Gilsonite varnish from acid sludge produced by the recovery of used lubricating oil

Acid sludge produced from regeneration of used lubricating oil was chemically treated in order to convert it in to a saleable product. Investigates treatment with different inorganic formulations. Determines and discusses the optimum formulation composition. Characterizes the spectroscopic analysis, thermogravimetric and rheology behaviours, and hydrocarbon type analysis (asphaltene, oil and resin) of the extracted multicomponent resin (MCR‐1). Uses the MCR‐1 for the preparation of gilsonite varnish. The physico‐chemical properties of the latter were determined and compared with those of a standard gilsonite varnish. Concludes that treatment of acid sludge with different salt formulations provides a potentially lowest cost source of gilsonite varnish for news ink and also helps reduce an environmental problem created by re‐refining used oil.