Making Aluminium (The Hall-Heroult Process)
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- เผยแพร่เมื่อ 13 มิ.ย. 2024
- After recently buying an electric furnace, we now have the opportunity to try electrochemistry with molten ionic salts. This opens the door to making a whole bunch of exciting new things, such as sodium, potassium, lithium, calcium, magnesium, and many more.
To start off with, in this video we have a go at one of my favourite chemical reactions of all time, the Hall-Héroult process for converting aluminium oxide into aluminium metal.
Mixing our aluminium oxide with cryolite to reduce its melting point to 1000C, we melt it and electrolyse the molten mixture in order to reduce the aluminium ions into the metallic state on the cathode. It takes us a few tries, but we ultimately obtain 80 mg of the metal (which is a terrible yield, but at least it worked to some degree).
Keep in mind, this is a stupid way to obtain aluminium in a home setting, but it's interesting to explore the process nonetheless.
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Hey, just saw your video, and discover your channel. I am an electrochemist, with quite some experience with aluminium smelting, even if I'm not only doing that (unfortunately I cannot share videos of the inside of a cell). If I may, some explantation on how and why your yield might not be super great.
-First, you are very likely using pure Na3AlF6, thing we don't do. We actually use a mixture of Na3AlF6, AlF3 and some other components to reduce the melting temperature. Basically the yield fall with the temperature, and the coldest you are, the better it will be.
-Second , we don't feed all the alumina at once. Alumina solubility in cryolite is only around 5-8% and above that you will just increase the viscosity of your melt and create a sludge at the bottom, which is far from being ideal.
-Third, your setup. Your anode is way too small for your cathode. Usually only the bottom of the cell is conductive, the walls being shielded with non conductive material ( might not possible at your scale and considering you have no access to professional equipment), we start with some aluminium at the bottom, which also help, and finally, the ratio anode/cathode is as close as possible from 1, we even try if possible to oversize the anode for small scale devices in order to have as much voltage displacement on the cathode as possible
The last point is more safety related. Be carefull, cryolite is rather toxic, can expose you to fluoride, and then lead to fluorosis, on the top to expose you to Co and CO2. Try to not manipulate it bare hands when cold, and don't breath the fumes while molten.
It will sound like a lot, but I really liked your videos ( because I couldn't help but watch some others) and will follow your work starting from now.
Keep doing great stuffs, and cheers from the other side of the planet
I do plan on trying this again some day, so I'll definitely be taking this advice.
Thanks a lot!
To add to the third point, the current density of the anode is critical to ensure aluminium is actually being produced and you are not just making CF4/C2F6 which is known as an anode effect in molten electrochemistry. Too high anode current density produces this phenomenon and prevents the production of aluminium metal. I recommend having a constant current setup and monitoring the resulting voltage. High voltage spikes means you have an anode effect on your hands
Pot line engineer here: getting a high current efficiency is quite difficult but note that we also add extra aluminiumfluoride to the bath to increase the acidity and lower the operating temperature to 960 c. Also back reactions are quite common and the efficiency also largely depend on temperature stability.
This is awesome! I don't think I've seen anything like this on TH-cam, and I watch ALL the science and chemistry channels.
Pk
You can use an angled mirror to look into the melting pot without melting cameras! Great video by the way high temp chemistry is something you don't see often .
Adding excess AlF3 not only lowers the melting temperature, which helps make the bath more liquid but also directly helps current efficiency since the species that gets reduced to aluminium metal in the half-cell reaction is AlF3 itself (a bit simplified)
You are a truly extraordinary person, and I would like to thank you for your great effort in providing information in a practical way. You help me understand the difficult topics that I suffer from.
I used to work in primary aluminum smelters and I think it's really cool what you're doing. Since the aluminum sinks to the bottom of the pot, one thing you you could consider doing is letting the entire melt solidify in the crucible. It might cost a crucible because you might have to break it to get the aluminum out, BUT all the aluminum should be in one easy-to-recover piece at the bottom of the pot to verify how much you actually produced.
I would keep the power ON and do a valve in the bottom and pour out the aluminum every few hours
I'm pretty sure his issue is that he's mixing the purified aluminium into the solution when he pours it out. He's also introducing it to the oxygen in the air.
