Sciencemadness Discussion Board

Calcium metal by chemical means

hkparker - 15-12-2010 at 16:22

Anyone have experience isolating calcium metal not electrochemically, perhaps a displacement from its salts?

Fleaker - 15-12-2010 at 18:37

Sadly, no.

If anyone has any ideas, post them up!

I don't think anyone here has ever synthed calcium electrochemically either.

hkparker - 15-12-2010 at 18:42

Isnt it produced by electrolysis on the industrial scale?

gsd - 15-12-2010 at 19:03

www.google.com

Gsd

hkparker - 15-12-2010 at 19:14

Yes thank you for the link :P. Its produced by the electrolysis of molten CaCl2, which is what I expected, but I would imagine it could be reduced by something, and I'm really hoping for a chemical method. Ill try a reaction between Ca(OH)2 and Mg, see if it is analagous to the reaction between sodium hydroxide and magnesium.

starch - 15-12-2010 at 22:15

Posted this else where thought it might help make a start

Calcium in the home - russian to english

Hex

P2Pochetny Retired
Apr 18 2005, 17:23
[Post = 491774]

Rated as: Excellent
So, Lord, I have perfected the technique for obtaining calcium in the home.
Unfortunately the resulting calcium is not so clean, so use it for chemical purposes, but quite suitable for drying chemical solvents, which I think is quite important. Especially for those people who are not able to get the sodium.

The equation of the reaction:

6CaO 2Al ---> 3CaO * Al2O3 3Ca

Methodology:

From the calculated amount of lime and powder (not powder) is made of aluminum mixture. Avoid contact with the mixture of air and moisture. Aluminum take 10% more than calculated by the equation of the reaction. From the resulting mixture is pressed into briquettes. Better that the mass of pellets was not less than 100 g. I do not know will the jack, because I am using for this purpose hydraulic press (you can arrange to have done so familiar on some production).
Briquette placed in a large pot of hromonikelievoy steel. Ignite briquettes using a standard mixture of aluminum powder and barium peroxide, but can also magnesium ribbon. Once the briquettes will light up, close the pot lid and wait for the end of the reaction. The best thing to do all this in the open air, putting the pot on peskok away from flammable materials.
When burned wait to cold. I for one am waiting until cooled completely. then knock out the reaction products in a bowl of kerosene and crushed with pestle. Calcium is formed in the form of drop-shaped inclusions of the entire mass of the formed reaction products. These beads I choose with tweezers and putting it into a jar for storage. The remaining waste is no need to throw out in trash. Before, I just carefully poured the case with water, but in recent years simply buried in the ground.

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FerroMan

Someone
Apr 18 2005, 18:20
[Post = 491777]


And outputs are: rolleyes:

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MoonLight

Junior Chemist
Apr 18 2005, 20:13
[Post = 491782]


Ah

I quietly mleyu. Well you must, who would have thought - calcium in the kitchen without electrolysis!

Cool!

Hex, and how important it is compressed into dense briquettes? What happens if you do not compress?

And where is taken aluminum powder? And how small?



I thought of another application of calcium: AFAIK, its reduction potential is higher than that of sodium. That is, if you throw pieces of calcium in a bowl of molten NaOH (as it melts, as is known, easy and low), then theoretically get sodium. Only after some time, with some mixing and how free of calcium - unknown .... hum .... But still it was amusing to get sodium without electrolysis:)



MoonLight

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Hex

P2Pochetny Retired
Apr 18 2005, 21:46
[Post = 491798]


If not pressed, then the mixture will not burn evenly, and would spit and splash. Output will suffer. But calcium is still raised.

Aluminum powder, so what is usually taken for termites. How hours after suffering a file or sandpaper to sharpen.

The theory about the sodium, I see. But I think this is unlikely.

For FerromEna:

Output is not considered. But my good. Just active metals weigh quite problematic. Just in this case, at such low cost of raw materials is relevant only for theoretical calculations, since quicklime lot on any construction site, and aluminum - in the worst case, you can let the sawdust on the old pot. The entire chip is in the crucible. Portselyanovy not work, because crack nafig!

