Sciencemadness Discussion Board

metaloxide + carbon

setonix - 22-3-2013 at 11:08

Hello evrybody,

I have been started to investigate the mixtures of metaloxides and carbon.
When you heat those mixtures they will combust and produce the metal and CO2. This is kinda like thermite only you form gas(CO2) instead of Al2O3 in powder form.

This is also something that doesn't burn as hot as thermite but still is interesting because it is not so safe to work with in high amounts of the mixtures. Because normally you heat the mixtures from below till it combust only the problem is that when you use a high amount of the mixture, that you don't see it start to combust and when you keep heating it the reaction will speed up with a result to make alot of CO2 that will be trapped under the uncombusted mixture on the top and that will give a sort of explosion when you don't slow down heating. So for the people who wanna try this at him be aware its a safe test you can do at home if you don't use too much.

I have already tested 2 mixtures alot where i can give alot of info about the rest i will talk about soon.

MnO2 + C => Mn + CO2
7.2g/1g
First test was with 4.1grams of the mixture, I heated it a bit and after a short time it ignited. It burned slowly with nothing trown out of the mixture and a clean burn( no CO formed) it glowed red by the heat.

second test was with 8.2 grams of the mixture, I heated it again but this took longer or atleast looked to take longer because there was nothing shown at the top. I measured the heat that was produced at the top of the mixture and at the temparture around 230°C the heat of the mixture rised alot but still nothing shown until a small second later particles where thrown out of the crucible and holes where visible in the mixture where you could see the heat of the mixture and the temperature went around 480 - 485 °C. the heat inside the mixture is higher but not measured yet.

2*Al2O3 + 3*C => 4 Al + 3CO2
this mixture was tested but wasn't so succesfull because there was formed alot of Carbonmonoxide (CO) wich isn't advised to make so i stopped experiments around this because this isn't very healthy.

The next mixtures i'm going to test are:
Fe2O3 + C
Fe3O4 + C
ZnO + O
BaO + C
BaO2 + C
PbO2 + C
CuO + C

If anybody got requests for some mixtures to try or want to know more about the tests or got advice for me, it's always welcome.

Mvg Setonix

DraconicAcid - 22-3-2013 at 11:46

Quote: Originally posted by setonix  

2*Al2O3 + 3*C => 4 Al + 3CO2
this mixture was tested but wasn't so succesfull because there was formed alot of Carbonmonoxide (CO) wich isn't advised to make so i stopped experiments around this because this isn't very healthy.[/rquote]

I have a very hard time believing that this mixture would have done anything, as this reaction has a very large positive Gibb's free energy of reaction. The Hall process for extracting aluminum from aluminum oxide uses this reaction, but has to put in vast quantities of energy (in the form of electricity) in order to get the reaction to go.

[rquote]The next mixtures i'm going to test are:
Fe2O3 + C
Fe3O4 + C
ZnO + O
BaO + C
BaO2 + C
PbO2 + C
CuO + C


I doubt that anything but the barium peroxide and possibly the lead(IV) oxide will be very energetic.

Motherload - 22-3-2013 at 18:33

I won't really consider most of them energetic mixtures.
It's a standard RedOx reaction.
That concept has be utilized for quite sometime to smelt metals from ores..
Iron being the most common one..
The mix of Fe2O3 and coal has to be heated to very high temp to get the reaction started and to the best of my knowledge not self sustaining.
Molten Al2O3 has to be electrolysed with carbon electrodes to produce the metal and CO2.

setonix - 25-3-2013 at 08:56

today i tested Fe2O3 and like it was said by motherload, the mixture reacted but the top of the mixture didn't reacted because there wasn't enough heat transferred by the ignited mixture to the top of the mixture.

Btw friday i willbe filming and testing atleast CuO,BaO2,PbO2 and maybe ZnO and BaO if there is enough time left.
I will post the videos and the results on this thread so evrybody can see them and maybe test at home or use them for themselve for something else