Fantastic! I know a bit about that process and it's not something I imagined anyone ever attempting at home. The HF scared me off 😅. So impressed you had the guts to have a crack at it and actually pulled this off.
I just discovered your channel today. Loving the material and great to see another Aussie making cool content! 🦘
Hall & Héroult would have be very, very proud of you!
this electro chemistry changed the world we used aluminium to make planes and we rely on it in every day machines. great channel just subbed after seeing a few other vids love the science bro
I'm hoping this being a unique vid makes the channel blow up so you'll upload more content. :D
Haha, me too. We'll have to wait and see :)
@@ScrapScience hi sir can i got ur number pls
@@ScrapScience i need some help
Right? This dude does awesome shit and I love how alot of the stuff he does can be done by anyone just by following his directions , I hope this guy blows up he deserves it I see channels not even on this guy's level getting up there on subs when people see him it's gonna take off
Saw references to fluorite being used in addition to Al2O3 and cryolite, I presume as a flux. Maybe that'd be a key factor? Also, maybe pouring into something deeper where it could also cool more slowly might help separation?
Great stuff, love the channel.
Lovely experiment, well done! Many volts were probably lost just running through the long and thin lengths of carbon rods, so the actual voltage was probably much lower (maybe too low?). This is probably why the industrial ones are short and stubby prisms. You need a power supply capable of delivering much higher current though because I suspect that without that resistance (of the rods), the current draw would be very high :(
I don’t think that’s the problem (though it makes the setup inefficient), the current is what matters for the yield, and if the voltage was too low, no current would flow as it wouldn’t be able to overcome the redox potential.
If you use large area electrode plates you would get mush better results
Awesome video. Thanks.
Interesting to see this reaction performed in an amateur setting. As you mentioned, it's not something that a many people have documented in video.
I think that the biggest problem is the viscosity. The ions may have it difficult to migrate from the solution to the surface and viceversa. Consider som kind of agitation, if it is feaseble.
I hope you become more popular because what you do is incredible at an amateur scale (I'm amateur too btw).
Great Video!
Very nice video! Besides so sodium production by electrolysis, I also did not seen any high temp electrolysis.
It is possible that this amount of Al was too small to separate nicely from slag. Probably it would be good to pour it into some cone shape, heated mold (like the ones used on mbmmllc channel). This way it would give more time for separation.
Also, it would not be possible to just dissolve slag in something? Wikipedia says AlCl3 solution should work. But I suppose cone shape mold is a better bet.
In the worst case, you can add a known amount of Al to the mixture (or other collector metal) to catch dispersed metal from slag. As a method to show how much was produced would be enough.
It seems like this is just an old chemistry curse: what works well on big scale, is problematic on small scale and vice versa. Can not wait for future videos!
I considered dissolving the flux away, but the idea of having soluble fluorine compounds turned me away from that idea very quickly.
I also thought about adding a bunch of aluminium to collect all the tiny pieces, but I worried that this would be difficult to properly measure, since some of the aluminium will probably oxidise as it mixes with everything. Additionally, it seemed a little less exciting to have our product mixed with some aluminium that we didn't even make ourselves.
I like the cone shaped mould though, that's a good idea. Maybe pouring it into a mould and introducing some agitation while it's still molten could help the beads coalesce?
And you've got my thoughts exactly! It seems like this process is simply something which is not made for a small-scale demonstration.
@@ScrapScience It is possible that for such small scale, some additional flux should be added to make coalescence of Al droplets easier. Maybe some borax and higher temperature? It is hard to say what will work, most informations are about less reactive metals like Ag, Cu, Au or Fe.
Hmm, that's not a bad idea at all. In general, cryolite itself is a very effective flux for most metals (including aluminium), but maybe adding borax or something will decrease the viscosity of the mixture a bit, and allow the metal to separate better?
The trouble with experimenting here is that every test requires nearly a full day's work, so trial and error is a very time-consuming process.
@@ScrapScience Just idea: maybe just melt cryolite with Al and see if it still makes problems. For separation protocol, you do not need to make full electrolysis each time. And when you have method for separation, then you make full process.
Just divide problem into modules, and then tackle them separately :P
Great work. I would, however, put some rock wool on top of the crucible to lower heat loss, and I would set the system to work at higher current intensity.
