Sciencemadness Discussion Board

Pulverizing Ni/Al for Raney Nickel

Mr. Rogers - 30-11-2018 at 13:25

Could one use a rock tumbler to powderize this alloy to make Raney Nickel? What type of media would you use in the tumbler?

https://www.ebay.com/itm/Nickel-aluminum-alloy-300g-for-the-...

Loptr - 30-11-2018 at 13:29

You dont. You dissolve the aluminum away using a base bath.

Mr. Rogers - 30-11-2018 at 13:31

Quote: Originally posted by Loptr  
You dont. You dissolve the aluminum away using a base bath.


Right -- but these are large chunks of the alloy. You'd have to get it to a smaller size first before using the base.

Deathunter88 - 30-11-2018 at 13:38

Quote: Originally posted by Mr. Rogers  
Quote: Originally posted by Loptr  
You dont. You dissolve the aluminum away using a base bath.


Right -- but these are large chunks of the alloy. You'd have to get it to a smaller size first before using the base.


No you don't, once you dissolve the Al the chunks break apart.

Mr. Rogers - 30-11-2018 at 13:39

Quote: Originally posted by Deathunter88  
Quote: Originally posted by Mr. Rogers  
Quote: Originally posted by Loptr  
You dont. You dissolve the aluminum away using a base bath.


Right -- but these are large chunks of the alloy. You'd have to get it to a smaller size first before using the base.


No you don't, once you dissolve the Al the chunks break apart.


OK.. Super!.

AJKOER - 2-12-2018 at 05:40

Actually, you just have to remove/weaken the protective Al2O3 coating. I would try test heating the surface on a small piece till its red hot and place in a very dilute solution of NH3/NH4+, Club Soda plus a bit of NaCl. Give it time (or, jump start the mix in a microwave), at which point any exposed Al, an active metal, will be attacked by water liberating H2 gas. You may wish to compare results with a test process that does not first heat treat to assess the benefits, if any. Also, compare to the expensive and dangers of using NaOH.

Be careful where you do the dissolution as hydrogen/air mixture has a wide explosive range!

Also, some nickel may dissolve (in an electrochemical reaction paralleling the metal copper) from NH3 and air exposure, so reduce O2 exposure (which I one reason for the CO2 presence). Treat the created solution as toxic waste and add washing soda (Na2CO3).

[Edited on 2-12-2018 by AJKOER]

Tsjerk - 2-12-2018 at 06:03

@AJOEKER ; you are confusing aluminium foil with this alloy.

AJKOER - 2-12-2018 at 06:23

Quote: Originally posted by Tsjerk  
@AJOEKER ; you are confusing aluminium foil with this alloy.


Possibly, but as it is not Raney nickel (which is an alloy of Al and Ni, where most of the aluminum has been already removed with NaOH).

It is some Al/Ni alloy. Weighing a piece of the dry metal and noting the volume of water it displaces (a density check) may give a clue as to the Aluminum content.

Now, there exists many Al alloys rich in metal additives, so not clear if attempting to test treat it as if were one of the Al alloy foils is not appropriate, assuming there is way too much Al presence, before the usual NaOH treatment in the preparation of Raney nickel.

Start small scale and test, test,...
-------------------------------------------

Of possible relevance, I recently try to flame treat one of those thicker Al made pans for take-off food.

I was shocked on how much of the Al pan just disappeared in the flame, opposite of what I expected, worst than with heavy duty (likely heat annealed) Al foil.

So test of a flame treatment of larger pieces of Al/Ni may prove helpful, but do in a strong vent, holding your breath, as metal fumes (especially nickel) are dangerous!

[Edited on 2-12-2018 by AJKOER]

unionised - 2-12-2018 at 07:23

Quote: Originally posted by AJKOER  
Quote: Originally posted by Tsjerk  
@AJOEKER ; you are confusing aluminium foil with this alloy.

holding your breath, as metal fumes (especially nickel) are dangerous!

[Edited on 2-12-2018 by AJKOER]


and today's "dangerous nonsense" award gores to Ajkoer.

unionised - 2-12-2018 at 07:48

Quote: Originally posted by AJKOER  
Actually, you just have to remove/weaken the protective Al2O3 coating.


[Edited on 2-12-2018 by AJKOER]

The sodium hydroxide will do that.