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zaratystra

Old Junior Chemist
Apr 19 2005, 08:51
[Post = 491823]


By the way calcium is very well produced about electrolysis CaCl2.

Salt relatively low-melting and therefore the melt is lowered iron electrode and the electrolysis carried out by dc!

Calcium is released in the form of needles ...

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Clavik

The Catcher In The Rye
Apr 19 2005, 22:07
[Post = 491861]


But the interest is: is it possible in such a way to get magnesium, replacing CaO by MgO?

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Flyer

Someone
Apr 19 2005, 22:54
[Post = 491865]


quote
By the way calcium is very well produced about electrolysis CaCl2.

The question of obtaining calcium hurts one of my friend.
There are some problems that he described to me:
1) with elekrolizerom need to play around (pony that once and for ever)
2) Calcium chloride is soluble in excellent Kaltz - the problem of allocation of the product.

However, it ineteresuet question - Is the electrolysis of CaCl2 solutions of non-aqueous solvents?


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militsyya

Lord of the Flies
Dec 17 2005, 00:28
[Post = 497823]


quote
Ignite briquettes using a standard mixture of aluminum powder and barium peroxide, but you can also magnesium ribbon

And why should burn down this way? should be initially high temperature?

may be time to briquette drip of benzene and bring a torch? : D

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Hex

P2Pochetny Retired
Dec 17 2005, 00:47
[Post = 497826]


quote
And why should burn down this way? should be initially high temperature?

may be time to briquette drip of benzene and bring a torch?


In fact, this reaction metallothermy.
The ignition temperature even calcium-aluminum very high.
I do not understand the part about benzene? Kerosene are added in order to improve the shrinkage and compressibility of the mixture.
Splinter not tried: D Hunter's matches should be fine.

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militsyya

Lord of the Flies
Dec 17 2005, 01:18
[Post = 497827]


quote
I do not understand the part about benzene?

I suggested once to get the heat: rolleyes: in benzene rather large heat of combustion, I thought it might contribute to the initiation of the reaction: gigi:

and barium peroxide obtained from BaCl2 and H2O2, as I understand it?

quote
. Ignite briquettes using the standard mixture of aluminum powder and barium peroxide
and how much should such a mixture in relation to the contents of the crucible? and where to put this "fuse"? Sorry for the possibly stupid questions, I'm not special: gigi:

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zaratystra

Old Junior Chemist
Dec 17 2005, 01:34
[Post = 497828]


and barium peroxide obtained from BaCl2 and H2O2, as I understand it?

Izdevaeshsya? :)

No, of course. BaO calcination at 500-600 C.

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zaratystra

Old Junior Chemist
Dec 17 2005, 1:36
[Post = 497829]


In fact, this reaction metallothermy.

Specifically aluminothermy!

I read this инфу that metallic rubidium obtained from its hydroxide vostanavlivaya aluminum in a vacuum!

I think so, and potassium can.

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zaratystra

Old Junior Chemist
Dec 17 2005, 01:39
[Post = 497830]


Calcium chloride is soluble in excellent Kaltz - the problem of allocation of the product.

I do remember reading in the book - from the melt pretty well.
The only problnma there he grows in the form of needles and it is likely short-circuit between the anode and cathode!


However, it ineteresuet question - Is the electrolysis of CaCl2 solutions of non-aqueous solvents?

I think probably only a matter of selection of solvent!

For lithium pyridine and for calcium??

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Hex

P2Pochetny Retired
Dec 17 2005, 21:51
[Post = 497859]


And that, for calcium pyridine, did not fit?

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steel

Old Junior Chemist
Jan 12 2010, 8:40
[Post = 532665]


And if not get calcium and aluminum alloy containing a few percent of calcium? Such an alloy can be crushed and theoretically be used instead of zinc or magnesium in the reductive amination of amines with acetate in alcohol, I think he will react. It is interesting to not detonate a mixture of aluminum oxide and calcium if it does not ignite as zapresovat in a metal pipe to smear both sides with clay and put in a boiler at about 1000 degrees.

