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Author: Subject: Production of crude calcium hydroxide using seashells
plante1999
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[*] posted on 21-5-2012 at 17:35
Production of crude calcium hydroxide using seashells


This is the version one.

I would like to know your opinion on this work, I worked quite hard to make it... I'm not native English speaker so I would like some help in this point. I you could help my for grammar mistakes please contact me on the U2U system.

please look at the latest post for the latest version of this document.

Thanks!!!

Attachment: Calcium hydroxide production.pdf (1.1MB)
This file has been downloaded 6028 times

[Edited on 22-5-2012 by plante1999]

[Edited on 22-5-2012 by plante1999]




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plante1999
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[*] posted on 21-5-2012 at 18:10


There is a mistake on the reaction of calcium chloride and sodium sulphate. In next version this will be changed.




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Magpie
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[*] posted on 21-5-2012 at 19:17


I like it. Good work.

Your grammar is good. I had no trouble understanding any of it. I would change "lime methanol" to "like methanol," however. You could also change "Somme" to "some."

I have made CaO myself several times but start with slaked lime, Ca(OH)2, from the "ranch and home" store. But I know you like to start with very basic raw materials, right from nature.

Many limestones are more or less dolomitic, ie, contain a significant fraction of MgCO3. I don't know if this is an issue with seashells, however.




The single most important condition for a successful synthesis is good mixing - Nicodem
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plante1999
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[*] posted on 17-8-2012 at 14:09


It seam that my version 1.2 was deleted at the same time as the spam.

There was 120+ downloads :(

As a side note there was in total of the two version 250+ download and only one reply, is my post so boring?

Attachment: Calcium hydroxide production V1.2.pdf (1MB)
This file has been downloaded 1500 times

[Edited on 17-8-2012 by plante1999]




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Vargouille
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[*] posted on 1-9-2012 at 05:00


"In fact when the blower of the furnace is turned off large amount of blue flame is made proving that the charcoal does not burn completely to carbon dioxide."

I believe you've got it mixed up. A blue flame indicates complete combustion, while orange or red flames indicate partial combustion.

It is interesting, though. I may try this myself, albeit with a propane torch and a crucible.
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barley81
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[*] posted on 1-9-2012 at 11:40


I think he meant this:
Blue flame indicates presence of carbon monoxide gas; therefore, the charcoal didn't completely burn to CO2 in one step (rather, it first produced CO gas).
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plante1999
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[*] posted on 1-9-2012 at 12:51


When the blower is on there is no flame but when it is turned off there is flames meaning an incomplete combustion to CO when the blower is on, but To CO2 when it is off, Blue flame indicate this. That's a potter trick too. (I don't do pottery).



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[*] posted on 1-9-2012 at 14:15


Ah, I see my mistake. I was assuming that the fire would always be in the visible range. Perhaps the answer takes advantage of this. While the blower is on, the increased flow of oxygen allows direct reaction of carbon to carbon dioxide, which leaves the system. Photon emission would be in the ultraviolet range. While the blower is off, decreased oxygen flow results in production of carbon monoxide, which ascends into a more oxygen-rich atmosphere, and due to the heat, combusts to carbon dioxide, releasing photons in the visible range.

Perhaps a more mathematically advanced chemist can point me to a formula to test this hypothesis?
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plante1999
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[*] posted on 1-9-2012 at 14:19


maybe you are right, But from what I read yellow-white hot carbon make carbon monoxide since this reaction happen readily at high temperature:

CO2 + C -) 2CO

Edit:

I found the reaction I was talking about :

http://en.wikipedia.org/wiki/Boudouard_reaction

[Edited on 1-9-2012 by plante1999]




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[*] posted on 1-9-2012 at 15:54


True, but in the industrial setup, how fast is the air circulation? If the CO2 generated from combustion is passed through carbon at too high a rate, it won't comproportionate into CO fully, and once it exits the system, Le-Chatelier's Principle applies. Moreover, in a blast furnace, the air pushed into the furnace is pre-heated to sustain the reaction. The carbon used industrially likely has a much higher surface area than the large charcoal pieces used here, which supports the production of CO in a blast furnace. When you switch the blower off, the CO2 expands through the carbon due to heat, leading to a much more intimate mixture than with the blower, and thus more CO production.
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[*] posted on 17-10-2012 at 02:06


Excellent, plante1999.

I suppose chicken egg shells or snail shells can be used instead. They may be more readily available for some people.
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[*] posted on 17-10-2012 at 14:07


when i used egg shells, it ended up leaving a lot of CaS in there, as evidenced by evolution of some very smelly H2S when i tested it with dilute HCl. maybe i did not heat it enough?
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