I've heard of expanded vermiculite being floated on the top of molten salt baths to reduce the heat loss. Not sure it would help with electrolytic yield though, just over all efficiency, and it could shield the air exposed section of the electrode a bit.
Interesting, that should be helpful for future experiments, thanks!
Hi sir can u help me to guide recover almunium from bauxite ore
@@amirshehzad5582 Not without it costing you more money than you could just buy the metal for. There is no way a small operation can be more efficient than a commercial refinery.
@@DanielSMatthews i have 60 percent allumina mine bauxite mine
@@amirshehzad5582 And you want to value add, that sounds like good business. But do you have access to very cheap electricity that is also reliable too?
you are a great teacher thank you still its a challenge and go for it lets see how to improve the the efficiency .
I agree with other commenters, you mixed the aluminum back into the cryolite when you poured it out, and the pouring likely oxygenated much of it back to alumina.
If your source for graphite crucibles could make you one which has a conical inside profile, tapered like a separation funnel, then you could allow the aluminum and cryolite to freeze in the crucible and still have a decent chance of getting them out of it. (Allow all to cool to room temp, invert crucible on heat-resistant surface, reheat the outside of the crucible with a hand torch to expand it away from the solid product cone, mechanically separate the aluminum tip from the cryolite bulk)
This utilizes the "aluminum denser than cryolite" feature, and keeps oxygen away from molten Al..
I know "custom crucible" seems like a big ask.. but there are still many machine shops which make custom, intricate graphite shapes for the "die sinking EDM" process - to them, your crucible would be an easy job.
I believe cryolite has the distinction of being Earth's only natural resource that humans have mined to exhaustion. Modern aluminium extraction uses artificially-produced cryolite.
Wow, interesting!
I was aware that the cryolite they use these days is synthesised, but had no idea it used to actually be mined itself. Thanks for the info!
Buen trabajo 💪👍
Slds cordiales desde Argentina 🇦🇷👋
Thank you for the great video. It is indeed one of the largest uses of electrochemistry. It is also one of the largest producers of contaminated waste, red mud. NaOH contaminated soil.
This is a real opportunity for a fundamental change in how this process is done at a core level so that all of the elements can be recovered, not just the aluminum.
Whoohoo you're back scrappy 😀🙏
Awesome！
I think I might buy one of those furnaces.
Wow I was expecting at least 120 volts I mean I just figured it would take more electric voltage and higher amps , dude this is awesome👍
Newcomer to the channel here. Never thought I'd find a chemistry channel that exactly suits my interests and, indeed, I do find it frustrating how little footage there is of many a different reaction that you have performed. So thanks for, uh, existing I guess. I'll be sure to stick around.
Great to have you along! If practical electrochemistry or scaled-down industrial chemistry is your thing, you're definitely in the right place.
In fact, if this is the kind of video that's to your taste, the next video I'm working on will probably fit your interests too, so stay tuned!
@@ScrapScience Electrochemistry is my thing, yeah, downscaling it to a home setting is just an added bonus. Sometimes I just like reading about the various chemical processes carried out by industry but then I get disappointed when all I can find is corporate videos selling products to carry out said processes. That or poor explanations in hindi from 10 years ago. So having an aussie Cody's Lab to explain all that crap and then show it to me sure is welcome.
The whole concept of Charles Martin Halls was explained briefly with logical reasoning in the intro itself,which we are not taught in school
Love from INDIA 🇮🇳 ♥
Very proud 😁
There's a good reason nobody shot such a video at aluminum plant. I've seen here a video of Discovery Channel Russia about an aluminum plant and why no one walks in there: while working through each of the forest of electrical rails run such a current that generates such a magnetic field that a heavy steal chain firmly hold from one end several meters from one such rail stays firmly parallel to the floor; imagine a camera attached to such a rail or near one.
Have you done any flow battery experiments the Ammonium Ferri/Ferrocyanide looks interesting?
Seems that you could fine tune the process a wee bit...
Also, it would make a lot of sense to sheath the anode with a high temp stainless steel straw, and keep re-feeding more Al2O3 stock to keep it moving.
