Sciencemadness Discussion Board

Cleaning sintered glass filter from super tiny graphite mess.

TheMrbunGee - 15-6-2018 at 08:59

I ruined my filter with graphite particles, I was hoping to remove that stuff with hot piranha-ish solution (-ish - because I have only 10% H2O2)

It is now sitting there for a while, cooled, of course but it haven't got even a bit whiter.

Is there any other way?


Filter works fine, it is just esthetics.. And the challenge, maybe..

SWIM - 15-6-2018 at 09:13

I've heard dichromate and sulfuric acid can clean that, but I've never tried it.

TheMrbunGee - 15-6-2018 at 09:41

Ok, that's a possibility! I don't have any dichromates on me, so I will wait for confirmation, before I drive after some.

Texium - 15-6-2018 at 09:46

Quote: Originally posted by SWIM  
I've heard dichromate and sulfuric acid can clean that, but I've never tried it.
I've done it. It works quite well, though I prefer using piranha now that I have 27% peroxide since it's much safer and easier to dispose of.

TheMrbunGee - 15-6-2018 at 09:54

Okay, thank You both! :)

unionised - 15-6-2018 at 15:05

You can remove graphite using air.

You may need to heat the item to get a reaction rate you are happy with.

DavidJR - 16-6-2018 at 00:56

Quote: Originally posted by Texium (zts16)  
Quote: Originally posted by SWIM  
I've heard dichromate and sulfuric acid can clean that, but I've never tried it.
I've done it. It works quite well, though I prefer using piranha now that I have 27% peroxide since it's much safer and easier to dispose of.


Easier to dispose of, yes certainly. But it’s not safer. Far from it. There have been numerous serious lab accidents resulting from the use of piranha solution.

I’ve had luck removing activated carbon powder from frits using piranha made with drain cleaner acid and 12% hydrogen peroxide. I assume graphite powder is more difficult to remove due to surface area to mass ratio, but it should still work slowly I think.

One good think about chromic acid is that you can reuse it indefinitely - piranha goes off pretty quickly and must be prepared immediately before use.