PROCEDE DE PURIFICATION DES HUILES DE LUBRIGIAGE USEES

摘要

A process for the production of an essentially ash-free oil stock from a lubricating oil containing ash-forming components comprising (a) contacting said lubricating oil with an aqueous ammonium salt treating agent; (b) removing a major portion of the water from the mixture resulting from combining said aqueous solution and said lubricating oil; (c) heating at least a portion of the product resulting from step (b) at a temperature in the range of about 320 DEG to about 420 DEG C. for a period of time sufficient to decompose at least a portion of any ammonium salts of sulfonic acid and dialkyldithiophosphoric acid that are contained therein; (d) cooling the product from step (c) to a temperature in the range of about 150 DEG to about 180 DEG C.; and (e) separating the solids from the product of step (d), optionally with subsequent hydrotreating and stripping of the oil thus obtained.