I commend you for this attempt. Perhaps the aluminum plant will show you how the aluminum is extracted from the cryolite mix. Since you have an electric furnace you should try isolating sodium from sodium chloride with a plaster of Paris cell with a partition separator.
Here before the video explodes
Sodium from salt plz.
This it the best video ever.
I'll likely need to set up an inert atmosphere for that one. But yes, we'll be doing that in the future at some point. Stay tuned!
Using a conical mold to pour off your product would be necessary to coalesce the tiny metal beads. You probably got a much better yield. Pouring into that rusty old shovel was OOOF!
Excellent demonstration! Two questions: a) Could you use a quartz-glass tube, to imbed the graphite electrode in it and as such saving it from consumption in the parts above the cryolith molten solution ? b) continuously adding Al2O3 to the smelt, so that you would balance the production of Al ? Thx.
Great questions!
a) Kind of. Whilst it would protect the graphite to some degree, introducing quartz to touch the molten melt would result in some dissolving into the flux, and the dissolved silica would then prevent us from being able to make aluminium. It's for this reason that we couldn't use a silica crucible (in fact, silica crucibles were attempted by Charles Martin Hall in his original experimentation on the subject, leading to reaction failures).
b) Yes. This is how it's done industrially - as a continuous feed process. However, since we were only really making less than a gram here, it wasn't necessary for this experiment.
verry interesting 👍👍
and i love your crappy power supply in cardboard boxes😄
Is the cryolite reusable after the process, or does it get used up?
Is ist possible to make irom from iron oxide using electrolysis?
Haha, thanks!
The cryolite is not used up here - you can pretty much re-use it indefinitely as long as you add aluminium oxide to replace the aluminium that is extracted.
Iron is very tricky to make from the oxide in terms of molten salt electrolysis (it's still an active area of research right now), but dissolving the iron oxide in acid, and electrolysing the resulting iron solution is a method that works under the right conditions.
I was all like "hydrogen fluoride.... that name rings a bell... what is that?" Then I remembered!!!! No you don't want yo be huffing that!!! ;)
Neat setup. Was this stuff very expensive??
The furnace was rather expensive of course, though not nearly as expensive as I expected (a couple of hundred AUD). The aluminium oxide and cryolite were extremely cheap though (in fact, the shipping alone was around 5x the price of the chemicals).
@@ScrapScience Why did u get such a low yield was it the voltage and the temperature of the cryolite? Interesting.
I don't really have many ideas about what caused the low yield in the second run. It might be that the metal just didn't have time to coalesce properly, maybe I made the cryolite mixture too dense and the aluminium was actually floating and reacting with oxygen, or maybe I just couldn't find the globules of aluminium at the end. It might even be a combination of the three.
It shouldn't have been a result of the voltage or the temperature at least, since neither of those things should affect the reaction significantly.
I wonder if you would see a more reasonable yield if you were able to run the cell longer, if only from there being enough to actually pool together at the bottom of the cell making it easier to collect. I'm also curious if there's any solubility of aluminum in the cryolite mix. Even if it was extremely low, that could really cut into your % yield if your maximum expected product is only a few grams.
Congrats on making the aluminum though. I'm looking forward to seeing where you go next with the high temperature stuff.
I definitely would have liked to run the cell for a lot longer in order to get more product, since I agree that we would have got a much better yield if we made enough aluminium for it all to clump together properly. I just got a bit worried about running the furnace for extended periods of time like that (I don't want to break it in the first experiment I use it for). Additionally, I'm not able to supply anything more than 15-20 A to the cell, since I don't have a power supply capable of anything more than that.
The solubility of aluminium in the cryolite mix is something I hadn't considered though. Looking it up online, the solubility seems to only be around 0.1% by weight at 1000 C (which should have only subtracted around 0.1 g from the final yield), but maybe there's some other factor increasing its solubility.
@@ScrapScience Yeah, it looks like the solubility of aluminum wouldn't be getting in the way then. The only other thing I can imagine is that something relating to the operating conditions (like current density or maybe agitation) killed the current efficiency. Can't say I've ever dealt with molten salt electrochemistry though, those are just things I've seen get in the way of aqueous reactions.
@@ScrapScience From what I see, you seem to be using the 5V output from an ATX PSU. Maybe you could use some DC-DC converters to use the power from the other outputs? That should increase the current capability considerably and isn’t very expensive.
