1903. ------. [KÖLBEL, H.] (Steinkohlen-Bergwerk "Rheinpreussen"). [Purification of Hydrocarbon Oil Mixtures.] German Patent 730,853, Dec. 24, 1942 (Cl. 12 r-1.04). Chem. Abs., vol. 38, 1944, p. 860.

Oil mixtures with a boiling range of 180°-360° and composed predominantly of aliphatic oils with a similar boiling range are treated with gaseous SO₂ at ordinary pressure. Substances precipitated in consequence of this treatment are separated from the purified oil.