AJKOER. do you realise that the sole purpose of this material is to make Raney Ni by dissolving away the Al with NaOH?
It works.

AJKOER - 2-12-2018 at 10:52

Quote: Originally posted by unionised  
Quote: Originally posted by AJKOER  
Actually, you just have to remove/weaken the protective Al2O3 coating.


[Edited on 2-12-2018 by AJKOER]

The sodium hydroxide will do that.

AJKOER. do you realise that the sole purpose of this material is to make Raney Ni by dissolving away the Al with NaOH?
It works.


Perhaps you can agree that, as I said:

"It is some Al/Ni alloy. Weighing a piece of the dry metal and noting the volume of water it displaces (a density check) may give a clue as to the Aluminum content."

This is important because of the target pre-leaching alloy composition is equal metal weights of Al and Ni. To quote a source (https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/r/Raney_...):

"The initial alloy composition is important because the quenching process produces a number of different Ni/Al phases that have different leaching properties. This may result in markedly different porosities in the end product. The most common starting alloy used in industry contains an equal amount per weight of nickel and aluminium, incidentally, the same ratio Murray Raney used in his discovery of Raney nickel."

Also:

"Raney nickel is produced when a block of nickel-aluminium alloy is treated with concentrated sodium hydroxide. This treatment, called "activation", dissolves most of the aluminium out of the alloy. The porous structure left behind has a large surface area, which gives high catalytic activity. A typical catalyst is around 85-percent nickel by mass, corresponding to about two atoms of nickel for every atom of aluminium. The aluminium which remains helps to preserve the pore structure of the overall catalyst."

So mindless leaching with NaOH of an existing Al/Ni alloy of unknown composition is not likely a path that creates a highly active Raney nickel like product, in my opinion.
---------------------------------------------------------------

So, the real question is how does one possibly correct the starting alloy composition to come close to a functional final Raney nickel like product?

Some radical heating/combustion path possibly to adjust the alloy composition, but still a long shot.
------------------------------------------------

Also, per the same source to quote:

"A high catalytic activity, coupled with the fact that hydrogen is absorbed within the pores of the catalyst during activation, makes Raney nickel a useful catalyst for many hydrogenation reactions."

Note, I have suggested on occasion on this forum, the use of Al with hydrogen atom radical chemisorbed on the Aluminum metal surface. It should be noted that the active radical .H does not remain long on the surface, and with time, forms hydrogen:

.H + .H = H2 (g)

So don't use the NaOH activation step for Raney nickel too long before its use.

[Edited on 2-12-2018 by AJKOER]

Loptr - 2-12-2018 at 11:07

This is the claimed composition

Size 10-25mm
Composition: nickel 46.7%
aluminum 50.9%
titanium 2.3%

Mr. Rogers - 2-12-2018 at 11:14

This is being sold with a specific composition for the purpose of making a catalyst equivalent to Raney nickel.

There is always a chance the alloy isn't what the seller claims, but that can be true of almost anything one intends to purchase.

S.C. Wack - 2-12-2018 at 13:28

Ukraine? Titanium? Who sells Raney alloy with Ti in it? Is there actually organic chemistry lit using Ti-promoted Ni? (fuel cell activity is for fuel cells) I'm not aware of any, and am under the impression that proper alloy crushes relatively easily. Pretty sure one can google some research on the use of ball mills to produce active Ni...but not in the way you think. I'm surprised no jackass has yet got the listing deleted for not shipping hazmat.

unionised - 2-12-2018 at 13:41

Quote: Originally posted by AJKOER  
Quote: Originally posted by unionised  
Quote: Originally posted by AJKOER  
Actually, you just have to remove/weaken the protective Al2O3 coating.


[Edited on 2-12-2018 by AJKOER]

The sodium hydroxide will do that.

AJKOER. do you realise that the sole purpose of this material is to make Raney Ni by dissolving away the Al with NaOH?
It works.


Perhaps you can agree that, as I said:

"It is some Al/Ni alloy. Weighing a piece of the dry metal and noting the volume of water it displaces (a density check) may give a clue as to the Aluminum content."

This is important because of the target pre-leaching alloy composition is equal metal weights of Al and Ni. To quote a source (https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/r/Raney_...):

"The initial alloy composition is important because the quenching process produces a number of different Ni/Al phases that have different leaching properties. This may result in markedly different porosities in the end product. The most common starting alloy used in industry contains an equal amount per weight of nickel and aluminium, incidentally, the same ratio Murray Raney used in his discovery of Raney nickel."