I would like to try this. Can you please tell me which furnace this is, where to buy it, and what power supply you used?
The furnace is a pretty standard electric crucible furnace (with a graphite crucible obviously). I don't recall the exact listing I got it from on Ebay, but you'll find hundreds of similar furnaces online if you search that term.
The power supply I used here was an ATX power supply from an old computer, simply because they're capable of 5V/20A. A voltage/current controlled lab bench power supply is also an option though (albeit with a somewhat lower current capability). Any DC supply with the capability of pushing more than 5 amps at around 5 volts DC will do the trick, though a higher current will give increased reaction rate.
Ironically I've used this process to go the other way quite often with soda cans. Australia is undoubtedly the world leader in aluminum/bauxite production, though here in the US especially in the last year, alumina and oxide products have gone through the roof in price. Soda can aluminum isn't all that great for structural metal and smelting it is less cost effective than just running it down to a recycler even with fuel costs, but works just fine for making oxide particles for refractory materials.
Great video!
I've seen papers claiming aluminium can be plated from 'water in salt' conditions. Also room temperature ionic liquids can be used.
Recently an aluminium sulphur battery has been proposed using molten inorganic salts, which runs at about 100C. If that's possible it seems like a lower temperature manufacturing method for aluminium would be possible.
That's super cool! I've been hearing a lot about ionic liquids lately and they definitely seem to be gaining some significant development in many areas.
Sadly, the difficult synthesis and safety issues involved with aluminium chlorides and ionic liquids make these kinds of experiments very tricky on a 'home chemistry' scale. Very interesting to read up on though, and might lead to a less energy intensive aluminium production method as you say.
Are there other oxidation states for aluminum which might have limited the aluminum metal product in a short run batch?
Not that I'm aware of...
I've honestly got no real clue about what caused the low yield in the second run. It might be a result of the metal not coalescing properly in the small quantities I made (leaving it as a microscopic dust in the flux), maybe the cryolite mixture was too dense and the aluminium was actually floating and reacting with air, maybe I just couldn't find the globules of aluminium at the end, or as you've said, maybe there's some side reaction I'm not considering under these conditions.
Maybe I'll try again some day, but I've already spent far too much time on this project for now.
Hey, general question, how long do you find those graphite crucibles last?
I'm not really sure honestly. Using one of these for a Hall-Heroult cell four or five times ate away at the crucible quite significantly (maybe a third of the way through the walls of the graphite), and then I accidentally broke the crucible not long afterwards.
Now that I've got a couple more of them, and have used them for other processes, they seem to be lasting really well. I haven't noticed much disintegration over the five or so times I've used them for various things. Depending on what you use them for, they'll almost definitely survive for more than 20 hours of total use (probably much more than that).
Could this work with the mineral corundum (ignoring the transition metal impurities like titanium and chromium) which as you probably already know consists of crystalline aluminium oxide?
The crystalline form of corundum may prevent it from effectively dissolving in the cryolite melt, I'm not sure.
If it dissolves, it should work, provided those impurities don't interfere with the reduction process (which they probably are quite likely to do).
cool
I wonder if the lid being open while running caused any problems?
It's possible I suppose.
I assumed that it would be fine since they have the cells open to air in industrial setups, but maybe leaving it open to oxygen led to some problems.
Nice video!. Any idea why, i made some aluminum oxide like you did but when I calcined it, it all ended up black
I ran into this problem a couple of times as well. The black colour is likely due to the fact that some bits of plastic from the labels are dissolved by the acid when you dissolve the aluminium cans. I think the process of decomposing the aluminium hydroxide at high temperature also decomposes these leftover organic components into carbon dust, which gives the oxide a black colour.
I've found that you can avoid the problem if you wash the aluminium hydroxide with copious amounts (like, a LOT) of water.
@Scrap Science The strange thing is, I used aluminum foil. And first the hydroxide was completely white then when i heated it up it got completely black. I think that the foil should be petty pure aluminum and not contain anything other.
Generally, aluminium foil contains a LOT of plastic. They add it to prevent the aluminium from tearing easily. In fact, foil probably contains more plastic (by weight) than a standard aluminium can with its label.
