Destruction of paper

[tentacles]

TS: That's kind of my point, too. Anyone who're tried to burn a phonebook knows it's not so easy to burn a stack of the stuff.. 2 to 3 cu ft is a lot of (potentially?) sensitive documents to have just sitting around in hardcopy. Seems it would be MUCH more secure to have them in an electronic format - and easier to destroy. A SSD or HD would take mere moments to destroy with a bit of hot thermite, explosive, or a microwave (in the case of SSD).

 

Perhaps paper made of celluloid. THAT would burn quickly indeed... Or there's the other option, of "burning" it VERY quickly.

[Rooster]

Well, changing the type of paper(ie. celluloid) in all the archives back to the 1950's is not an option. I know it is a lot of paper, but thats what I've been given to work with... I think if acids should be used, it would have to be something oxidizing like piranha fluid. I still have problems visualizing this eating through this stack FAST though. Probably the easiest is a thermite grenade or a big container of thermite in an insulated box(preferrably outside). I imagine the heat produced here would destroy most of the paper, and char the rest so that it could not be read. Also you solve the problem of oxygen supply, you could just raise the amount of oxidiser a little, to account for the additional paper. I dont really think it is too easy to get much out of paper ash/iron-charred paper mixture.

 

So lets go for thermite then. What types of thermite burns slow enough and releases the most heat(there must not be a chance of an explosion)? Iron Oxide/Coarse Al would be my bet, the copper types burn too fast. Any other that burn hotter but are not weirdly expensive? Vanadium/oxide rings a bell, but I could be off my rocker.

[Miech]

Chromium(III)oxide with aluminium burns hot and not too fast, or titanium oxide thermite of you want a *very* high light output. You might want to test it first by trying to burn through a phone book.

[Mumbles]

You'd have to look up the enthalpy of formations for the hottest one. The oxide with the most postivive enthalpy of formation will release the most heat. Manganese comes to mind. I also like the idea of sodium oxide, a very cheap product on the industrial scale for it's use in creating glass. It would release sodium metal theoretically which would continue to burn after the thermite, though there is probably a chance for explosion. Perhaps silicon dioxide is another choice, also very cheap, as it would release molten silicon, which would insulate the heat and continue the burn, though perhaps preserve some of the documents.

 

You could always take to nitrating all the old documents to convert to celluloid.

[FrankRizzo]

Even with a thermite grenade, all the molten metal does is raise the temperature of the paper to the point of ignition. You still run into the issue of the available oxygen inside the container and the surface area of the paper being exposed to the heat. Even if the container is "leaky", you are limited by how fast new oxygen can diffuse in while combustion byproduct gasses are vented. A source of pressurized oxygen, vented into the container after combustion has already started, would serve to spread the pages apart exposing more surface area while also replenishing the atmosphere inside.

 

 

Here's some Goldschmidt reaction data for the best candidates (gram-per-gram of mixture):

 

Manganese Dioxide

3MnO2 + 4Al --> 3Mn + 2Al2O3 + Heat (4.851 kJ/g)

 

Copper Oxide

3Cu + 2Al --> 3Cu + Al2O3 + Heat (4.584 kJ/g)

 

Vanadium(V) Oxide

3V2O5 + 10Al --> 6V + 5Al2O3 + Heat (4.57 kJ/g)

 

Iron(III) Oxide

Fe2O3 + 2Al --> 2Fe + Al2O3 + Heat (3.985 kJ/g)

 

Iron(II,III) Oxide

3Fe3O4 + 8Al --> 9Fe + 4Al2O3 + Heat (3.677 kJ/g)

 

 

Although manganese and copper release much more heat energy gram-per-gram, the iron oxide reactions are still the best solution. The reason is that the products are *LIQUID* at the reaction temperature, and are able to *conduct* their energy directly to the material being destroyed. The others vaporize their products and heat the air...and we all know how good air is as an insulator. Also, heating the air too strongly usually leads to explosions.

Edited October 7, 2008 by FrankRizzo

[TYRONEEZEKIEL]

If you are able to stir the papers around before you destroy them, try mixing the thermite around with the papers and then adding more thermite on top?