Waste engine oil treatment generally goes through the following five steps：

1. Water removal: collect the waste engine oil in the oil collection tank to remove water, put it in a heating pot, stop heating after raising the temperature to 70-80°C, let it stand for about 24 hours, drain the surface water, and then Slowly raise the temperature to 120°C (when the oil temperature is close to 100°C, heat slowly to prevent the oil from boiling and overflowing) to evaporate the water. After about two hours, the oil should not be stirred, and black oily gas will emerge from the oil surface.

2. Pickling: After the oil is cooled to room temperature, slowly add sulfuric acid (concentration is about 92-98%) under stirring. The amount of acid is generally 5-7% of the oil (depending on the degree of dirtiness of the oil). After adding the acid, continue to stir for half an hour, and then let it stand for about 12 hours to drain the acid residue.

3. Alkali cleaning: Reheat the pickled engine oil to 80°C, add soda ash (Na2CO3) under stirring, stir well, let it stand for 1 hour, and then use test paper to test that it is neutral, then let it stand still More than 4 hours, drain the alkali residue.

4. Activated clay adsorption: heat the oil to 120-140°C, add activated clay (the amount is about 3-5% of the oil) under constant temperature and stirring, after adding activated clay, continue to stir for half an hour, at 110 After standing at a constant temperature at ~120°C, filter while it is hot.

5. Filtration: Use a filter to filter, and then get clear engine oil after filtering.