setonix
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Chromium thermite
Hello evrybody,
I have been working on making chromium themite but without any succes. Now i wonder if i could get help from anybody. I have made a chromium thermite
mixture with 2.8g of Cr2O3 and 1g of Aluminum powder. when i tried ignition with a magnesium ribbon i ahd no succes then i used potassiumpermanganate
and glycerin also no succes so now i'm searching where my error is. Can it be that my aluminium powder isn't fine enough because in the mixture i can
see the aluminium particles. please help me.
PS: tomorow i will post some photo's and maybe video's after a second try.
Mvg Setonix
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Motherload
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What are the sources for your materials ?
"Chance favours the prepared mind"
"Fuck It !! We'll do it live !!"
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setonix
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the Cr2O3 comes from the reaction of K2Cr2O7 with heat and that gives K2O and Cr2O3 and i have no idea where the K2Cr2O7 comes from
the Al powder is also unknown source its a very old bottle thats the only thing i can say. I received the ingreadients from my school they had them
still stored so its from something very old. My teacher said that he never ordered the materials so thats 20-30 years ago.
The Al powder is not really a powder there are small and big shiny pieces in the container so do i maybe need to filter it or make them smaller before
using?
I will upload a picture of the containers tomorow when i can get a picture of it.
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setonix
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ok i got the pictures. Btw friday i will test another made mixture of Al and Cr2O3 if that doesn't work i'm switching to another metaloxide. Now i
want to know wich metaloxide you prefer the best for me. I want to have not a too fast burning and a too hot reactive but a nice burning without to
much debree trown away from the reaction.
I found 2 large containers of MnO2 and Fe2O3 and some smaller bottles with metaloxides.
http://imageshack.us/f/694/20130318161710.jpg/
this is my Al powder is it ok?
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Heuteufel
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You are using much too small amounts. For goog results (if you want the metal) use never less than +-100 g of thermite mixture. Here a recipe for Cr
from the german book Jander/Blasius (Jander/Blasius Lehrbuch der analytischen und präparativen anorganischen Chemie). 70 g of dry Cr2O3 + 25 g of
molten and powdered K2Cr2O7 + 25 g of Al-granules (fine granules, but don´t use Al-powder, or the reaction tends to be too vigorous!). Put 10 g of
CaF2 on the bottom of the crucible. Use 10 g of (3:2) Mg-powder/BaO2 for ignition of the mixture. Make sure all reagents are dry!
PS: Making Cr2O3 from the dichromate is a waste of good dichromate. Buy it. 
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setonix
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ok this will help me greatly but is it also so for the other reactions like Al/Fe2O3 and Al/MnO2 ?
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Metacelsus
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Yes. Generally, you need at least 50-100 g, depending on how energetic the thermite is. For example, copper needs less than iron.
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Motherload
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That aluminum powder looks like sand.
"Chance favours the prepared mind"
"Fuck It !! We'll do it live !!"
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setonix
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is it good that my aluminium powder looks like sand?
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elementcollector1
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Probably.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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