Sciencemadness Discussion Board

Melting steel with a DC welder

metalresearcher - 25-11-2017 at 13:21

Not exactly chemistry, but I was able to melt steel using a 60x40mm cylindrical graphite crucible as anode and a carbon rod hovering over the charge as a cathode. The temperature rises easily over 1500 C in a few minutes.

https://www.metallab.net/jwplayer/video.php?v=L2NsaXBzL01lbH...

mysteriusbhoice - 5-1-2018 at 02:15

using that same dc welder perhaps one can do some high temperature electrolysis like for producing silicon metal or aluminum
try using sand in the graphite crucible to make silicon metal and then the oxygen produced will eat whatever graphite produces the gas so make sure your anode is the electrode and not the crucible!!.

Panache - 12-5-2018 at 05:44

i was about to start a tinkering with such a setup in an effort to melt some tediously aqua regia resistant pt/pd/alumina (25/25/50) powders.
Metalresearcher, what are your thoughts on achieving the 2000+ C i was hoping for?

I have had very limited success by using an oxygen/acetelyne cutting torch flat out. By limited success i mean i proved that the way industry does it (using a plasma) is probably the only way, with a torch running over it for ten minutes my 100g (10ml) sample resolved about 10% into discrete platinum (very small beads).
Apparently Cl2 at 600C achieves dissolution also, however i have yet to rig up such an apparatus in my lounge room, choosing instead to spend time on making elemental fluorine whilst naked in the shower. that fluorine bit was a joke

coppercone - 12-5-2018 at 07:01

The commercial ones use a water cooled copper crucible and they are built like a glovebox so you can maintain the vacuum inside but still aim your stick electrode (i believe its done by hand)

I also have a piece of shit lincoln electric 225 stick welder (much prefer gas welding but also do MIG) that is suitable for this I believe.

https://www.youtube.com/watch?v=rX7PDagIq6I

[Edited on 12-5-2018 by coppercone]

fusso - 14-6-2018 at 13:29

Quote: Originally posted by mysteriusbhoice  
using that same dc welder perhaps one can do some high temperature electrolysis like for producing silicon metal or aluminum
try using sand in the graphite crucible to make silicon metal and then the oxygen produced will eat whatever graphite produces the gas so make sure your anode is the electrode and not the crucible!!.
Isn't SiO2 covalent?! How could one electrolyze molten SiO2 to make Si?!