OldMarine Posted September 18, 2016 Posted September 18, 2016 I'm not sure why the argon isn't working but I'll give the silicon and charcoal a go. Nothing ventured, nothing gained.
WSM Posted September 18, 2016 Posted September 18, 2016 I've tried a couple of times since I got my new crucible. I bled argon in at low pressure and I may as well have been pumping oxygen in there. I haven't tried a flux yet but I'll give it a try along with the gas before throwing in the towel.I've got borax and lime to try. I don't know if they'll work for magnesium but I've used them with aluminum. I'm not sure about the borax (sodium borate, Na2B4O7-10H2O), but if I remember correctly, lime is calcium oxide (CaO) and might be reduced by molten magnesium to calcium metal. If you try it, I hope I'm wrong. Thinking about it, when you flowed the argon gas in, when during the process was it done? Also, at what physical level and the flow rate? I ask because I've considered doing the same thing for a long time. My thought about purging with argon involved admitting the argon slowly, from the bottom of the cold metallic pieces in the loosely covered iron crucible, and then retracting the feed tube to above the metals as the atmospheric gasses are pushed up and out, and then continue the VERY SLOW feed of argon as the heat is raised to the melting point of the metals. I haven't thought about the usual method of first melting the aluminum and then slowly adding the magnesium, in conjunction with my idea of purging with argon. I think the rate of inert gas addition would be critical, as a slow feed, low in the crucible, would push the oxygen and nitrogen up and out of the crucible; rather than stir it up and blow the air around, fanning a magnesium burn. I haven't done any of this yet, but I'm running it all through my mind to try to anticipate all the various problems that could be encountered; in an effort to be prepared in advance to deal appropriately with them. Gentlemen, I defer to those of you who have practical experience with the process. WSM 1
OldMarine Posted September 18, 2016 Posted September 18, 2016 I flooded the crucible with argon before adding any metals and kept a flow at 2" WC flowing in throughout the attempt. I'm thinking I should up the pressure a tad and step up to a 3/8" pipe from 1/4" along with using some type of fluxing agent. I've scratched lime and borax from the list of possibilities and will research a bit more before trying again.
OldMarine Posted September 18, 2016 Posted September 18, 2016 Okay, I did a little experiment. I placed a small chunk of dry ice in my crucible and replaced my stainless lid with a piece of plexiglass. I turned on my argon at the 2" WC as I had used before and watched the CO2 vapor through the lid. Surprisingly even at that low pressure there was enough turbulence to cause a draft of air into and inert gas out of my lid. I have no way to safely seal my crucible without risking explosion if rapid oxidation started so I think I'll keep dropping the pressure and enlarging the gas feed tube size to try to achieve a balance between gas volume and speed of delivery. Pretty fun stuff!
NeighborJ Posted September 18, 2016 Posted September 18, 2016 It's creating a venturi effect. I think 2" wc is too high, when I weld, I need to purge my pipe and once it is cleared I close the regulator almost all the way. I gauge the argon flow by unhooking the hose and puting it up to my ear, if I can hear gas it is too much. It's the hi flow rate which draws outside air into the chamber. 1
OldMarine Posted September 18, 2016 Posted September 18, 2016 Yeah NeighborJ, I agree. I normally deal with natural gas and welding pressures so went with what I knew. I've got to get my 100lb propane tanks filled before I can try again since I drained my grill tank playing today. The Sunday steak will be on charcoal tonight as it should be!
memo Posted October 17, 2016 Author Posted October 17, 2016 worked on making magnalium from turnings today and had some fun times and made about 500 grams. it is bit of work but very doable. i took a beer can and cut the top off, packed the turnings in the can then used a arbor press to compact and refill. do this until the can is as full as you can get it. crumple up about 12 inches of al foil and arbor press that on top of the turnings fold over the edge of the can, arbor press the edges down . the beer can should be solid . I am using a foundry and metal crucible. you need a cap that will fit loose on the crucible. weigh the can full of turnings and weigh out the same weight in al. melt the al. when the al is free flowing skim of any dross then put the beer can full of turnings in the crucible and cover. give it about 10 min take the cover of and stir. cover again for a few minutes. skim the dross. I have been pouring in a bucket of water or you can pour in a tin can and cover with charcoal. or use a tin can for a crucible. memo
OldMarine Posted October 17, 2016 Posted October 17, 2016 (edited) I still haven't refilled my propane tanks so I haven't played with it anymore as yet. Are you weighing everything at the beginning and after the process (including slag) to insure you aren't losing most of one or other of the metals? I lost at least 20% of something each time during my trials. Found guy on one of my other expensive hobby forums who has an arc furnace he says will do the job since he casts magnesium autoparts regularly. He said it heats the metals so fast and robs the oxygen before the metals can react. He said he'd post a video I could share so I'm waiting! Edited October 17, 2016 by OldMarine
memo Posted October 17, 2016 Author Posted October 17, 2016 my foundry is a cheapo powered with charcoal and hair dyrer, no I have not weighed before and after. there will be a bit of dross
NeighborJ Posted October 18, 2016 Posted October 18, 2016 OM, an electric arc furnace is definitely the way to go. I often work in many of Pittsburgh's steel mills, and it is amazing how fast those heat up the metals. When I find enough good quality mag, I plan on using graphite rods (air arc rods) as the electrodes. And my welding machine will provide the current to run them. It should only take a few minutes to heat and eliminate the flare up issues. In fact any arc furnace I've seen has an exhaust plenum to draw the fumes away, this should make the argon purge unnecessary. The electrodes can be had at any welding shop but they have a copper coating which can be peeled off before use to prevent any possibility of cu termite reaction. They also work as a cheap but dirty chlorate cell electrode.