The plastic from the foil is probably the source of your black colouring. Your aluminium hydroxide was perfectly white because the organic contaminants didn't decompose to carbon until you heated it.
@@ScrapScience Thanks, and ok i will have to try it
More science please 🙏 🙂
is it possible that "molten" isn't enough? heating it more could affect the relative densities of the aluminum vs the cryolite, or the solubility of the aluminum, aluminum oxide, oxygen, or all of the above components in the melt. maybe the temp needs to be higher to get the %dissolved aluminum oxide, with most of it just sitting at the bottom. I'd have to check a phase diagram to see if it might have separate alumina rich solidus or something.
It's definitely possible. According to everything I found online, it seemed like industrial processes attempt to use the lowest temperature they can, so I assumed that was the way to go. I found a couple of sources stating that the solubility of aluminium oxide is above 20% by weight, and the solubility of aluminium itself was less than 0.1% by weight in cryolite at its melting point. I could definitely be wrong there however, and it wouldn't surprise me if the temperature I used wasn't ideal.
When you pour the melt isn´t the aluminium reacting with oxigen ? wouldn't worth it to let the molten cold in the crucible so that the aluminium would be protected from oxigen?
Oxygen doesn't appreciably react with aluminium on the timescale of pouring it out of the cell, the most oxidation you'd expect is a small oxide coating on the droplets, which will be present no matter how you extract the metal.
Letting the mass cool in the crucible would make it impossible to remove, so pouring it out is essential in this case anyway.
Could your metal be dissolved in the salt? I’ve noticed that when making sodium in a castner cell, metal production seems to peak after the salt is saturated. Also, you need a modified microwave oven transformer to provide at least 50 amps to the melt. Even at 50 amps, production is still super slow. I feel like my cell needs at least 100 amps to produce well.
It's definitely possible that some of the metal dissolved in the mix. Looking up some literature online, it looks like the solubility of aluminium in this kind of mixture is only around 0.1% by weight at 1000 C though. If this is true, it should have only subtracted about 0.1 g from the yield, but maybe there are some other factors surrounding the solubility that I'm not considering, I don't know.
A castner cell sounds like fun as well! I'm currently working towards putting together a very simple cell myself. I suppose I'll have to look into modifying a MOT at some point too.
@@ScrapScience In my personal experience, your result is reasonable given the run time and power, despite the calculations. The scale is so small and the run time so little that it may amount to a “rounding error” that exaggerates the result. The castner cell only requires one electron per Na yet Al requires 3 electrons. Considerably more difficult. Throw 50-100 amps at it and run for 8-12 hours. I bet you’ll see results. Hope this encourages you. Great job doing something very rare and hard to find on the internet!
@@ScrapScience In my personal experience, your result is reasonable given the run time and power, despite the calculations. The scale is so small and the run time so little that it may amount to a “rounding error” that exaggerates the result. The castner cell only requires one electron per Na yet Al requires 3 electrons. Considerably more difficult. Throw 50-100 amps at it and run for 8-12 hours. I bet you’ll see results. Hope this encourages you. Great job doing something very rare and hard to find on the internet!
with this furnace can we molt Cu°(s) and Au°?
Yep, we could. But simple metal melting and casting isn't going to be the focus of this channel any time soon I'm afraid.
Lucky me I found this video.am trying a project of extracting aluminum from kaolin but the biggest headache was this cell .
Could you try something like this with iron, instead? You could then use a powerful magnet to help you extract it at the end.
The molten electrolytic procedures which can be used to generate iron (at least, the ones I'm interested in attempting) generally use molten salts which are themselves soluble in water, so separation of the salt bath from the metal product is significantly easier anyway. I'll definitely be giving it a go in the (possibly very distant) future.
is it possible to perform a sodium production searched a long time for a video i cant found one
I made a video on sodium production three weeks ago. You can find it on my channel page.
I think you might have had slightly better results if you heated the the mixture a bit over melting-temperature, and then poured into a pre-heated upside-down cone.
That way the aluminum would have a chance to sink to the bottom before everything solidified.
Another less optimal solution might be to just let it cool without pouring, before crushing the crucible.
Nice video....is it true that in the industrial process the current is of 100 ampere?and also why did you not use fluorspar?
