Mineral oil defoamers are classical oil-based antifoaming agents composed of refined mineral oil as the carrier, combined with hydrophobic particles such as silica and waxes. Their defoaming mechanism relies on the low surface tension mineral oil rapidly spreading across foam film surfaces, while the carried hydrophobic particles act as active centers to directly puncture bubble membranes, working synergistically to accelerate foam collapse. These defoamers demonstrate excellent chemical inertness and thermal stability, showing exceptional compatibility with oil-based systems while avoiding silicone contamination issues. They are widely used in industrial applications including lubricants, metalworking fluids, petroleum refining, oil-based coatings, and adhesives, effectively controlling process-generated foam to enhance product performance and ensure smooth operations. Although their defoaming efficiency is lower than silicone-based products, their significant cost advantages maintain their important application value in scenarios not requiring extreme defoaming performance.