Sciencemadness Discussion Board

Extract Zr from ZrO2 using Mg?

Conure - 23-3-2024 at 15:27

I saw a youtube video claiming that Zr can be extracted from ZrO2 using Mg.
https://youtu.be/14grJgRldiU?si=MxROatP2l4d5Lk7s

I have never heard of this process before so I wonder if it's too good to be true. I tested it myself and it seemed to work. I did get a weak reaction.

This made me think of a way to get Zr:
1. Burn ZrO2 with excess Mg in a closed container. Let it cool.
2. Put the products in a beaker with HCl. This will turn MgO and Mg into MgCl2 which dissolves in water. Zr remains unchanged in HCl.
3. Neutralize the acid with NaHCO3.
4. Filter the mixture with coffe filter. Leaving Zr in the filter and MgCl2 in the bottle below.

Any problem?





[Edited on 24-3-2024 by Conure]

Admagistr - 23-3-2024 at 16:22

Quote: Originally posted by Conure  
I saw a youtube video claiming that Zr can be extracted from ZrO2 using Mg. I have never heard of this process before so I wonder if it's too good to be true. I tested it myself and it seemed to work. I did get a weak reaction.

This made me think of a way to get Zr:
1. Burn ZrO2 with excess Mg in a closed container. Let it cool.
2. Put the products in a beaker with HCl. This will turn MgO and Mg into MgCl2 which dissolves in water. Zr remains unchanged in HCl.
3. Neutralize the acid with NaHCO3.
4. Filter the mixture with coffe filter. Leaving Zr in the filter and MgCl2 in the bottle below.

Any problem?

Mg is a strong reducing agent, it should do the trick! I'm just wondering if zirconium forms some kind of alloy with magnesium, or an intermetallic compound that doesn't dissolve in HCl, or dissolves very difficult only when boiling, that could be a problem with this method...?


Rainwater - 23-3-2024 at 17:07

It might be cheaper to use electrolysis to reduce zinc back to the metal. Zinc is much cheaper than magnesium.

bnull - 23-3-2024 at 17:55

Quote: Originally posted by Admagistr  
I'm just wondering if zirconium forms some kind of alloy with magnesium, or an intermetallic compound that doesn't dissolve in HCl, or dissolves very difficult only when boiling, that could be a problem with this method...?

It may be worse, with the alloy dissolving in HCL. It is one of the few acids that attack zirconium.

Admagistr - 23-3-2024 at 19:17

Quote: Originally posted by bnull  
Quote: Originally posted by Admagistr  
I'm just wondering if zirconium forms some kind of alloy with magnesium, or an intermetallic compound that doesn't dissolve in HCl, or dissolves very difficult only when boiling, that could be a problem with this method...?

It may be worse, with the alloy dissolving in HCL. It is one of the few acids that attack zirconium.


You're right about Zr not being very resistant to HCl! I was mistaken that the author claimed that Zr does not dissolve in HCl...So it cannot be cleaned without restrictions with hydrochloric acid...Neither can H2SO4. Maybe some weak organic acid like citric acid could be used?
However, this paper allows the use of HCl under specified conditions:
https://www.titanmf.com/wp-content/uploads/docs/Zirconium-in...


[Edited on 24-3-2024 by Admagistr]

[Edited on 24-3-2024 by Admagistr]

Conure - 24-3-2024 at 02:29

You people are saying Zr is sensitive to HCl?

According to these articles it's not.

https://www.totalmateria.com/page.aspx?ID=CheckArticle&s...
"Zirconium has outstanding resistance to hydrochloric acid, sulfuric acid, organic acids, and alkaline media such as sodium hydroxide. Its resistance to nitric acid is equaled only by the noble metals such as tantalum. The most common application areas for cast zirconium equipment are in hydrochloric acid, sulfuric acid, and hot organic acids. Zirconium shows excellent corrosion resistance to all concentrations of hydrochloric acid even at temperatures exceeding the normal boiling point. However, zirconium is not resistant to hydrochloric acid containing oxidizing species such as cupric chloride, ferric chloride, or wet chlorine. "

https://www.sciencedirect.com/topics/chemistry/zirconium
"In the absence of oxidizing conditions, zirconium is one of the most corrosion resistant metals to hydrochloric acid."

https://www.chemicalprocessing.com/processing-equipment/desi...
"Zirconium offers excellent resistance to many strong acids, including nitric, hydrochloric and 70 percent concentrated sulfuric acid, as well as most organic acids. It also resists most chloride salt solutions and will stand up to alkaline environments.