Actually, most industrial cells use over 100,000 amps, hence the incredibly high power consumption.
Fluorspar is is an additive which can only lower the melting point of the mixture by ~50 C, so I didn't really think it was worth the effort.
@@ScrapScience oh...interesting..(this is my second accnt btw)
@@ScrapScience so why is fluorspar used in the industrial process?
In an industrial setting, lowering the melting point from 1000 C to 950 C is a valuable thing to do, since it lowers the energy required to melt the mixture. It's more cost effective for large-scale procedures.
@@ScrapScience 👍🏼thanks for answering..
19:10 is that sodium metal burning when you poured ?
I'm afraid not, there's no sodium produced in this reaction (in fact, 1000C is above sodium's boiling point). The burning bits are most likely super hot pieces of carbon from the crucible reacting with the air.
It'd still be cool to see some actual figures on the true feasibility of this rather than the usual chuckle and dismissal. Of course it's never going to be a good option while industrial producers exist, but society bucks and buckles all the time. A smart chemist never knows when they may need some pure elemental aluminum, and it's just not worth hiking passed Blood Lake and over Mt. Skull to ask the fuel barbarians if they could spare a killergram - not kilogram, because it's their world now, so we use their words.
I mean, if you just want the figures of how feasible it is, it's relatively simple.
First, pretty much everything in the reaction is catalytic except for the electricity, the aluminium oxide, and the carbon anodes. The rate at which these things are consumed, per kilogram of aluminium produced, is:
1) 1.89 kg of Al2O3 is required for every kg of aluminium produced.
2) 15 kWh of electricity (when running at 5 V) are required to make a kilogram of aluminium at 100% yield. The process seems to work better on larger scales, but under the yield that I was able to get, you'd require 650 kWh per kilogram of product.
3) Under the best case scenario, you'll probably use 500 g of carbon per kilogram of aluminium.
Overall, I can personally make aluminium at a price of about $183/kg ($8 for the aluminium oxide used, $160 for the total electricity, $15 for the carbon electrodes). This is about 100x more expensive than standard aluminium prices. Of course, this will depend on electricity prices and how good your yield can be, but even with cheaper electricity and a much better yield, it's difficult to get anywhere close to a good price for the aluminium you make.
Why didn't you pour out all of the cell contents on either of the 2 runs, especially considering that the aluminium is supposed to be at the bottom of the cell?
Could the missing aluminium maybe be in there, covered by the last of the flux that was still left in the crucible?
I didn't put it in the video, but I actually did pour out the whole contents of the cell in every run. It took multiple pours to do this each time, so I thought it would be boring to watch for the viewer.
Rest assured that I was actually looking through the whole cell mixture when I was looking for the aluminium, and also did a thorough check of the bottom of the crucible after every run.
@@ScrapScience Oh, right, that makes a lot more sense actually!
I'm still shocked at how low the yield was the second time. Yes there could be numerous reasons why the molten Al might not have been able to come together into a single bead, but for the slag to look that bare and devoid of small metallic spheres, together with the small size of thost largest metallic pieces that you were able to collect, is just really weird.
That being said, it was still a very solid demonstration of the process, that I am very thankful to have been able to see.
PS. I also just realized how condescending that assumption sounds; I do sincerely apologize for that. *Obviously* you wouldn't have missed something so obvious!
Haha, don't worry, I wouldn't call that condescending at all. It's definitely the kind of mistake I'd make, and these types of questions do actually help in letting me know which things I should make more clear in my videos.
And yeah, the low yield was a little confusing, given the fact that there shouldn't be too many side reactions under these conditions. As a matter of fact, I actually tried this reaction a total of four times in my attempts to get it to work (the video only shows my first and fourth attempts). From all these reactions I've performed, it seems like the only thing which gave good results was to keep the total volume of the reaction as low as possible. I assume this just makes it easier for any microscopic aluminium to coalesce. Maybe doing this on an even smaller volume would actually give something close to the expected yield, but after more than a month of trying this reaction, I was just happy to get some product, and really couldn't bring myself to do it a fifth time. Maybe I'll try this again at some point in the future.
I'm sure if you expressed your interest to Comalco, they might consider giving you a tour...or a job. 😉
Haha, that'd be nice. Maybe I'll look into it at some point :)
Hi, great video. If you want more Aluminium so you need 7Volts and 40 Kiloampere. It's like you said this is not for Hobby.
