The chemical properties of silicone oil are relatively warm, but it will also deteriorate after long-term use due to oxidation and foreign impurities. Due to the high price of silicone oil, it should be recycled and regenerated separately.

Waste silicone oil is usually regenerated by two methods. The waste silicone oil in electrical equipment is mainly treated by adsorption refining, which can contact with silica gel, activated alumina, activated clay, activated carbon and other adsorbents. After filtering the waste adsorbent, the purified regenerated silicone oil can be obtained by vacuum degassing at 50-110 ℃ or nitrogen stripping at 20-80 ℃.

In the other method, the liquid waste silicone oil is treated with solvent vapor, and the impurities in the waste silicone oil are dissolved and extracted by the dissolving effect of solvent condensation, and another liquid phase immiscible with the silicone oil is formed. The polychlorinated polycyclic aromatic hydrocarbons (PCBs) in the waste silicone oil can be dissolved and removed by this method. The treated silicone oil also contains a small amount of solvent, which can be removed by vacuum drying. Hydrocarbon solvents and chlorinated hydrocarbon solvents are usually used.