Mesa - 2-10-2013 at 10:21
Recently, in an attempt to concentrate a solution of ~30% sulphuric acid, some of the oil from the bath was accidentally spilled into the(cooled)
solution. The oil can be seen as a white cloudy suspension, but all attempts to filter it out failed.
In an unrelated project, I prepared some quite fine tungsten oxide powder by setting alight tungsten powder and allowing it it burn out.
This article;
http://pubs.acs.org/doi/abs/10.1021/ja02049a007?journalCode=...
indicates WO3 is completely unreactive toward H2SO4.
Given this, I added some of the powder to the contaminated solution and stirred it for about 15 minutes. Upon settling, the white suspension of oil
seems to have disappeared(previous shaking without addition of WO3 did not have this effect), however when the flask is swirled, the liquid dripping
down the sides of the flask act like water on an oiled surface, so I'm not sure if the contaminant has been removed.
As an aside, the yellowish tinge that developed from boiling down the H2SO4 also disappeared when the WO3 was added.