Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Chemical Removal of Copper from Graphite Gouging Rods
Hazard to Others

Posts: 182
Registered: 29-3-2013
Member Is Offline

Mood: No Mood

[*] posted on 1-8-2019 at 17:23
Chemical Removal of Copper from Graphite Gouging Rods

Hi all,

Looking for some ideas to remove the copper cladding from graphite gouging rods. Obviously there is mechanical removal which I've found to be messy and very time consuming. I currently have a few rods soaking in a dilute HCl and H2O2 solution, seems to be working okay. Ferric chloride might work but will probably also contaminate the graphite making it unfavorable for some uses.

I just want to get some input on methods of removal that wont contaminate or degrade the graphite. This is for a video series, so I want to put multiple methods out there that I may not have thought of.

View user's profile Visit user's homepage View All Posts By User

Posts: 5641
Registered: 4-10-2014
Location: Oz
Member Is Offline

Mood: d jolly / dt > 0

[*] posted on 1-8-2019 at 22:58

You would want to rotate the rods though.

View user's profile View All Posts By User
International Hazard

Posts: 1213
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline

Mood: I'm a maddo scientisto!!!

[*] posted on 2-8-2019 at 00:44

being copper dilute nitric acid looks obvious.
then there's the microwave assisted carbon and hydrogen peroxide, acetic acid and a pinch of salt method (:D)

feel free to correct my grammar, or any mistakes i make

If you are looking for chemicals check this out: [For Sale]300 chemicals (rare & unusual)
View user's profile View All Posts By User
National Hazard

Posts: 283
Registered: 12-4-2019
Location: The Known Universe
Member Is Offline

Mood: no mood is a good mood

[*] posted on 2-8-2019 at 01:26

i did this before ,best way is Electrolysis in dil. sulfuric acid like 5%. use copper cathode so no waste is generated let it run till all copper is plated on the wire. it will not degrade the graphite if you used low current (1-2A)
View user's profile View All Posts By User
National Hazard

Posts: 319
Registered: 22-10-2016
Member Is Offline

Mood: No Mood

[*] posted on 2-8-2019 at 04:47

1M H2SO4 + some H2O2 should work very well.
CuCl2/HCl should work well too, but might leave some CuCl residue.

Both these methods are used for etching copper on printed circuit boards.

If you have nitric acid on hand, it will work even better.
View user's profile View All Posts By User
Radically Dubious

Posts: 2999
Registered: 7-5-2011
Member Is Offline

Mood: No Mood

[*] posted on 2-8-2019 at 05:23

Commercial leaching of copper is accomplished with ammonia, ammonium carbonate, and air which is a mixed reaction involving some electrochemisty (and so, as an electrolyte, you might want to add a pinch of sea salt as Ubya suggests, a smart guy, but he apparently uses his microwave for everything, so I would trust this reference more and also this source, where the entire text is available for free at: ).

Unfortunately, the cited provided chemistry is even a little more complex with a mention of a minor secondary reaction, as the O2/Cu reaction complexed with NH3 is akin to a metal/air battery forming instrumental solvated electrons (as sourced from copper, so it is correct to claim that copper is catalytic to the oxidation of ammonia to nitrite from air). The latter e-(aq), I would surmise, with O2 may introduce the superoxide radical, and with H+, the hydrogen atom radical, which can interact with NH3 forming •NH2 radical, further interacting with O2 as follows:

•NH2 + O2 → NH2O2• (aminylperoxyl radical unstable) → NO + H2O

As a reference, see "On the aqueous reactions of the aminyl radical with molecular oxygen and the superoxide anion", Page 24, Table 2.1 at .

where the NO is a precursor to nitrite, and in particular NH4NO2. The latter has the annoying property of suddenly based on pH, of rapidly releasing volumes of N2 gas, which will cause leakage and even breakage of sealed reaction vessels (as I have experienced).

Some bottom line, don't tightly seal your reaction vessel (and I would recommend avoiding any skin contact with the solution due to possible toxic ammonium nitrite presence), because the cited minor secondary reaction (which creates NH4NO2) may have consequences.

[Edited on 2-8-2019 by AJKOER]
View user's profile View All Posts By User

  Go To Top