Abstract :
Mineral oils have been used as insulating liquids for more than 100 years starting in a transformer application. Today´s mineral oil products are of course very different from the original product but the sources are still the same and partly the refining methods. The availability is good and compared with synthetic and other products life cycle analysis are very positive. What have changed are the requirements and the refining techniques to achieve desired properties. These refining techniques are described as is the oil chemistry
