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ManyInterests
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[*] posted on 20-5-2021 at 12:34
cleaning heating mantle after spill?


I was boiling off some Methanol to purify some acetylsalicylic acid. The jar I used was quite poor for that task and cracked and I had methanol fumes all over the place. I didn't see it as it happened, but I did remove the jar from the mantle and keep it on for a minute, it still fumed before I killed the power. the piece of cardboard I was putting it on was also soaked.

There is no visible damage to the mantle (which I am glad) but it still fumes if I turn it on. Any damage control to this? Or do I just let all the methanol evaporate before doing anything in the future (this time with no chances taken on the glassware! I won't use jars. Just the borosilicate stuff from now on).
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[*] posted on 20-5-2021 at 12:49


Take it outside, dismantle and let it evaporate. Then mantle and turn on the heating for a while. Pure methanol shouldn't do any damage.
Do not do it without proper ventilation as breathing methanol vapour can have severe consequences.
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[*] posted on 20-5-2021 at 13:05


Just let it evaporate for a long while and it will be fine. I'm sure that I have spilt far worse on them, and they keep going...
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[*] posted on 20-5-2021 at 13:08


OK that's good. I decided to wipe it and everything with soap and water. Most of the residue was ASA.

I did smell some of the Methanol, but thankfully I got out before I felt anything. If there is any benefit to having an anxiety is disorder is that it makes you run away from any remotely dangerous situation.

Quote:
Take it outside, dismantle and let it evaporate. Then mantle and turn on the heating for a while. Pure methanol shouldn't do any damage.
Do not do it without proper ventilation as breathing methanol vapour can have severe consequences.


Good for me is that I do all evaporation and mantle heating work outside. No exceptions.

When you say dismantle, you mean disassemble? I don't think it's possible for me to do that. Or do you mean remove all glassware off the mantle itself?
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[*] posted on 20-5-2021 at 13:20


Also I am going to note this for here. I only used Methanol because I was not aware I could also have used Ethanol for this extraction/purification. I found a pharmacy near me that sells rubbing alcohol with a 95% ethanol content. From now on I will use that. Much safer.
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[*] posted on 20-5-2021 at 14:33


Quote: Originally posted by ManyInterests  

When you say dismantle, you mean disassemble?


Yes, but it might be an overkill. Mine are easy to disassemble as there is a need to remove just 4 screws and already did that once or twice after unexpected fountains. Letting it to evaporate without disassembling will also do a trick
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[*] posted on 20-5-2021 at 15:21


Quote: Originally posted by Oxy  
Quote: Originally posted by ManyInterests  

When you say dismantle, you mean disassemble?


Yes, but it might be an overkill. Mine are easy to disassemble as there is a need to remove just 4 screws and already did that once or twice after unexpected fountains. Letting it to evaporate without disassembling will also do a trick


Yeah I'm not going to do that. The spill wasn't that bad, and right now the smell and fuming is completely gone. I put my 1 liter boiling flask and am boiling some water to make sure it's all clear. After boiling some and letting my flask cool a little I did see some stains on the outside of my flask, which could be residue from the spill. I don't think this will negatively affect future projects.

I do plan on making nitric (fuming and 65-68%) and sulfuric acid with this. I've learned a very valuable lesson on the proper use of correct glassware for the job. I hope this knowledge will prevent the spill of a more dangerous and corrosive chemical.
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[*] posted on 20-5-2021 at 20:19


Thankfully it was a relatively small incident, it will be much worse if you would spill hot mixture of sulphuric/nitric acid.
A proper glassware is must-have, especially when living in the times, when it's quite cheap and readily available :)
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[*] posted on 31-5-2021 at 15:41


Quote: Originally posted by Oxy  
Thankfully it was a relatively small incident, it will be much worse if you would spill hot mixture of sulphuric/nitric acid.
A proper glassware is must-have, especially when living in the times, when it's quite cheap and readily available :)


Yeah. I'm glad I made sure I got the glass... because I finally decided to purify and concentrate some sulfuric acid.

My setup worked brilliantly! I used around 275/280ml of drain opener, around 17.5 ml of 32% H2O2 (I concentrated it from the 3% pharmacy stuff by very slowly evaporating the water. I got 40 to 60ml of the stuff from 1.1 liters of 3%. Not the most efficient method, but it works and it produces the quantities I need in the concentration I need) and I cleaned the drain opener so thoroughly it was crystal clear.

Since I am lacking a condenser (it's coming though!) I decided to boil it. Turns out the setup I made for this was absolutely perfect for not only protecting me from any fumes, but my neighbors as well, so I'm proud of that. The setup was so rocksteady that it didn't budge when the sudden bursts of fumes popped up.

