LuisThePyro Posted August 10, 2023 Posted August 10, 2023 Have 10lbs of 400 micron Ap fuel . I want it down to 90 micron , can a ball mill achieve that ? Im about to order my ball mill and rest of my kit . Any pointers will help thanks. If you have done this before please let me know .
Arthur Posted August 10, 2023 Posted August 10, 2023 First, please note all the incompatibilities involving ap and get a mill and keep it for one chemical only. If your need is moderate then maybe buying the right mesh AP would be cheaper/quicker/easier than milling your own.
LuisThePyro Posted August 10, 2023 Author Posted August 10, 2023 Gotcha, its sold out EVERYWHERE 400 micron was the best I could get . Will be milling it down to a fine powder thanks for the tip.
SharkWhisperer Posted August 11, 2023 Posted August 11, 2023 I'm guessing you're not building APCP motor grains and don't need "90" micron, just much finer than the grainy 40-mesh (400 micron) currently available in pound quantities in the US (you can buy any size in bulk). 90 micron is about 175-mesh so unlikely to screen separate with any efficiency (my screens stop at 100-mesh and it's a chore getting powders through them). As others have mentioned, and as other threads here have gone into in detail, AP can be milled so long as you take appropriate precautions with chem incompatibilities. One tidbit is that AP nominally at/under 15 microns is viewed as a high explosive in US laws, for good reason, but typical milling to 'dust' won't get you here. Also previously indicated, it's best to have a dedicated mill jar for AP, although I mill in a multi-use jar that's very well washed out between chems (and never sees chlorates) with no problem. Wash your media, too, obviously... AP is pretty soluble in water (around 200g/L at room temps) and isn't going to mysteriously hide out and ambush you if you use reasonable care. This isn't a recommendation, just a description of what works for me and my concerns and comforts. My mill jars don't have hidden nooks and crannies. Recall that AP (and any ammonium comps) don't do well with chlorates, ever. Nitrates (KNO3, Sr(NO3)2, BP) will form hygroscopic AN and risk failures--avoid priming with BP-like comps unless well-segregated (I just don't--too many other options), and usual care if fine reactive metals are involved. AP can react with Mg and MgAl if any moisture is around--looking at you acetone, even if Mg is passified with dichromate.
Arthur Posted August 11, 2023 Posted August 11, 2023 Back to your first post in this thread! You say "Ap fuel". If you mean fuel then it's already mixed and shouldn't be milled. IF you you mean Ap oxidiser then keep reading. Maybe it's worth doing a test with a kitchen blade blender (of your own!) and with a ball mill, see whether there is a better particle size distribution by either method. The material that the manufacturer had would have had a wide range of mesh sizes -they picked one for sale -probably they had a better market for other mesh cuts. When you start to change the mesh size mixture you may not get all of it in the size that you want.
LuisThePyro Posted August 11, 2023 Author Posted August 11, 2023 (edited) It will be for strobe rockets, i know I need to bring the partical size down to be able to press that into a 3lb rocket motor . Just wanted to see if anyone here has dealt with prepping 400 micron ammonium perchlorate for a strobe composition. Edited August 11, 2023 by LuisThePyro
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