WSM Posted October 19, 2016 Posted October 19, 2016 worked on making magnalium from turnings today and had some fun times and made about 500 grams. it is bit of work but very doable. i took a beer can and cut the top off, packed the turnings in the can then used a arbor press to compact and refill. do this until the can is as full as you can get it. crumple up about 12 inches of al foil and arbor press that on top of the turnings fold over the edge of the can, arbor press the edges down . the beer can should be solid . I am using a foundry and metal crucible. you need a cap that will fit loose on the crucible. weigh the can full of turnings and weigh out the same weight in al. melt the al. when the al is free flowing skim of any dross then put the beer can full of turnings in the crucible and cover. give it about 10 min take the cover of and stir. cover again for a few minutes. skim the dross. I have been pouring in a bucket of water or you can pour in a tin can and cover with charcoal. or use a tin can for a crucible.memo I like the low tech solution to the problems of using magnesium turnings to make magnalium. Smashing them together in an aluminum can to a near solid mass is simple and brilliant, for small scale runs. I imagine making several aluminum can magnesium "pellets" ahead of time can facilitate production for larger runs. Thanks for sharing the idea. WSM
WSM Posted October 19, 2016 Posted October 19, 2016 (edited) OldMarine and NeighborJ, Thanks for sharing the idea of using an electric arc furnace to make magnalium and casting magnesium metal. I'd like to know more about that. I have access to a large amount of magnesium turnings and converting them to ingots or directly to magnalium is an attractive notion. Let me know what you can about the details so I can try to duplicate the process (safely). Thanks. WSM Edited October 19, 2016 by WSM
NeighborJ Posted October 19, 2016 Posted October 19, 2016 (edited) WSM, I am unaware of any existing process to arc melt mgal, but I am certain it is possible and I intend to try. Most of the arc furnaces I've seen are used in a manner which helps to eliminate impuritys such as magnesium, with the use of an oxygen lance, and are done on an industrial scale. Many of the steel ladles have a capacity of 2-400 tons and are frighteningly impressive once those those graphite electrodes are lowered and energized. I believe the first experiment I'd try would involve a heavy steel laddle, approx 6" dia and would have a lid similar to a retort. Aluminum is normally welded with a hi freq welder but I think that a standard DC arc welder will work fine for smelting. The graphite electrodes can be lowered thru the enlarged vent openings and will arc thru mag and Al at the bottom of the ladle causing it to heat up without burning, as long as air is not introduced. After the electrodes are removed, the lid can be removed and slag (dross) can be skimmed off and poured. This is on my list of experiments but is NOT a proven method. When work and life slows down a little this is near the top of my list of things to try. If OM could add or change anything from talking to his friend, it would certainly be welcome and save me a lot of missed steps. I'd think that the collective knowledge of this forum can create a proven,working process. Edited October 19, 2016 by NeighborJ 1
memo Posted October 20, 2016 Author Posted October 20, 2016 i am doing this on a small scale and on the cheap, i have plenty of things to spend money on in pyro. I only need 10 kilos that will last a while. its kind of silly to spend big money on a process when many folks just need to call August. I don't have that option, it cannot be sent to me. so I make it
NeighborJ Posted October 20, 2016 Posted October 20, 2016 Memo, I suppose if you don't already have the welding machine this would be a financial impossibility. In my situation the welder is on my truck and the only things I'd need to make this happen is a source of magnesium. I do use mgal from August and an very happy using it, but being a welder by profession, I am interested in all forms of metallurgy. This project is alluring to me and is worth every wasted penny. I am curious, since you have experience with this, do you use graphite rods and what heat setting do you set the welder to? What is your crucible made of?
