Originally Posted by
rpenmanparker
The "black grime" IS the particulates, the sand and grit. The solvent and dissolved grease are not highly colored. The dark color in the grit comes from the finely divided metal particles, not the liquids. Once you filter those out, your still contaminated solvent (grease) should be light colored. And without the particulates, there will be no reason for the solvent/grease to cause wear.
No, the 'black grime' isn't the sand and grit. Those are mostly colorless. You are correct that the black color mostly comes from the metal that the sand grinding up the chain because the sand is harder than the steel. You could leach the steel away from the silicon dioxide after you've filtered and/or distilled the solvent off. The best way to remove the steel would be with hydrochloric acid...which isn't a solvent because it reacts with the iron.