Abstract: The refining of industrial waste lubricating oil was investigated with N-methyl-2-pyrrolidone (NMP) and Duo-solvent (ethanolamine and NMP) as solvents, respectively. The preferred refining process is duo-solvent refining under 70 ℃ with 5% ethanolamine, under these conditions the total oil yield was 89.85%. The physical properties of recycled oil is listed as follows: viscosity（40 ℃） 30.89 mm²•s^-1, viscosity（100 ℃） 5.6 mm²•s^-1, viscosity index 120.4, refractive index 1.450, Color 2.0, freezing point -28.8 ℃, flash point 219.6 ℃ and sulfur content 0.057%.

Key words: Waste lubricating oil, Duo-solvent refining, NMP refining

摘要： 将乙醇胺和N-甲基吡咯烷酮（NMP）配成双溶剂，采用NMP精制和双溶剂精制两种方法对工业废润滑油进行研究。结果表明，双溶剂精制的适宜工艺条件是精制温度为70 ℃，乙醇胺加入的体积分数为5%。在适宜条件下，双溶剂Ⅱ(V(乙醇胺)∶V(NMP)=5∶95)精制油品收率为89.85%，40 ℃下粘度为30.89 mm²•s^-1，100 ℃下粘度为5.60 mm²•s^-1，粘度指数为120.4，25 ℃下折光率为1.450，色度为2.0，凝点为-28.8 ℃，闪点为219.6 ℃，硫质量分数为0.057%。

关键词: 废润滑油, 双溶剂精制, NMP精制