- Light waste oil, its refinery is easily – applying sedimentation and filtration only. Other (primarily mechanical) methods are also used in some cases. After purification such oil can be reused.
- Dark waste oil is a result of using oil as the lubricant for car parts with high loads and high temperatures. In most cases oil darkening is caused by the presence of contaminants like oxidation products and metal particles.
Different types of oil are used in various industries. And the more machinery use oil, the bigger is the problem of waste oil – its refinery or disposal. After its purification from mechanical and other impurities which accumulate during its operation – the oil can be used more than once.
According to the degree of contamination and methods of its reclamation, there are two kinds of waste oil: