RogueRose
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Very high temp (3000+ deg F) reaction vessel - uses in chem?
After getting my forge working the way I want, I am finally ready to make my final version of the unit which will allow for even higher temps,
multiple fuels and larger interior space. I have successfully melted cast iron with wood as fuel (which I was told wasn't possible - charcoal or coal
would be needed) so I feel confident that the new design should be capable of much higher temps as it will/can operate with coal/charcoal and at a
higher air pressure from a new blower. The only issue will be finding reaction vessels to handle the high temps (carbide crucibles).
I'm wondering if there are many uses for an oven/forge in chemistry for doing whatever possible in a home lab setup. I'm basically looking for
reactions that need high heat to either break down, oxidize or whatever.
Are there any interesting experiments/reactions that can be done with high temp furnaces like this?
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JJay
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There are definitely lots of interesting high temperature reactions: Carbon reductions, phosphorus reactions, thermal decomposition reactions....
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careysub
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You can prepare/regenerate some excellent desiccating agents - calcium oxide (600 °C), magnesium oxide (800 °C), and barium oxide (800-1000 °C).
You can prepare potassium cyanide by the Wagner process (650 °C):
K4[Fe(CN)6] + K2CO3 + C => 6KCN + Fe + CO2 + CO
You melt a whole bunch of elements (up to iron, maybe even titanium) and thus can prepare mixtures of same (alloys, etc.) or cast them into useful
shapes.
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RogueRose
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Quote: Originally posted by careysub  | You can prepare/regenerate some excellent desiccating agents - calcium oxide (600 °C), magnesium oxide (800 °C), and barium oxide (800-1000 °C).
You can prepare potassium cyanide by the Wagner process (650 °C):
K4[Fe(CN)6] + K2CO3 + C => 6KCN + Fe + CO2 + CO
You melt a whole bunch of elements (up to iron, maybe even titanium) and thus can prepare mixtures of same (alloys, etc.) or cast them into
useful shapes. |
This was the purpose of the device in the first place and found it has a number of other interesting uses as well!
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aga
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The major problem with charcoal or coke fuelled furnaces is the ton of carbon bits floating about due to the forced air.
Carbon bits tend to end up in the crucible in large amounts.
I guess this is why the Lid and the quartz tube were invented.
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Oscilllator
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| Quote: Originally posted by aga | The major problem with charcoal or coke fuelled furnaces is the ton of carbon bits floating about due to the forced air.
Carbon bits tend to end up in the crucible in large amounts.
I guess this is why the Lid and the quartz tube were invented. |
Actually when I was operating my forge I did not have that problem at all as for most of the time the lumps of coke just stuck together and so there
was no visible particulate matter floating about. It was a different matter when stirring/agitating the coke however, as that did cause quite a bit of
ash to fly around. I often did away with my lid if the experiment did not require it, as they invariably cracked.
With regards for high temperature experiments I can heartily recommend casting aluminium, it's great fun. If you have a spare afternoon you could read
through the phosphorous thread (although there is a summation somewhere). You may also want to try making potassium dichromate through fusion of Cr2O3
and KNO3, which I hear works quite well.
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Bert
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Sulfur trioxide and Oleum production.
http://www.sciencemadness.org/talk/viewthread.php?tid=5495&a...
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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RogueRose
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\
Wow SO3 sounds like a pretty nasty compound! That is an interesting reaction though but I'm not sure I can justify working with that unless it was
needed as a last resort.
As to the issue with getting ash/carbon in the reaction vessel, I agree with that. I tried heating pulverized egg shells as I read that should yeild
CaO after heating to the temp I did (1600-1900). The egg shells turned a dark grey and were just barely glowing orange and some minor flames. The
shells do crush a little easier after this (mortar & pestal) and when I add vinegar to them I get a little bubbling as compared to none with
uncooked shells.
I do like casting Al, Pb and Zn! For those who haven't tried to work with brass, I find this stuff really tuff to melt, it's like dissapates heat as
fast as I add it and this isn't a large casting volume (1/2 - 1 lb) and the forge puts out lots of heat (IDK how many BTU, would be good to measure!).
Also, a nice alternative to cast iron is ZA27 which is a zinc/aluminum/copper alloy which is about 65-78% strength of cast iron but melts at like
~750 degrees (and casts well!).
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Pumukli
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I don't want to ruin the party but having a high temp capable forge is one thing (which I also wish I had).
You will probably need the appropriate vessels too to carry out some suggested reactions though! Generating SO3 sounds fun, but it may
require a quartz tube/flask/whatever besides the heat. Also, melting NaOH, dehydrating H3PO4, etc. will require different
flasks.
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metalresearcher
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Well, you are looking for a device generating high temp or a vessel withstanding high temps ?
The first (see also my website www.metallab.net with several furnace experiments up till 2800 C, MgO melting) can be achieved by:
- Propane / forced air heated furnace up till 1500 C
- Electric arc furnace using a welder, useful temps 2200 C (carbide making) and 2800 C in small quantities (MgO sticks melting like plastic)
The second: for me also a problem. Till 1500 C I use graphite crucibles to hold liquid cast iron, and refractory the same rating. The Blakite coating
I use melts before 1700 C. Suitable for propane but not in an EAF as the arc melts / vaporizes any refractory so it is strongly damaged after just one
use.
I am looking for MgO bricks but can hardly find any on ebay unless I buy from USA sellers who charge brutally high shipping costs.
Closed retorts are more a problem, a way to reduce Na an K metal by heating their carbonates with powdered charcoal to 1200 C succeeds, but I have no
way to capture the alkali metals as the steel retorts cannot stand temps over 1200 C and air comes in immediately burning the alkali metal vapors.
[Edited on 2015-11-7 by metalresearcher]
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