Can you do a video on nickel recovery from either stainless steel or some sort of chemical?
And don't forget purifying the Chrome and vanadium , not just the nickel...
Make a video on making aluminium powder
Maybe one day, if I need lots of it. Seems a little simple though...
@@ScrapScience hmmm
@@ScrapScience Ball milling it gets a little dicey once you get down to a certain size. You need to coat it with carbon, stearic acid, or something similar. Otherwise it becomes pyrophoric and will burst into flames when you open the mill. Apparently you can just open it occasionally so there's an oxide layer created as you go.
Hmm, maybe you could explore the chloride process in the future.
I'd definitely like to one day. However, the production of aluminium chloride from the oxide is no easy task, and reducing the chloride with an alkali metal is also pretty tricky, so it'll probably be a long while before I give it a go, if I ever decide to try it.
I do apologise for your second comment disappearing here, any comments containing a hyperlink are automatically deleted as spam control, and I haven't figured out a way to stop it from happening.
Regardless, I did see your comment (and the link) breifly.
Sorry for the misunderstanding here, I hadn't actually heard of this electrolytic 'chloride process' before. It looks super cool! (and it's always nice to find out about another electrolytic procedure).
I'll definitely try to figure out a way to do it if possible. Getting enough AlCl3 and working with it at high temperature will be the tricky part though, maybe an extremely small-scale demonstration might be best...
@@ScrapScience yh just be careful with AlCl3 around water/moisture, it readily hydrolyses and releases gases HCl
I wonder why Cody unlisted his aluminum making from dirt, I remember watching it when it came out. Strange how some videos just go missing.
I was initially pretty confused too (it was one of my favourite videos of his).
Based on one of his recent twitter updates - twitter.com/CodysLab/status/1443439394724012034 - it seems like he's working on making another video about making aluminium by the metallothermic reduction of AlCl3, so maybe he's taken it down because he's working on a more updated video? I don't know, maybe we'll find out.
@@ScrapScience The site is incredibly slow from what I remember, but somebody has personally hosted an archive of the bigger youtubers unlisted/taken down videos, I'm going to have to find it again because I forgot to bookmark it like an idiot, Will link it when I find it again.
@@mikahandony1562 Did you find it? I've been watching Cody since the early days and I had completely forgotten he did that, would be lovely to see it again.
Thanks for the great video-- NASA is working on how we can get aluminum (and other minerals) from lunar regolith. It may not be as easy as it looks on paper...
That sounds super cool! I'll have to look into it.
Definitely seems like a tricky problem if you don't have easy access to bauxite.
I think easier to go around and pick it up. :)
get ya jab
sounds really brainy!! get the scientist effect. :)
Electrolysis is about the electrochemical potential and then large current. That means your voltage was wrong all along.
How does this mean the voltage was wrong?
pour into a column, not a pan, density diference.
Are you making fluorine gas at home
Nope. I sure hope not at least.
@@ScrapScience fluorine is not gonna be a lot anyway but that method can be used to make fluorine at anodes
89% of electricity is hydro powered? where are these dams in Tasmania?
All over the place. We have about 30 of them I think, with the total capacity to generate a maximum of 2.3 GW all up.
So you're making aluminum metal from its oxide? You should rather make it from woodash, then we learn something!
Annnnnnnnnnnd you therein reverted most of it back into aluminum oxide... ~( ,m,)~
You don’t get AlOH from Al and HCL…..you must have ment NAOH !
You also don't get Al(OH)3 from aluminium and sodium hydroxide either (that gives you sodium aluminate). As I said in the video, what I did was dissolve the aluminium in hydrochloric acid, and then precipitate it from solution as the hydroxide.
u in ias where ann organs eye nation
my pension that is
recovery process is at fault for sure
why not try to make sodium metal with this kinda setup instead? ive seen some success with even alkali nitrate salts, molten electrolysis is generally just awful
In fact, I made a video on electrolytic sodium metal production three weeks ago, you can find it on my channel page.
Searching for that one elusive process took me all of 20 seconds: th-cam.com/video/bI6OuGBx4nY/w-d-xo.html
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