AzoMittle Posted June 2, 2016 Posted June 2, 2016 Could calcium carbonate have a purpose in a formula other than as a color donor? For example I've come across a 1# core burner formula that is listed as 91% Black Powder and 9% Calcium carbonate. Are they using the carbonate to slow down the BP, if so why not adjust the BP ratios to start with?
Mumbles Posted June 2, 2016 Posted June 2, 2016 I would assume it's a burn rate adulterant. Not all formulas are good formulas. It may allow for the use of commercial BP in rockets. If that were the case, I'd just add charcoal though.
AzoMittle Posted June 2, 2016 Author Posted June 2, 2016 (edited) Well that's what I figured would be the most obvious application except this is a propellant used in US army hand signal flares, and I can't imagine any reason they would need to add an orange tail. Here is the tech data sheet for reference: http://uxoinfo.com/blogcfc/client/includes/uxopages/Mulvaney_Details.cfm?Ord_Id=Y23 I was thinking along the lines of what mumbles said but that didn't make sense if they could just adjust the BP ratios, if they were using commercial BP that would make sense though. P.S. "not all formulas are good formulas", I agree, all the more reason to study them imho. That, and I like to collect all formulas, good or bad, provides a nice large data set to mess around with. Oh, and also found out while looking into this: if you go through a lot of eggs, you can clean them and grind up the shells to make calcium carbonate; broken up egg shells are also great for us gardeners, a ring of them keeps the snails/slugs off of tomatoes and other plants they like to munch on. Edited June 2, 2016 by AzoMittle
OldMarine Posted June 2, 2016 Posted June 2, 2016 We called those star clusters. They DO have a massive Orange tail going up that lasts a bit so choppers can find the landing zone. I could be wrong but makes sense! 1
lloyd Posted June 2, 2016 Posted June 2, 2016 Patrick,CaCO3 is commonly used as a burn-rate modifier in non-color stars. It cools and slows the combustion by the evolution of CO2. If there's no chlorine in the flame envelope, it won't contribute a lot to the color of the flame. (some, but not a lot) Lloyd
Mumbles Posted June 2, 2016 Posted June 2, 2016 Chlorine isn't important for the generation of the typical calcium orange/red to the best of my knowledge. Just like sodium relies on the atomic d-lines. Calcium has strong green and red lines, which combine to what we see.
AzoMittle Posted June 2, 2016 Author Posted June 2, 2016 Chlorine isn't important for the generation of the typical calcium orange/red to the best of my knowledge. Just like sodium relies on the atomic d-lines. Calcium has strong green and red lines, which combine to what we see. How is that measured? Using some kind of spectrometer? This whole topic/phenomena is called flame emission spectrum, correct?
lloyd Posted June 2, 2016 Posted June 2, 2016 Azo,In _practice_ (as opposed to theory), Calcium compounds still require some chlorine to give their 'best' look. It's absolutely true that both sodium and calcium do emit without the presence of chlorine. But their spectrum shifts, and becomes more pleasing to the human eye when there is chlorine present. Please keep in mind that frequencies shift when chlorine is in the flame envelope! Lloyd
AzoMittle Posted June 3, 2016 Author Posted June 3, 2016 (edited) I want to see the difference for myself. If I mix up two batches of the exact same basic calcium carbonate (or really apply this to any formula) with the only difference being the presence, or lack, of a chlorine donor, how would I do so fairly? For example, taking the formula from above just because it is simply two pieces (to keep things simple leaving BP as a finished piece instead of individual parts), which of the following--if any--would be the correct way to compare: Add above========91% BP09% CaCO3+05% PVC Subtract non-color donor===================86% BP09% CaCO305% PVC Subtract color donor================91% BP04% CaCO305% PVC Subtract equal parts===========88.5% BP06.5% CaCO305% PVC Add to total then scale to 100 (95.24% @ 105 parts)========================================86.66% BP08.57% CaCO304.76% PVC Edited June 3, 2016 by AzoMittle
lloyd Posted June 3, 2016 Posted June 3, 2016 (edited) Since the small amount of PVC has almost no (effective) fuel value, just ignore it. Lloyd Edited June 3, 2016 by lloyd
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