However, the metal is vulnerable to attack by hydrofluoric acid, acidic oxidizing chloride solutions such as ferric or cupric chloride solutions, red fuming nitric acid, concentrated sulfuric acid, aqua regia and wet chlorine environments."

[Edited on 24-3-2024 by Conure]

[Edited on 24-3-2024 by Conure]

[Edited on 24-3-2024 by Conure]

bnull - 24-3-2024 at 05:56

Quote: Originally posted by Conure  
You people are saying Zr is sensitive to HCl?

I was, karl. But I checked Brauer some minutes ago and no, zirconium is resistant as long as the solution has no iron(III), copper(II), fluoride, dissolved chlorine, or other oxidisers. And yes, it is attacked by hydrofluoric acid (my memory is not as good as it used to be).

Anyway. The product of the reaction will be most probably an impure alloy of zirconium and magnesium with some oxygen (call it ZrxMgyOz).

Your step (2) may or may not work: if the reaction (1) is not complete, it's ZrxMgyOz plus ZrO2 that will be in the filtrate.

You can skip step (3) because you're interested in the filtrate, not the solution, right? Don't neutralise the solution, just wash the solids with water after filtration.

I don't know how you can separate ZrxMgyOz from ZrO2. If the proportion of magnesium is low enough, the densities will be too close to try fusion.

Well, good luck.

[Edited on 24-3-2024 by bnull]

Texium - 24-3-2024 at 06:20

One caveat considering Zr’s resistance to HCl: papers that discuss metal corrosion resistance are generally considering a bulk piece of metal, whereas what you have will likely be a powder. Since powdered metals have a very high surface area, their properties can sometimes be very different than those of the bulk meta (e.g. you can melt and cast a chunk of bismuth no problem, but try melting some bismuth powder and it will oxidize faster than it melts).

I don’t have experience with Zr, but it’s possible that it will react with HCl as a powder in the presence of air. Won’t know until you try though!

Admagistr - 24-3-2024 at 07:25

It is true that in industry pure zirconium is not produced from ZrO2 by magnesium reduction and there are probably the reasons mentioned above. Apparently it would be very difficult and especially expensive to purify it if it were produced in this way... Very pure zirconium was, and perhaps still is, produced by steam decomposition of ZrI4 on hot thin tungsten filament.

bnull - 24-3-2024 at 09:24

Quote: Originally posted by Admagistr  
steam decomposition of ZrI4 on hot thin tungsten filament.

van Arkel process. Industry has switched to the Kroll process, while van Arkel is "still in use for the production of small quantities of ultra-pure titanium and zirconium" (Xu et al. Production of nuclear grade zirconium).

From the CRC Handbook 97th:
Quote:
Zirconium is produced commercially by reduction of the chloride [ZrCl4] with magnesium (the Kroll Process), and by other methods. It is a grayish-white lustrous metal. When finely divided, the metal may ignite spontaneously in air, especially at elevated temperatures. The solid metal is much more difficult to ignite.

And most probably Zr powder is sensitive to HCl, specially because of the oxygen dissolved in the acid solution.

Conure - 24-3-2024 at 12:34

Damn it, I knew it was too good to be true. I will still make a try. Thanks for all the info.

clearly_not_atara - 25-3-2024 at 06:37

Yes, the titanium group metals are especially difficult to reduce. That's why, for example, titanium is really expensive. Otherwise, it's much more common than copper or even zinc, so it should be cheaper, but those two are very easy to work with in comparison.

Metalysis claims that they can also produce zirconium by reduction of ZrO2 in molten CaCl2 with a sacrificial carbon anode (releasing CO instead of Cl2). Unfortunately they have not been able to make pure titanium by this process, but they may yet bring down the price of Zr.

Conure - 25-3-2024 at 12:59

Quote: Originally posted by bnull  

And most probably Zr powder is sensitive to HCl, specially because of the oxygen dissolved in the acid solution.

Do you think the same is true for ZrO2?

[Edited on 25-3-2024 by Conure]

[Edited on 25-3-2024 by Conure]

[Edited on 25-3-2024 by Conure]

[Edited on 25-3-2024 by Conure]

Admagistr - 25-3-2024 at 14:59

Quote: Originally posted by Conure  
Quote: Originally posted by bnull  

And most probably Zr powder is sensitive to HCl, specially because of the oxygen dissolved in the acid solution.

Do you think the same is true for ZrO2?

ZrO2, especially that formed under heat, is very chemically inert, hence insoluble in HCl even in the powdered state. Removing ZrO2 from the resulting mixture is the most difficult task. HF would certainly do the job, but it is extremely dangerous and dissolves Zr metal. It could also be done with KHSO4, but again the same problem is that the zirconium would not survive...