making K2CO3 - Archive File

[megalomania]

the_wingman
Frequent Poster
Posts: 48
From:
Registered: JAN 2001
posted February 14, 2001 11:28 AM
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I read in a former topic that it's possible to make potassium carbonate from KNO3 and C.
Should 1 part KNO3 to 2 parts C work?
I tried it but I wasn't successful.


blackadder
Frequent Poster
Posts: 313
From: London
Registered: DEC 2000
posted February 14, 2001 01:43 PM
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Just wondering why you want potassium carbonate, when you can have kno3?
hehe

[This message has been edited by blackadder (edited February 14, 2001).]



firebreether
Frequent Poster
Posts: 109
From:
Registered: NOV 2000
posted February 14, 2001 02:43 PM
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Probably wants to make fulminating powder.
right?



jin
Frequent Poster
Posts: 111
From: uk
Registered: SEP 2000
posted February 14, 2001 02:49 PM
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its been a few years since i have done it,but i think its the same as normal gunpowder without the sulphur 2kno3+3c=k2co3+3co
try 3 parts kno3 and 1c if that will not work try 2 parts c.
[This message has been edited by jin (edited February 14, 2001).]



Mammut
A new voice
Posts: 39
From: Essen,NRW,Germany
Registered: JAN 2001
posted February 28, 2001 09:52 AM
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quote:
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Originally posted by the_wingman:
I read in a former topic that it's possible to make potassium carbonate from KNO3 and C.
Should 1 part KNO3 to 2 parts C work?
I tried it but I wasn't successful.
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U have KNO3 and u will make K2CO3 oh oh oh
I can tell u a easier way to make K2CO3, if u give me the KNO3




J
Moderator
Posts: 605
From: United Kingdom
Registered: SEP 2000
posted February 28, 2001 11:14 AM
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Why not tell us all?
J

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"If the aquarium water has to be drunk don't waste the fish. In fact they'll probably be the easiest to eat even if you don't need the water. The cat is next in the pot." - John 'Lofty' Wiseman



SMAG 12B/E5
Frequent Poster
Posts: 61
From:
Registered: FEB 2001
posted March 16, 2001 11:16 PM
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You can obtain potassium carbonate from some pool suppliers for akaline Ph adjustment of water or leach it from wood ashes.
[This message has been edited by SMAG 12B/E5 (edited March 16, 2001).]



Agent Blak
Frequent Poster
Posts: 770
From: Sk. Canada
Registered: SEP 2000
posted March 18, 2001 01:40 PM
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Can't you also get K2CO3 as Baking Powder? I will check the Pool thing today.

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A wise man once said:
"...I Am Not Much of a Dancer But,
Just Wait Till The Fucking Begins"

Agent Blak-------OUT!!



Anthony
Moderator
Posts: 2321
From: England
Registered: SEP 2000
posted March 18, 2001 02:04 PM
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Baking soda is sodium bicarbonate
washing crystals are sodium carbonate

[megalomania]

In my estimation the best source of potassium carbonate is from wood ash. As a frequent fireplace user I have access to large volumes of the stuff. It is quite readily soluable from the ash, from which it can be filtered. I can't vouch for the purity, but after a few recrystillizations one can get fairly ash free crystals. There may be some other soluable components, but the vast majority is potassium carbonate. I recommend using cheap shop towls for the initial filtration to remove the bulk of the ash after steeping the ash in hot water. This filtered water can then be subjected to more vigerous filtration methods.

[jeffchem2000]

if you are going to collect the potash from ashes make sure that the wood wasn't treated because they leave some nasties in the ash. I don't know what exactly but they could be copper and arsenic salts. They also make the solution a yellowy green colour.

[frogfot]

Some year ago I burned a mix of 100 g KNO3 and 50 g coarse C to ubtain K2CO3 also. I wrote down yield of extracted solid to 49 g (91%).

[matjaz]

megalomania:
In my estimation the best source of potassium carbonate is from wood ash. ...
... This filtered water can then be subjected to more vigerous filtration methods.Any recall of the yield you've got?

I just washed some 100g of ash (mixture with lots of charcoal pieces :rolleyes: ) last night. Used a nylon sock to filter off the charcoal and got some 1/2 l of darkgrey slurry. This morning, I noticed that the slurry settled to the bottom 1/3 of the cup and I could decant crystal clear colourless solution from the top. I figure, I'd get at least 66% of all K2CO3 this way since it's so soluble. Will post the results when I get the crystals and weigh them.

[matjaz]

(couldn't EDIT, 1440 min limit... please join this msg with the previous one if you see fit)

The dirty bottom third settled again to 1/2 mud, 1/2 clear solution so i could decant another 70ml. This makes 300ml of the solution, pH=10-11. 15ml of this were dried in a petri dish on the room heating radiator. I got 200mg of dry crystals of potash, probably not a very pure one,
tiny fragile dirty-white crystals. My 300ml solution should thus contain 4g of K2CO3. Since my ash had a LOT of charcoal pieces mixed in, I'd say 4g of potash from 40g-60g of pure ashes.

This makes around 10% by weight of K2CO3 in wood ash (beech-wood I believe). The only pain is to get rid of all the water. If less water is used, the fraction you can pour off is smaller, reducing yield.