I would like to make mix 80 grams of aluminum powder and 20 g of calcium oxide into the tube zapresovat plastered with clay and cast in a coal boiler or process gas burner hot and then cool down and knock out stable in the air alloy of aluminum and a few percent of calcium. It is also interesting to take the place of calcium oxide, chloride, anhydrous aluminum chloride on the idea of dolzhet evaporate leaving a net calcium

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chemister

Boss Liberia
Jan 27 2010, 16:53
[Post = 532984]


Thermodynamics against the restoration of calcium oxide, aluminum:
3CaO + 2Al -> Al2O3 + 3 Ca dG = -1582 - 3 * (-604) = + 230 kJ

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namgramk

The world of dream
Jan 27 2010, 17:26
[Post = 532985]


quote (said: chemister)
dG = -1582 - 3 * (-604) = + 230 kJ

In other words, the reaction should not go. But Gexa was an excess of CaO, the equation was obtained calcium aluminate. Maybe, in this case?

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Black Angel

Someone
Jan 31 2010, 5:05
[Post = 533106]

Rated as: Interesting!
Aluminothermy,: gigi:

That calcium aluminates - and most likely a mixture of dicalcium and tricalcium aluminate. Therefore, the stoichiometry considered here is difficult, given the fact that part of the aluminum stupidly burnt out in air.
As the crucible can be used pit lined with bricks on top, too ... Must need a good high-temperature insulation - in a metal crucible (read cutting pipe) due to the high thermal conductivity of metal, the reaction near the wall does not go. Shortcrust sand crucible little help, in an extreme case the hill of sand stuck in a crucible with the same conventional thermite mixture - for heating, and then actually sabzh.
The best heat insulator obtained from granular calcium nitrate (fertilizer shop, if you can find) in a mixture of: 1 volume of pellet, 0.5 volume of flour, 0.5 volume of sugar - in the ignition of Bengal fire is burning quite calm with the formation as a combustion finely porous enough a solid mass consisting of almost pure SaO. The temperature of the combustion of such mixtures - at 2000 degrees - measured by pyrometer.
1000 degrees for the start of the reaction SaO and Al are not enough, yet turned out powdering termite and Bengal lights.
Aluminum powder, as well as other soft metal's great for grinding machine (the cheapest)) modernized, pridelyvaniem thereto frequency converter to 220V and the power of the engine or higher - or at high speed powder burns bright flame. It is not OTC, but not expensive by present prices.
A mixture of aluminum with a lime squeeze necessarily different outputs fall by orders of magnitude. And finally - a small amount of mixture is better not to try - 30 or 1950 just nesrabotayut, due to lower temperatures at the cold walls of the crucible.

Written in memory of Father, who aluminates of calcium dog ate it, though he did limestone, steel slag and aluminum powder, and the goal was just aluminate, and calcium was obtained in very small quantities.

hkparker - 15-12-2010 at 22:20

Wow long post, but I looked over the chemistry. So it sounds like an aluminothermic reaction is possible, but the yields are iffy. Worth a try though, thanks!

starch - 15-12-2010 at 22:24

no problem at all

ya sorry bout long post i didnt want to try and condense it down incase i wreaked it :)

she needs some heat too :o

blogfast25 - 16-12-2010 at 09:18

Sigh… another wild goose chase by those unwilling to consider condition 1: Is It Possible, Thermodynamically?

CaO HoF = - 635 kJ/mol
Al2O3 = - 1676 kJ/mol

CaO + 2/3 Al --- > Ca + 1/3 Al2O3, Heat of Reaction = + 635 – 1/3 1676 = + 76 kJ/mol, reaction is (strongly) endothermic and unless you have a trick up your sleeve to force the equilibrium from left to right nothing will happen.

