inhibited methionine ignition due to their high thermal stability (T decomp > 900K). NaHCO 3 was the most effective inerting agent, increasing the mixture's decomposition enthalpy by 80% and releasing 30% more CO 2 into the flame zone. These findings support the implementation of inherently safer measures in premix manufacturing. • Application of the moderation principle for inherently safer animal feed mixtures. • Chemical inertants with fine particles significantly moderate ignition sensitivity. • NaHCO 3 is the most effective inertant due to its low decomposition temperature. • Efficient inerting is linked to the thermal sink effect before organic pyrolysis. • Mixing recommendations support safer powder formulation in the agri-food sector.