Sciencemadness Discussion Board

Synthesis of calcium metal from compounds by use of potassium

John paul III - 28-4-2018 at 11:50

I came across an easy way to get K metal from K2O. I'd like to use it to get calcium metal from CaO, Ca(OH)2 or CaCO3. Can it be done (practically)?

[Edited on 28-4-2018 by John paul III]

aga - 28-4-2018 at 14:18

Starve.

Edit:

A new tactic. If it's complete rubbish, just say 'starve'.

Hopefully people will not reply to utter garbage thereafter.

[Edited on 28-4-2018 by aga]

Metacelsus - 28-4-2018 at 14:40

Can it be done? In theory Ca can be made by reacting K with CaO, since the reduction potential of K+ is more negative than that of Ca2+. However, I don't think it's very practical to actually do the reaction.

Industrially, Ca is produced from CaO by reaction with Al at >1200 °C, see: http://jes.ecsdl.org/content/89/1/207

[Edited on 4-28-2018 by Metacelsus]

Texium - 28-4-2018 at 14:56

Quote: Originally posted by aga  
Starve.

Edit:

A new tactic. If it's complete rubbish, just say 'starve'.

Hopefully people will not reply to utter garbage thereafter
How about not, unless you want a temporary ban for a couple weeks? Post "starve" one more time and that's exactly what you'll get. This isn't funny.

j_sum1 - 28-4-2018 at 15:01

Well, at a quick glance the thermodynamics is not unfavourable.
K2O heat of formation = -363 kJ/mol
CaO heat of formation = - 635 kJ/mol

The next step would be to do some research on designs of similar reactions. I suspect you will have very significant problems with your potassium boiling away. Now it might be kind of interesting to see a hot green metallic gas eminating from your apperatus. But only enjoyable from a considerable distance.



@ aga. Not a good tactic. Don't do this again. You have far more intelligence, knowledge and humour than this and don't need to be so dismissive. If the question bores you or you have nothing to contribute then don't respond. If everyone agrees with you the thread will sink like a stone.

Edit: ninja'd by Texium.

[Edited on 28-4-2018 by j_sum1]

LearnedAmateur - 28-4-2018 at 16:26

I’d also be keeping that potassium and figuring out other routes to obtain calcium metal, but I’ve already got a few grams of the latter for whenever I may need it during the course of experimentation. Personally, I’d go with electrolysis of a molten calcium salt under inert atmosphere if I were ever to attempt to isolate the element. But, if you’ve got loads of potassium to spare then who am I to dissuade you; it’s more reactive than calcium so you can utilise it as an extraction reagent through some processes.

John paul III - 29-4-2018 at 07:37

Quote: Originally posted by aga  
Starve.

Edit:

A new tactic. If it's complete rubbish, just say 'starve'.

Hopefully people will not reply to utter garbage thereafter.

[Edited on 28-4-2018 by aga]

I remind you that calcium can be used to fix nitrogen (calcium nitride), provided that you have an oxygen separator. Ideally I'd add drops of water to it collecting ammonia, and then recycle the calcium

John paul III - 29-4-2018 at 08:08

Quote: Originally posted by Metacelsus  
Can it be done? In theory Ca can be made by reacting K with CaO, since the reduction potential of K+ is more negative than that of Ca2+. However, I don't think it's very practical to actually do the reaction.

Industrially, Ca is produced from CaO by reaction with Al at >1200 °C, see: http://jes.ecsdl.org/content/89/1/207

[Edited on 4-28-2018 by Metacelsus]


Since potassium has a low melting point it should be easier to ignite the mix with CaO, right? (I realise that 1200C for the Al fueled thermite is way above melting point of aluminium) Potassium is sometimes used to ignite aluminium thermite

Beware, this paragraph will contain exotic ideas:

Now, the problem would be potassium boiling. I thought of reacting tiny quantities, in a kind of a "borehole" to contain the explosion products without producing shrapnel. Do you think the reaction could be fast enough?