memo Posted October 20, 2016 Author Posted October 20, 2016 NJ my crucile is made from mild steel exhaust pipe, the foundry is low teck. chacoal with a hair dyer fan. the whole thing cost me around $20 memo
austar Posted November 15, 2016 Posted November 15, 2016 I think dagabu tried putting a pressed puck of turnings into molten al. he said that you should wear full leather because it would blow out of the crucible. with out having the right equipment to melt the turnings I think your screwed. I will be checking the scrape people for the mag or try and buy it if available. memo
austar Posted November 15, 2016 Posted November 15, 2016 When working with any molten metal one should alwsys preheat any additives, from the metal itself to the ladel. I have seen ppl try to use a cold ladel when pouring aluminum into molds and its not pretty. Molten metal everywhere after a very load bang.
stix Posted March 14, 2018 Posted March 14, 2018 Sorry, I can't find the post I saw about a week ago regarding using magnesium turnings for making magnalium. That particular post pointed out that adding the turnings to the already molten Al will just catch fire and burn the magnesium - a pointless exercise. However, near the end of that thread, someone said that they had success by first consolidating the Al & Mg in a pressed slug, then melted. I already have -325 mesh MgAl but there are some glitter compositions that call for coarser, ie. 80-100 mesh which I've found is very hard to come by. That's why I want to make some, it's also an interesting experiment. I have Mg turnings and access to a heavy duty screw press. So what sort of Al?, beer cans - I have a few Al foil, standard Al tubing etc. Also, the main thing is SAFETY. Are there any safety issues with highly pressing Mg with Al. Would a steel former cause an issue? etc. The tests will be small ones yielding around 50-100 grams.
memo Posted March 14, 2018 Author Posted March 14, 2018 stix ,a beer can works great . just don't use too much pressure. I use a al slug the same size as the beer can and a arbor press.. make sure you have a lid for your crucible to help keep the air out out.when melted and the dross cleaned out I pour into a 5 gallon bucket of water
stix Posted March 14, 2018 Posted March 14, 2018 (edited) Thanks Memo. So why not too much pressure? I would have thought consolidating the cut up pieces as much as possible would be better and less likely to catch fire. This will be small scale - the slug will likely be 25mm diam. and perhaps the same in height. Pouring the final molten metal into water seems good - I saw that one on youtube - dangerous though? Edited March 14, 2018 by stix
Arthur Posted March 14, 2018 Posted March 14, 2018 Do some research on fluxes for aluminium and magnesium foundry work. You pour into water to cause the product to form into small lumps so that it can go onto further processing easily and safely. BUT amateur ball milling of magnalium is NOT actually a safe activity, -it may burst into a very hot and destructive fire. Mill small quantities outside and remotely. Look up as many references as you can before you start to mill, get some decent PPE.
stix Posted March 14, 2018 Posted March 14, 2018 (edited) Thanks Arthur. I never said I was "ball milling" Magnalium or Magnesium or Aluminium or anything else. I'm talking about "pressing" small shards of magnesium and aluminium into a solid mass, then melting. If I knew the answer, then I wouldn't be asking. [EDIT] So, from memo's post above "pressing" is ok, but don't use too much pressure? This is the big question that I ask. Edited March 14, 2018 by stix
memo Posted March 14, 2018 Author Posted March 14, 2018 too much pressure will blow out the sides of the al can. the slug I just poured in a tin can that was smaller than the beer can. when full then folded the top over and pressed it again.
stix Posted March 15, 2018 Posted March 15, 2018 (edited) Ah, ok, thanks memo, much appreciated. Your method was the one I was referring to in the old post I read. Yes, I get it that too much pressure would blow the sides out of the can. Although that is very helpful, it does not address my issues regarding safety. As in, will pressing a small slug under "great" pressure cause a reaction - ie. possible ignition? Do some research on fluxes for aluminium and magnesium foundry work. You pour into water to cause the product to form into small lumps so that it can go onto further processing easily and safely. BUT amateur ball milling of magnalium is NOT actually a safe activity, -it may burst into a very hot and destructive fire. Mill small quantities outside and remotely. Look up as many references as you can before you start to mill, get some decent PPE. Thanks and appreciated Arthur. Is your answer cryptic? as in pressing Mg+Al together under great pressure is similar to ball-milling magnalium? If so, then I would appreciate a clearer response. I think if someone asks a question about granulating bp, then fair enough to point them to do some more research, but if someone clearly asks a question regarding SAFETY especially when magnesium is involved, then I think it is incumbent upon respondents to give a clear answer. That's one of the reasons I'm a member of this forum. But ok, fair enough, perhaps you didn't read my post properly? Thank you. Edited March 15, 2018 by stix
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