Mineral oil comes from refining petroleum through a process of atmospheric distillation of crude oil.
Mineral oils are notable for their viscosity, and their ability to dissipate heat. Mineral oil, as it currently comes out of the earth's crust, is a more or less dense fluid table of a Its color can vary from light yellow to black, and it gives off a characteristic petroleum odour. It often appears to carry sand and water.
Mineral oil is the most abundant group of lubricants and is divided into paraffinic and naphthenic oils.
Paraffinic oils are characterized by the CnH(2n+2) chain. They are relatively stable at high temperatures, contain a large proportion of dissolved paraffin and therefore tend to solidify at higher temperatures than naphthenic oils.
Naphthenic oils are characterized by the formula CnHC2rO and often contain a high proportion of asphalt. They tend to be more stable than paraffinic oils at high temperatures and contain little or no paraffin and therefore remain liquid at low temperatures. The viscosity of naphthenic oils varies more with temperature change than its paraffinic counterpart and they are generally considered to have lesser performance at temperatures higher that 65°C, although modern refining methods have helped to reduce this performance gap.
From a lubrication viewpoint, asphaltic oils can be considered identical to naphthenic oils and in practice these names are used interchangeably.
Mineral oil as mentioned above is petroleum based. This indicates that it is impure and has in its composition mixtures of various sizes of hydrocarbon molecules, sulfur, paraffins, salts and metals. Therefore heat and oxidation are the main reasons for its decomposition.
Mineral oil over time decreases its ability to do the job, which is to lubricate surfaces to prevent accidental friction and transfer heat away from the area being lubricated.
Since mineral oils are cheap, they are widely used in machinery lubrication. Mainly in engines.
The uses and applications of mineral oil are very wide, as they are used in different industries, for example:
They are not recommended for extreme conditions or critical equipment, given their composition this type of oil does not resist extreme temperatures, high loads or high speeds.
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