Nikko Posted January 18, 2015 Posted January 18, 2015 Hi all. I'm sure we all know that different charcoals have different effects on compositions. My question is why? The carbon surely is the same, except for perhaps the texture, which I feel is homogenised by the milling. That leaves the various chemicals that are left in the charcoal. Calcium Carbonate, Calcium Oxide, Iron Oxide, Potash and various phosphates. Anyone able to provide me any more information on this topic? Or am I barking completely up the wrong tree.
Nessalco Posted January 18, 2015 Posted January 18, 2015 Start here http://www.fao.org/docrep/x5555e/x5555e03.htm#TopOfPage The entire article is interesting, but this page talks specifically about the retort process and the chemical composition of charcoal. I suspect the biggest single factor affecting performance is density of the pulverized product. Sumac and willow charcoals are very light and fluffy. Oak charcoal much less so. Kevin
Arthur Posted January 18, 2015 Posted January 18, 2015 First look at the physical size of a mass of charcoal -they vary in density according to the wood used so charcoal is a porous sponge like material that you can push things into. Second note that charcoal is cooked at moderate temperatures (300 - 500C) so there will be some heavy organics left in there -in fact clean dry carbon makes really DUD BP. From one of the better chemists I know " Charcoal is not considered to be C, but C7H4O " Remember that we use "Charcoal" and NOT carbon.
Zumber Posted January 19, 2015 Posted January 19, 2015 Hi all. I'm sure we all know that different charcoals have different effects on compositions. My question is why? Lightwood charcoal is light in weight because its more porous and due to its porous nature other particles fits in this charcoal pore (when we homogeneously mix the composition) and hence composition burns faster with light charcoal eg Balsa wood.Hardwood charcoal is less porous than lightwood charcoal and hence composition burns slower than Lightwood charcoal, such charcoal is used in charcoal tailed stars to get last long spark. Eg pine in tailed stars.
Nikko Posted January 19, 2015 Author Posted January 19, 2015 Thanks guys. Some excellent info here. Now that I'm on a larger property, once the weather cools down a little (total fire bans at the mo) I will actually be able to make some comps!
spitfire Posted January 19, 2015 Posted January 19, 2015 Like Arthur said, there is a huge difference between charcoal and chemically pure Carbon. A diamond is pure carbon, but you won't be able to make BP with it. Or with Graphite. Neither with coal used in powerplants. It's the structure that matters a lot, with several other pinpoints not everybody agrees on. Talking with pyro's on charcoal is like talking to devoted wine drinkers!
FlaMtnBkr Posted January 19, 2015 Posted January 19, 2015 Actually someone on Passfire made some BP with diamond grit made for lapping I believe. It wasn't anything impressive but it burned ok if I remember right. I've got 2, 18 carat bottles of 1 and 0.5 micron diamond spray made for stropping knives and razors. It wasn't too expensive (less than $30 for both) and it's a high end product that is very accurately sized (I think with modified blood testing equipment interestingly enough). So I bet there is unsized stuff that is quite cheap considering it's diamond. Not that I'm advocating it's use, just that it wouldn't be insanely expensive to make a little. Would kind of be like the 'cigarette papers' made of gold foil. Yes, they exist.
Arthur Posted January 19, 2015 Posted January 19, 2015 Search youtube for Royal Institution lectures, Science of fireworks and science of explosives, presenter Chris Bishop. He's a great guy and a Cambridge University Professor in a red labcoat. One of his screen shots is an electron microscope image of charcoal, It's porous on a millimeter scale and a micrometer scale. Properly pressed powder has sulphur and nitrate pressed into the pores. also see
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