Also:

"Raney nickel is produced when a block of nickel-aluminium alloy is treated with concentrated sodium hydroxide. This treatment, called "activation", dissolves most of the aluminium out of the alloy. The porous structure left behind has a large surface area, which gives high catalytic activity. A typical catalyst is around 85-percent nickel by mass, corresponding to about two atoms of nickel for every atom of aluminium. The aluminium which remains helps to preserve the pore structure of the overall catalyst."

So mindless leaching with NaOH of an existing Al/Ni alloy of unknown composition is not likely a path that creates a highly active Raney nickel like product, in my opinion.
---------------------------------------------------------------

So, the real question is how does one possibly correct the starting alloy composition to come close to a functional final Raney nickel like product?

Some radical heating/combustion path possibly to adjust the alloy composition, but still a long shot.
------------------------------------------------

Also, per the same source to quote:

"A high catalytic activity, coupled with the fact that hydrogen is absorbed within the pores of the catalyst during activation, makes Raney nickel a useful catalyst for many hydrogenation reactions."

Note, I have suggested on occasion on this forum, the use of Al with hydrogen atom radical chemisorbed on the Aluminum metal surface. It should be noted that the active radical .H does not remain long on the surface, and with time, forms hydrogen:

.H + .H = H2 (g)

So don't use the NaOH activation step for Raney nickel too long before its use.

[Edited on 2-12-2018 by AJKOER]



"So mindless leaching with NaOH of an existing Al/Ni alloy of unknown composition is not likely a path that creates a highly active Raney nickel like product, in my opinion."
How fortunate, then, that nobody is suggesting such a thing.

"Raney nickel is produced when a block of nickel-aluminium alloy is treated with concentrated sodium hydroxide. "

The important word there is "block"

S.C. Wack - 2-12-2018 at 13:49

I've read dozens of articles that dissolve the Al but don't remember any that specified not-powder, except perhaps some newer articles where leaching was interrupted for the purpose of investigating WTF is going on.

Mr. Rogers - 2-12-2018 at 15:11

Quote: Originally posted by S.C. Wack  
Ukraine? Titanium? Who sells Raney alloy with Ti in it? Is there actually organic chemistry lit using Ti-promoted Ni? (fuel cell activity is for fuel cells) I'm not aware of any, and am under the impression that proper alloy crushes relatively easily. Pretty sure one can google some research on the use of ball mills to produce active Ni...but not in the way you think. I'm surprised no jackass has yet got the listing deleted for not shipping hazmat.


This is what WP has to say about the Ti:
Quote:
The Ni–Al alloy is prepared by dissolving nickel in molten aluminium followed by cooling ("quenching"). Depending on the Ni:Al ratio, quenching produces a number of different phases. During the quenching procedure, small amounts of a third metal, such as zinc or chromium, are added to enhance the activity of the resulting catalyst. This third metal is called a "promoter".[7] The promoter changes the mixture from a binary alloy to a ternary alloy, which can lead to different quenching and leaching properties during activation.

Mr. Rogers - 2-12-2018 at 15:17

Quote: Originally posted by S.C. Wack  
I'm surprised no jackass has yet got the listing deleted for not shipping hazmat.


Please don't. If everyone here complained about their particular chemical pet-peeve to Ebay, we'd have nothing left to buy.

S.C. Wack - 2-12-2018 at 15:29

That is my pet peeve of ebay, people reporting things as requiring hazmat when it isn't hazmat. Your quote says nothing of Ti and no one sells such alloy, so I question why anyone would make it for sale, or why they wouldn't powder it.

JJay - 2-12-2018 at 17:50

OrgSyn specifies a powdered nickel-aluminum alloy for making a W-6 Raney nickel catalyst: http://www.orgsyn.org/demo.aspx?prep=CV3P0176

[Edited on 3-12-2018 by JJay]

Loptr - 2-12-2018 at 20:04

Yeah, I have fought eBay on Sodium metal and NaBH4, but as it turns out their policy is very straightforward. If the USPS has it listed under Pub52 as not allowed, then they dont allow it to be sold.

I still still them onto the site evey now and again. I do ship properly by the way...