from the de-waxing of lubricating oils; it has a higher oil content than paraffin wax, Crude wax, also called petroleum wax or slack wax, is an unrefined mixture of high-melting hydrocarbons, mainly of the normal straight-chain type, still containing a fairly high percentage of oil. It is obtained by filtration (as such or after addition of a solvent) from high boiling distillates or residual oils. Slack wax is primarily obtained as by-product in the manufacture of lubricating oils. The crude wax made from distillate oils is used for the manufacture of scale wax and paraffin wax or serves as a feedstock for the manufacture of petroleum chemicals such as synthetic detergents. The crude wax made from residual oils is refined to make a range of microcrystalline waxes.