Calcium is in fact occasionally used where aluminium fails as an oxide reducing agent, the technique is then called calciothermy. V2O5 has been reduced with Ca for instance and early production of metallic U (from UO2) also used Ca (now Mg with UF4). Drawback of Ca is that CaO has an insanely high MP, not desirable in most oxide reductions.

One potential trick is to heat a mitxure of CaO and Al to very high temperature under vacuum: Ca has a lower BP (1,484C) than Al (2,519C) and the Ca could thus in (unsubstantiated) theory be selectively boiled off. Good luck with that!

Ca is produced electrochemically because it’s the only PRACTICAL way.

One could of course envisage various reducing agents in very extreme conditions and never be able to bench test it because the conditions required. CaO + C --- > Ca + CO is a possibility because at very high temperature (x,000 C) the volatile Ca and CO drive the equilibrium to the right, IF you can successfully remove them form the mix. That would involve probably high vacuum on top of the high temperatures. Again, bonne chance!

The communications published above are likely by bullshitting freewheelers…



[Edited on 16-12-2010 by blogfast25]

hkparker - 16-12-2010 at 09:22

Ok, I'm sure electrolysis is the practical on the industrial scale, just wondering if anyones seen a powerful enough reducing agent user sucessfully. I'm absolutly considering if its possible and thermodynamically favorable.

blogfast25 - 16-12-2010 at 09:31

Quote: Originally posted by hkparker  
Ok, I'm sure electrolysis is the practical on the industrial scale, just wondering if anyones seen a powerful enough reducing agent user sucessfully. I'm absolutly considering if its possible and thermodynamically favorable.


I'll gladly and very publicly eat my hat if someone here can pull off chemical calcium in a home lab setting... :D

hkparker - 16-12-2010 at 09:53

haha :P ok

Eclectic - 16-12-2010 at 09:57

Does metallic calcium from calcium hydride count? :P

(Surplus military hydrogen generators from radio rescue sets)

[Edited on 12-16-2010 by Eclectic]

blogfast25 - 16-12-2010 at 10:43

Quote: Originally posted by Eclectic  
Does metallic calcium from calcium hydride count? :P

(Surplus military hydrogen generators from radio rescue sets)

[Edited on 12-16-2010 by Eclectic]


You don't think that making CaH2 from calcium and hydrogen to make... erm, calcium, is a little, shall we say, redundant? :D

Calcium metal shouldn't be particularly hard to buy. Buy calcium, stimulate the economy!

[Edited on 16-12-2010 by blogfast25]

hkparker - 16-12-2010 at 10:58

Haha ok

Eclectic - 16-12-2010 at 11:09

The hydrogen generators from Fair Radio Sales each contain about 2kg of CaH.

blogfast25 - 16-12-2010 at 11:31

Quote: Originally posted by Eclectic  
The hydrogen generators from Fair Radio Sales each contain about 2kg of CaH.


So what's the purpose of the CaH in that application? And is it unadulterated or compounded?

[Edited on 16-12-2010 by blogfast25]

Eclectic - 16-12-2010 at 12:08

It's lump CaH, kinda looks like grey chalk, made by Metal Hydrides, inc from late WWII through Viet Nam. 1960's

Can is opened with key and pulled out to make sea water immersion activated hydrogen generator for inflating balloon to raise radio antenna wire.

Earlier versions used LiH. Google M-315 hydrogen generator.

hkparker - 16-12-2010 at 12:11

Sounds cool. I think id rather buy calcium though lol, but that's neat

blogfast25 - 16-12-2010 at 12:47

Quote: Originally posted by Eclectic  
It's lump CaH, kinda looks like grey chalk, made by Metal Hydrides, inc from late WWII through Viet Nam. 1960's

Can is opened with key and pulled out to make sea water immersion activated hydrogen generator for inflating balloon to raise radio antenna wire.

Earlier versions used LiH. Google M-315 hydrogen generator.


Interesting. Will search. Seems like a complicated way of rasing an antenna though... :)