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How can i make magnesium powder


goro20

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Using a file takes to long and the particles are too big. When i use sandpaper it sticks to the paper and there is a lot of contamination. I have 60 grams magnesium ingots. Does anyone know how to ball mill it then without it going pyrophoric? Edited by goro20
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I used my belt sander lined the area around it with kraft and put a piece of card board at the end of the belt to get it from not going back around the sander dumping the fine on the paper. a filter cloth on where the bag goes. there is a little bit of resido from the belt but not much.

Edited by memo
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Using a belt sander on magnesium at high speed would be a recipe for disaster.

 

Getting a decent variable speed 2x72 will set you back 'at least' 2 grand unless you build it yourself.

 

Too dangerous for my blood. Magnesium is a different animal altogether.

 

I'm sure someone who processes it regularly would be willing to help you out for a small fee.

 

Why not email a pyro supplier and see if a deal can be worked. If you can do flat rate shipping it may be worth it.

Edited by PhoenixRising
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  • 3 weeks later...

The guy who wrote the (literal) book on hobbyist ball milling managed to have magnesium go pyrophoric on him; he was really lucky and got away with just radiation burns, temporary blindness, and a destroyed mill.

Are you somewhere you can't purchase it?

It's my understanding that even rolling it with a heavy dose of stearic acid isn't safe; people advise ventilating every hour while milling but I'm still too sketched out by the risk.

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Won't Magaluminum serve your purposes? Thats cheap and safer. You can buy this on Amazon in small quantities and cheap! Don't waste your creative energy making 'stuff' that you can buy easily.

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I cant buy magnesium powder or magnalum powder so i have to make it myself. i still dont really understand how this pyrophoric thing. so why does it ignite? why? how can oxygen in the ball mill ignite it. Edited by goro20
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Look up "how to make magnalium" on google. Making Mg dust will just get you burnt.

 

Using a file takes to long and the particles are too big. When i use sandpaper it sticks to the paper and there is a lot of contamination. I have 60 grams magnesium ingots. Does anyone know how to ball mill it then without it going pyrophoric?

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I cant buy magnesium powder or magnalum powder so i have to make it myself. i still dont really understand how this pyrophoric thing. so why does it ignite? why? how can oxygen in the ball mill ignite it.

 

Magnesium (like aluminum) is one of those metals that reacts readily with oxygen in the air. Your big chunk of magnesium has a convenient layer of already-reacted magnesium oxide on the outside. When you scratch it, oxygen quickly reacts with the exposed metal and forms magnesium oxide.

 

Keep in mind, oxidation reactions are exothermic--they produce heat. That's really all that fire is--materials oxidizing and burning off whatever can be oxidized readily at the given temperature. (Fun fact: your body heat is produced by the mitochondria in your cells oxidizing glucose in order to produce the ATP that runs your cells--AKA Krebs cycle.)

 

Now, normally, the heat produced by the oxidation process on a big chunk of magnesium isn't nearly enough to heat it to its ignition temperature--hell, you can't even feel it. But then you throw it in a ball mill...

 

Hard metal balls knocking off tiny bits of pure, un-oxidized magnesium. Smaller and smaller bits. Ever notice that you can heat a sewing needle up a lot quicker with a lighter than you can heat a nail? Well these tiny bits of magnesium need far less energy (in the form of heat) to hit their ignition point. And eventually, your milling gets them small enough that the oxidation reaction produces enough heat for them to ignite. And that one itty-bitty particle igniting produces more heat, and you get a nice chain reaction, a blinding flash (with bonus thermal burns on uncovered skin!) and a smoking crater where you ball mill once stood.

 

...and a lot of uncomfortable questions, some of which may come from people with badges.

 

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Edited by cevmarauder
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so basically the balls in the ball mill cause a lot of friction and that turns into heat which then ignites the mangesium powder. now what if you place your ball mill in a ice bath. no jk. but the belt sander doesnt even sound like that bad of an idea. i was planning to use a drone motor and attach like some kind of sandpaper to it. and then hold the magnesium in place with some metal. Edited by goro20
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Dude, just stop already!

 

When you knock the passivating coating off of Mg like that, it reacts to O2 and likes to start on fire. If you eat all the O2 up inside the ballmill when milling it, you will get a face full of Mg fire when you open it up. It's just not safe.

 

so basically the balls in the ball mill cause a lot of friction and that turns into heat which then ignites the mangesium powder. now what if you place your ball mill in a ice bath. no jk. but the belt sander doesnt even sound like that bad of an idea. i was planning to use a drone motor and attach like some kind of sandpaper to it. and then hold the magnesium in place with some metal.

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  • 5 months later...

I stayed in my house reading the forum and I was very worried how I could explain how the process occurs, to avoid an accident with you and with many who still do not understand how the process of oxidation of the powdered metals occurs. I will try to explain you in a different way: In nature reactions also happen in reverse order. If you heat an iron bar, there will be vibration of the atoms that will generate heat, so if you hammer this bar or rub it on the emery, you will also stir the atoms, which will cause heat. When we heat the water the molecules vibrate and is produced heat, so when we put the water in the microwave we produce vibration of the molecule, which causes it to warm up. So does the powdered metals. All heating generates oxidation, so all oxidation generates heating. If you take iron 400 mesh powder and heat it, you will have rust or iron oxide, so if you throw water with cooking salt into the iron powder you will cause oxidation and heat. If you put fire in Mg powder, you will have Mg oxide, so if you throw water with salt in Mg powder, you will have magnesium oxide and heat. What happens when we open a ball mill with a fine Mg (without protective layer) inside it, is that all dust oxidizes (heats) when it comes into contact with oxygen. And because the particles are very small (like the excellent explanation of the cevmarauder in this post) they heat up faster and ignite. Any questions?

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  • 7 months later...
I milling 350gr Mg 3 days now in ball milling 6" jar with 72 optimum rpm with half inch stainless steel balls media and i open it every 2 hours precise! The powder is begin to stick to the jar so i suppose it becomes ready to take it out! from 30 gramms pass inside from 325 mesh screen the 25 grams! And this procedure i make it over 20 time's to make mg dust. And my quastion is, why anything doesn't happen to me? Am i make it something wrong ? Maybe i got lucky over 20 time's? No. I JUST BE CAREFULLY WITH THIS DEMON! 1st when you milling a metal powder take precautions wich mean protective gear( welding rob, welding mask (electronic) firemen lether gloves) when you open the jar! !Every time! Second you only grinding with stainless steel ball bearing media wich is non sparking. Third the jar must be big to contains a lot of oxygen until you open it the next time avoiding exothermic reactions like go pyrophoric the powder when you open the jar and contacts with air ! And last more important thing you never ever milling in moisture Environments! Metal powders have the ability to be very "angry" with moisture and beginning to rusting rapidly and make exothermic reaction which means heat wich mean fire wich mean the hell it self! I hope i help sombody here!
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  • 1 year later...

I have half a kilo of Mg shavings, which I turned into small chips in a blender. I am going to make it into powder in a ball mill with steel balls. Because I have read about its pyrophoricity, I am going to have the mill running outdoors. Also, the lid of my mill has a 10mm hole in it which I normally cover with tape, I think I can easily aereate it by opening the hole for a couple of hours at a time, perhaps turning the mill a little once in a while. I might even leave the hole completely open, and tilt the mill, which is rather long, so that the hole end is elevated, allowing continuous venting. My question is, I read that one can passivate Mg powder with linseed oil. How does one do that? Would it be possible to add the linseed oil to the mill during the milling already, instead of after the milling is done? How much oil? Are there other substances that one could use?

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