Abstract: In the recovery of regenerated mineral and synthetic oils from blackish dirty lubricating or industrial oils, a quaternary ammonium salt or mixture of salts is added to the dirty oil and the mixture is subjected to agitation. The agitated mixture is next subjected to a decanting operation making it possible to recover, as the upper supernatant fraction, an oil exhibiting approximately the same characteristics as a new starting oil useful for automotive engines, transmissions and differentials, as a lubricant for machine tools, useful in transformers and other electric and electropneumatic devices and also useful as a hydraulic fluid.

Abstract: Water, polluted with hydrocarbons and similar pollutants in which separation occurs into an upper layer, rich in hydrocarbons and residues, and a lower layer consisting of a hydrocarbon suspension or emulsion in water, is treated to remove the pollutants from the water. The upper layer is treated with quaternary ammonium salts to separate the heavy residue from a clear (or light-colored) supernatant layer, analogous to fuel oil and reusable; the lower layer is then treated with a mixture of a polyose (starch, for example) and a coagulant (for example, ordinary alum) to obtain a practically pure water. This treatment may be applied to water containing oil products and, in particular, water collected from degreasing and dewaxing plants.