Hello, I've been recently reading about tungsten carbide and I read that it is super strong, temperature resistant and it is electrically conductive,
as well, and it does have some decent chemical resistance , so I wonder if it would be suitable for aqueous electrolysis anode, ano thoughts or
experiences to share before I consider shelling some cash on some tungsten carbide drill bits?
I took a look in the web and the forum(used the search function for "tungsten carbide") and nothing came up Rainwater - 27-8-2024 at 17:31
A W anode will dissolve in most aqueous solutions.
But if your talking about molten salt electrolysis you have a winner.
Corrosion is still an issue in my NaCl to Na cell, but only above the liquid level. And it is not as bad as stainless steel or raw iron.
[Edited on 28-8-2024 by Rainwater]j_sum1 - 27-8-2024 at 17:45
Tungsten is not tungsten carbide.
I am not even sure how electrically conductive tungsten carbide is.
As with most things electrolysis, a simple experiment will give you the answers you need.Fulmen - 27-8-2024 at 22:52
According to Wikipedia it has a resistivity of 0.2 μΩ·m, so comparable to steel or lead. That's pretty decent for a ceramic... bnull - 28-8-2024 at 05:36
WC is attacked by acids in the presence of oxidisers. If the acid happens to be an oxidiser, that may mess things up.EF2000 - 28-8-2024 at 08:54
Isn't the tungsten carbide in tools mostly WC composite with cobalt as a binder? It's called cemented carbide (or Pobedit) and consists of about 90%
WC powder and 10% binder. Tools from pure WC would be rather brittle.
I guess its chemical resistance is closer to that of cobalt.bnull - 28-8-2024 at 09:29
Quote:
Isn't the tungsten carbide in tools mostly WC composite with cobalt as a binder?
Yep. That was one of the issues here. It would slowly crumble (WC) and dissolve (cobalt).yobbo II - 30-8-2024 at 11:05
"Tungsten Carbide" drill bits only contain two lumps of TC at the drill tip and are used to drill masonry AFAIF.
The link below shows a Tungsten carbide rod. It is 10% cobalt. I think thats 10% Cobalt, 90% W Carbide AFAIK.
Don't know what they will do in a Chlorate cell. If 10% Cobalt they will dissolve IMO.
Stuff used for heating elements would be an intersting experiment. Molybdenium Disilicide. Also called super Kanthal Ceramic heating elements. Kanthal
are the makers. There are others.
I guy from Ukraine is selling some at the moment on ebay here:
Hello fine people, first of all, thanks for everyone's reply, your imput is much appreciated .
second of all, I guess I'll be back to the drawing boar with this one since:
1 - it has cobalt as a binder as pointed by some of you
2 - the piece is so small (at the tip of tools) it is not worth my time
anyhow, thanks for at least entertaining my poor though process, since a bit more attention in my research would have already revealed that.yobbo II - 31-8-2024 at 08:35
So it's on to moly. Disilicide then!
Yobyobbo II - 31-8-2024 at 14:01
Attached is a paper that discusses what will or might make a suitable anode material.
It's the only paper I have ever seen that touches this subject.
It would appear that the type of conduction that the material possesses will dictate (to an extent) if it's going to be a possible successful
candidate.
Ionic conduction will give a material that will erode.
So we want electronic conduction, which can be either N type or P type.
P type is what you want for anodes (I think). (that is what I am taking from the paper anyways)
I am open to correction!
It's from Denki Kagaku 1979
I ran the japanese part of the paper through Google translate and got this:
(the rest is english)
_______________________________________________________
K. lotyrkin's paper first lists the conditions that an anode material must meet, and then develops various anodes based on these conditions.
Comparing and considering different materials. Next, we will discuss the historical development of salt electrolysis, a comparison between graphite
and metal anodes (DSA), and talk about your own experiences.
The research moved on to electrochemical research on metal oxide electrodes, especially DSA, as well as electrochemical research using
chromatographies in chlorine gas.
We measured the amount of RuO depleted using high-sensitivity activation analysis, and discussed the correlation between these three factors
DSA is Dr. Beer in the Netherlands, Ozonzio de Nora Impianti Electrochimici in Italy, and Diamond in the United States.
It was developed in cooperation with Shamr・ck and successfully put into practical use as an electrode for salt electrolysis in 1966. This electrode
is hard to wear out and
It has the excellent characteristics of low chlorine overvoltage and low oxygen evolution reaction, which is a side reaction.
It has replaced graphite anodes and is being applied to other fields.
Academician Ya. M. Kolotyrkin is the director of the Karpov Institute of Physical Chemistry and is a research scientist who specializes in corrosion,
especially corrosion.
He is well known for his electrochemical studies of passive films, and all of his research has its basis in electrochemical measurements.
Recently, he has achieved remarkable results in research on pitting corrosion, selective dissolution of alloys, and the resulting changes in the
composition of the surface layer.
Ru. Simultaneous determination of various eluted metals using high-sensitivity activation analysis method (7-spectral method) and analysis of surface
layer composition using EPMA
By using the results to interpret the electrochemical polarization behavior, we mainly aim to elucidate the mechanism of local corrosion and changes
in the surface state of the alloy.
I'm keeping an eye on it.
In this paper, V. makes full use of these instrumental analyzes and electrochemical methods to investigate the corrosion rate of RuO during
electrolysis.
We quantitatively measured the consumption rate. Furthermore, we found that the consumption rate differs depending on the mixing ratio of RuO and Tio.
It was concluded that TiO has the dual effect of reducing the corrosion rate and suppressing the oxygen evolution reaction. Also, Spinel Cobalt
Research results using oxide (Co, 0,) as the anode material are also shown.
As described above, this paper draws on the experience of corrosion research to date to investigate the effects of metal oxide electrodes on their
wear and reaction selectivity.
This perspective not only shows new knowledge about metal oxide electrodes, but also provides information on future developments in anode materials.
(Shiro Yoshizawa, Faculty of Engineering, Kyoto University)
