MadMat Posted May 29, 2021 Posted May 29, 2021 Adding to the danger of milling magnesium; even if it doesn't react with; "the oxygen in the air, any other metal oxides, from CO2, and even nitrogen." powdered magnesium can easily become pyrophoric. This means that the second you open your mill jar up the magnesium will instantly react with the air and start RAPIDLY burning. Hell, finely powdered magnesium can even react with water. I researched this some time back and found there are a few inert gases that could be used as a shield to mill magnesium but then you ultimately end up with pyrophoric magnesium. It just isn't worth the risk. I highly suggest not to try it.
ronmoper76 Posted June 3, 2021 Posted June 3, 2021 So how does one make a water dichromate? And a "passfire"? I would love any excuse not to explode. If this method really does powder magnesium it is very much appreciated. Thankspassfire is a subscription pyro website that has a lot of useful information. I forget the exact measurements at the moment but you weigh so many grams of dichromate to so many milliliters of water ,heat it till its dissolved and add it to so many grams of magnesium till it's evenly absorbed and then dry it. It's extremely poisonous but if that doesn't scare you,it's a pretty simple process. I nailed it the first time with ease,other guys on here can explain it much better.
SharkWhisperer Posted June 3, 2021 Posted June 3, 2021 passfire is a subscription pyro website that has a lot of useful information. I forget the exact measurements at the moment but you weigh so many grams of dichromate to so many milliliters of water ,heat it till its dissolved and add it to so many grams of magnesium till it's evenly absorbed and then dry it. It's extremely poisonous but if that doesn't scare you,it's a pretty simple process. I nailed it the first time with ease,other guys on here can explain it much better.Dude, that's passivating already milled powdered Mg, not a way to make Mg resistant to firing up during milling. Dichromates of any type are super toxic (carcinogenic) and need to be used with care Teating Mg powder with potassium/sodium/ammonium dichromate and letting it dry out is standard stuff. But if you passivate it with dichromate and then go mill it again, well, the protection was only surface-deep, and is then gone. Mg powder is going to react with atmospheric oxygen, eventually, no matter what. With milling, only atmospheric O2 is the concern (not CO2, and especially not N2, MadHat ya friggin' idiot, ffs). The idea of milling with the jar (airtight?) flushed with nitrogen or some expensive rare gas (argon...) is only practical in large commercial batches. No matter what you do, that Mg will strive to and eventually become oxidized to gain an MgO coating. When ball-milling Mg on a hobbyist scale (and why the hell would you bother in the US when you can buy the stuff cheap?), "burping" the jar every few hours to let oxygen in and react with the Mg surface in a controlled fashion instead of all at once, is the standard way to prevent an unwanted ignition. It's going to oxidize eventually, between milling and building, ffs. It's simply controlling the speed that occurs at so it doesn't superheat and ignite. That said, if you have a commercial source for Mg (in the US there are many, and many grades; affordable, too), then why the hell would you risk burning down the house??? Milled Al has similar cautions but is not quite as pyrophoric as Mg when the mill jar's opened to fresh air.
MadMat Posted June 3, 2021 Posted June 3, 2021 I'm a friggen idiot? I never said anything about nitrogen or carbon dioxide. Check your reading comprehension, I was quoting the post directly prior to my post. Do you know what quotation marks mean? I was making the point that magnesium is highly reactive and for all practical purposes beyond the abilities of the guy at home
MadMat Posted June 3, 2021 Posted June 3, 2021 Oh yeah... FYI maybe not in a mill jar, (I say maybe not because I simply don't know for certain) but magnesium will react with both nitrogen and carbon dioxide. Magnesium will actually burn in an atmosphere of pure carbon dioxide, and also nitrogen dioxide; no oxygen required The products of these reactions, respectively, are magnesium nitride and magnesium oxide + carbon. So next time you want to play know-it-all make sure you know what you are talking about.
SharkWhisperer Posted June 3, 2021 Posted June 3, 2021 I'm a friggen idiot? I never said anything about nitrogen or carbon dioxide. Check your reading comprehension, I was quoting the post directly prior to my post. Do you know what quotation marks mean? I was making the point that magnesium is highly reactive and for all practical purposes beyond the abilities of the guy at homeNo. amigo, you are perhaps not an idiot. You're might even be a friggin' genius. Now that that's settled, you quoted an "I'm an idiot" phrase about CO2 and N2 being oxidizing influences on milled Mg. Pure genius. Reader will decide.
SharkWhisperer Posted June 3, 2021 Posted June 3, 2021 (edited) Oh yeah... FYI maybe not in a mill jar, (I say maybe not because I simply don't know for certain) but magnesium will react with both nitrogen and carbon dioxide. Magnesium will actually burn in an atmosphere of pure carbon dioxide, and also nitrogen dioxide; no oxygen required The products of these reactions, respectively, are magnesium nitride and magnesium oxide + carbon. So next time you want to play know-it-all make sure you know what you are talking about.And next time you need to pontificate on your grand knowledge, then be ready to back it up. Somehow, you switched from "nitrogen" to "nitrogen dioxide". How convenient. And regarding practicality and your nitrogen "dioxide" statements, why the hell does this kid considering milling Mg give a rat's ass about interactions with nitrogen oxides, ffs??? Or was that N2, hmm? Twit. Not much worse in my books than a semi-bright dimwit spewing "knowledge" about chemical reactions that changes as his knowledge base evolves, within minutes as he furiously googles away. Ass, that is dangerous. You got a dude milling metals here, and you want to 1) spew nonsense about N2 (WAIT, that's not what I meant!) being an oxidizing agent (fool), and 2) not giving practical advise. DUDE: If you're milling metals (and I wouldn't unless that was for some reason my only source) then burp them every hour or so to expose them to atmospheric oxygen. So it doesn't happen all at once when you finish. And be careful (per Madman) about all of that reactive...ooooh....nitrogen...that happens to be most of air. Actually, it won't do jack-squat. It's oxygen you need to focus on. Edited June 3, 2021 by SharkWhisperer
MadMat Posted June 3, 2021 Posted June 3, 2021 OMG what does this say??? "even if it doesn't react with; "the oxygen in the air, any other metal oxides, from CO2, and even nitrogen..." Does that say, in any way, say that I agreed with the statement?? Again, you either have a serious reading comprehension problem or you're just hunting for something to make a shitty comment about. I said magnesium reacts with nitrogen and yes it damn well will. Ask an experienced welder sometime if he would use nitrogen as a shield gas for magnesium. what I did say is that magnesium will actually burn in an atmosphere of nitrogen dioxide without the presence of any oxygen
MadMat Posted June 3, 2021 Posted June 3, 2021 That was shear genius of you telling the guy about "burping" the mill jar occasionally to prevent the formation of pyrophoric magnesium. It seems that everyone on here has been telling the guy NOT to try ball milling magnesium at home. You even say it, then you tell him about a procedure that could possibly make it safe... And you have the balls to say what I posted was bad for him... Pure genius
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