trip96
Harmless
Posts: 16
Registered: 23-7-2012
Member Is Offline
Mood: No Mood
|
|
What reagents can I make from ash?
Hey everyone! I heat my house in winter via a wood burning stove. As you can imagine I end up with garbage pales worth of ash at the end of it.
What usefull reagents could I make using ash?
Let's build a list!
|
|
marko
Harmless
Posts: 21
Registered: 18-2-2012
Member Is Offline
Mood: No Mood
|
|
Mostly NaOH, KOH. I suppose much of it would turn to carbonate. I think it depends on the type of wood - most is higher in K. (hence "potash"...
pot... ash... from which we get 'potassium').
In the old days you'd leech the lye from the ash with water, and use it to make soap.
I'd imagine there is some other mineral content, but much lower quantity.
|
|
elementcollector1
International Hazard
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
I still don't understand how KOH results from the burning of wood. I always assumed they meant you had to treat the K2CO3 with Ca(OH)2, and that would
form your KOH.
EDIT: Incidentally, is common gravel made of calcium hydroxide? Every lye page I go to says to filter the boiled carbonate or whatever through gravel
to obtain lye.
[Edited on 5-9-2012 by elementcollector1]
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
Poppy
Hazard to Others
Posts: 294
Registered: 3-11-2011
Member Is Offline
Mood: † chemical zombie
|
|
You can find everything from gold to uranium. Its just in minimal proportions. It's true. Just figure out how the elements have been throughly
dispersed in soil. Mercury is by most a rare element in ash, some of its compounds have a minuscle solubility product. Plants probabily would not take
any chance to suck a few atoms of this.
[Edited on 9-5-2012 by Poppy]
|
|
bbartlog
International Hazard
Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline
Mood: No Mood
|
|
Most of the ash is actually CaCO3 (but there is also MgCO3 and some silica compounds). But the stuff you can dissolve out is mostly K2CO3. There is
some KOH (the hotter the fire, the more KOH), but it tends to turn into K2CO3 if you leach it out with water and boil the resulting solution down, as
atmospheric CO2 is absorbed.
K2SO4 and small amounts of KCl can also be obtained if you perform fractional crystallization on the ley.
The less you bet, the more you lose when you win.
|
|
SM2
Hazard to Others
Posts: 359
Registered: 8-5-2012
Location: the Irish Springs
Member Is Offline
Mood: Affect
|
|
POTASH, "Pot-Ash" - Potassium. Yep, the water soluble portion is mostly potassium carbonate, and if your lucky, you can even filter through activated
charcoal.
An interesting thing to do, is wrap a small amount of solid Lye into a sheet of Al foil. Wind it up to make a nice turd. Then place it in a nice oak
fire. The Na formed will make quite a little show.
|
|
Poppy
Hazard to Others
Posts: 294
Registered: 3-11-2011
Member Is Offline
Mood: † chemical zombie
|
|
What sodium o0?
Elemental sodium??????
|
|
Vargouille
Hazard to Others
Posts: 380
Registered: 16-4-2012
Member Is Offline
Mood: No Mood
|
|
At elevated temperatures there should be a small amount of the sodium formed, which reacts with moisture in the air immediately due to the heat,
reforming sodium hydroxide, and the cycle continues until the aluminum is used up. It may even be to such a small degree that the flame is almost
indistinguishable from a sodium salt burning at high temperatures. I'm searching for a formula, or several, to test this, but it may take some time.
EDIT: As predicted, but not quantified, by the Nerst Equation, adapted from its typical use as a wet electrochemical equation. Here, Eo is -1.05V, T is a large, unknown quantity, z
is 3 e-, and (ln Q) is a negative value, meaning that the amount of product is less than the amount of reactants at a particular point.
With a very small amount of sodium formed and a very high temperature, E>0, such that the reaction proceeds. Unless, of course, I am ignoring some
other part of the physics behind the chemistry.
[Edited on 6-9-2012 by Vargouille]
|
|
Poppy
Hazard to Others
Posts: 294
Registered: 3-11-2011
Member Is Offline
Mood: † chemical zombie
|
|
Not sure Na is a strong base Al is amphoteric, probably some alumixodide would form
|
|
vmelkon
National Hazard
Posts: 669
Registered: 25-11-2011
Location: Canada
Member Is Offline
Mood: autoerotic asphyxiation
|
|
I don't think you can make sodium with NaOH+ Al. I have heated Draino with a torch. It fizzes and forms a rock hard solid that looks like salt. It
produces sodium aluminate.
|
|
elementcollector1
International Hazard
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
So, how does one recover pure KOH from this ashy mess? If I boil it down, it'll just absorb CO2 again. I can't evaporate it because KOH is too
hydroscopic.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
platedish29
Hazard to Self
Posts: 76
Registered: 2-9-2012
Member Is Offline
Mood: absorbing CO2
|
|
Once I collected ashes from a large pile, mixed with water, filtered and neutralised with nitric acid. I was not aware calcium compounds had been
filtered.
Then boiled and finally dried over an aluminium plate. I could even make black powder out of it!
Take this. Enjoy!
[Edited on 11-9-2012 by platedish29]
Attachment: misra93a.pdf (276kB) This file has been downloaded 528 times
|
|