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US 4,021,333 AGranted
Method of rerefining oil by distillation and extraction
AssigneeThe Lubrizol Corporation
InventorsEmile Najib Habiby, Richard William Jahnke
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Abstract
Used oil is rerefined by distilling it to remove a volatile forecut followed by a fraction of lubricating viscosity; the latter is then extracted with an immiscible liquid extractant to remove impurities. As optional preliminary steps, the oil may be diluted with a volatile diluent and insoluble impurities removed therefrom, and heated with an aqueous solution of a strongly alkaline material to concentrate metallic constituents (such as metal-containing additives) in a solid sludge.
Claims15
A method of recovering oil of lubricating viscosity from used oil which comprises the steps of:
- (A) Distilling said used oil to remove therefrom a forecut having a viscosity substantially less than that of lubricating oil and a flash point (Tag or Pensky-Martens method) less than 121.degree. C.;
- (b) continuing the distillation to recover a distillate having substantially the viscosity of lubricating oil;
- (C) Extracting impurities from the distillate of step B with an organic liquid extractant which is substantially immiscible with said distillate;
- and
- (D) Removing said organic liquid and impurities dissolved therein from said distillate.
2 more elements
Dependencies are inferred from the claim text.