The chemical properties of silicone oil are relatively warm, but after long-term use, it will also deteriorate due to oxidation and the intrusion of foreign impurities. Since silicone oil is expensive, it should be recovered and regenerated separately.

Waste silicone oil is usually regenerated in two ways. The waste silicone oil in electrical equipment is mainly treated by adsorption refining. The waste silicone oil can be refined by contacting with silica gel, activated alumina, activated clay, activated carbon and other adsorbents. After filtering off the waste adsorbent, vacuum degassing the silicone oil at 50-110°C (for example, vacuum degassing at 95°C) or blowing nitrogen gas at 20-80°C can obtain purified regenerated silicone oil.

Another method is to treat the liquid waste silicone oil with solvent vapor, and use the dissolving effect when the solvent is condensed to dissolve and extract the impurities in the waste silicone oil, and form another liquid phase that is immiscible with the silicone oil. In this way, polychlorinated polycyclic aromatic hydrocarbons (PCBs) in waste silicone oil can be dissolved and removed. The treated silicone oil also contains a trace amount of solvent, which can be removed by vacuum drying. Usually used are hydrocarbon solvents and chlorinated hydrocarbon solvents.