Improvements in and relating to a process for obtaining paraffin and highly viscous lubricating oils from lignite-tar and shale-tar

摘要

Paraffin wax and viscous lubricating-oils are separated from lignite-tar or shale tar by adding acetone, which precipates the paraffin wax. A hard wax is separated by cooling to 0 DEG C., and a further quantity of softer wax by further cooling to -20 DEG C. Lubricating-oil is obtained by removing acetone and volatile oils from the residue by treatment with superheated steam at 200-250 DEG C. or by heating in vacuo. The volatile fractions may be separated by preliminary treatment of the tar with superheated steam. The paraffin wax is refined by dissolving it in a solvent, such as the volatile fractions obtained from the tar, treating with sulphuric acid and soda lye and precipitating by addition of acetone. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the use in place of acetone of homologues such as methyl ethyl ketone and of acetic ether, and the treatment of coal tar and bituminous masses. This subject-matter does not appear in the Specification as accepted.