Recovery of nitrogen bases from mineral oils

Claim 1

A PROCESS FOR SEPARATING ORGANIC NITROGEN BASES FROM A FEED MIXTURE COMPRISING (1) A MAJOR PROPORTION OF HYDROCARBONS (2) AT LEAST ABOUT 10% BY VOLUME OF AROMATIC HYDROCARBONS AND (3) A MINOR PROPORTION ABOVE ABOUT 0.2% BY VOLUME OF ORGANIC NITROGEN BASES, WHICH COMPRISES EXTRACTING SAID MIXTURE WITH A QUANTITY OF A SUBSTANTIALLY NEUTRAL SOLVENT COMPRISING A MAJOR PROPORTION OF AN ALIPAHTIC HYDROXY COMPOUND, SAID QUANTITY OF SOLVENT BEING SUFFICIENT TO EXTRACT AN APPRECIABLE, SIGNIFICANT PROPORTION OF SAID NITROGEN BASES BUT INSUFFICIENT TO EXTRACT MORE THAN A MINOR PROPORTION OF SAID AROMATIC HYDROCARBONS, THE PROPORTION OF ORIGINAL NITROGEN BASES EXTRACTED BEING LARGER THAN THE PROPORTION OF ORIGINAL AROMATIC HYDROCARBONS EXTRACTED, THEREBY FORMING A NITROGEN-BASE-RICH EXTRACT, AND A RAFFINATE HAVING A REDUCED NITROGEN BASE CONTENT BUT STILL CONTAINING A MAJOR PROPORTION OF THE ORIGINAL AROMATIC HYDROCARBONS, AND RECOVERING NITROGEN BASES FROM SAID EXTRACT.