And those moments were a sight to behold! I had no idea that much fuming would come out. I am not sure if I overboiled it, but the end result is I now have 250ml of very pure, very clean H2SO4. I'm really proud of this! :D From all the stuff I have been looking into purifying the stuff, it seemed like it would be the most dangerous thing I would ever attempt, and I succeeded without a hitch!

Boiling water also helped as a good exercise because if there is something I learned about borosilicate glass is it doesn't cool down as quickly as normal glass. So after doing my acid boil, I knew I needed to let it cool for many hours before even thinking about touching it.

[Edited on 31-5-2021 by ManyInterests]
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[*] posted on 10-7-2021 at 15:19



Do you have information on the recrystallization of ASA in ethanol?
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[*] posted on 28-9-2021 at 02:26


Quote: Originally posted by VeritasC&E  

Do you have information on the recrystallization of ASA in ethanol?


Hi! Sorry for the long wait time.

Unfortunately I don't have much experience with that... yet. What I am going to do, however, is try to purify more ASA using 95% ethanol instead of methanol like I did previously. Also I will be using proper lab glass instead of a canning jar to protect against heat shock.

All information I found online was based on using regular strength (325mg) aspirin tablets. I got 300 extra-strong tablets carrying 500mg each. I got quite a lot of 95% ethanol from my local pharmacy, so I won't skimp on its use.

After I crystalize them, I will try to recrystallize and see what happens. I rarely do recrystalizations, but in this case I think I will. My previous batch had a reddish tint due to the red dye used on the Bayer extra-strong tablets (the regular strength has no such dye). I am using store-brand tablets this time, which have no dyes.

I'll also need to replace my scale since my current one is broken to make proper measurements.

I will report what I find once I am done. Hopefully by the end of this week.
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[*] posted on 2-10-2021 at 21:34


So I've taken around 120 grams of crushed extra-strong (500mg) aspirin tablets and performed the same process as before, except with 95% ethanol and not methanol. I used an excess of ethanol to make sure all the ASA was dissolved into solution. I ended up with a product of around 50 to 55 grams of pure ASA. The problem is that there is a bit of a smell to them that is a bit like the ethanol despite leaving it out to dry for days. Maybe it needs a little bit longer or maybe I might need to put it in my oven at a low temp to make sure all the alcohol is gone, but I am not entirely sure.

Either way, compared to my previous run, it is pure white without any clumping at all. I powdered it extremely fine. I don't think it needs any recrystallization as not all the alcohol appears to be gone. Also my yield was surprisingly small. I was expecting far more than just 50 to 55 grams from the 120 grams I started with.
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[*] posted on 2-10-2021 at 23:33


If you have a low yield to you either used to little ethanol or too much; either not all ASA dissolved out of the pills, or there is still ASA in the ethanol that did not crystallize. You could boil down the ethanol to check if there is a second crop crystallizing out. Didn't you use 150g ASA instead of 120? You don't mention the amount of ethanol, but I guess the extraction was not complete.

When the extraction was incomplete it is because the solubility of ASA in ethanol is not high enough to get all out in one go. You could reuse the same alcohol a couple of times to get it all out.

I did this extraction once with acetone, I remember the product to be clean as well, there just isn't anything else in the pills that dissolved in the solvent.

The smell is probably methyl ethylketone that was used to denature the alcohol. You can get rid of it by refluxing the alcohol with NaOH and distilling it afterwards. To get rid of this smell from your ASA you can just wait a little longer, it will evaporate eventually.

Edit: I thought you used 300x 500mg pills, but you say you used 120 grams of the pills. How many pills is that? The weight of the pills doesn't say too much about the yield you got.

How do you know you used an excess of ethanol? Do you have solubility data?

[Edited on 3-10-2021 by Tsjerk]

[Edited on 3-10-2021 by Tsjerk]
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[*] posted on 11-10-2021 at 21:01


I did use 300 x 500mg pills and in grams it did come out to 120 grams. I could be wrong as my scale was acting up at the time (I really need to get it replaced). The excess was based on my previous extraction with methanol instead of ethanol. basically I calculated 200 ml of methanol/ethanol per 100 pills. I added 750ml of ethanol to make sure I had enough for everything. After I dissolved the crushed pieces, I added another 100 ml of ethanol to wash the remaining residue before filtering whatever solids were left.

I was principally following NileRed's video on the subject: https://youtu.be/LvYetXXnTmI

The smell wasn't there when I used methanol previously, but there was no physical particles left in the solution. I looked over the wiki and it did say 20 grams was soluble in 100 ml of ethanol. Maybe I didn't use enough and should have done my extraction in batches instead of all at once.

I put the solution on my heating mantel and heated it as a low 65 degrees Celsius until there was little liquid left, then I left them to air dry for a while. I used paper towels to press out some of the remaining liquid before leaving them out for a few days. The smell still remained even after I took it out again and left the container open for another 24 hours.
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[*] posted on 12-10-2021 at 11:00


Methanol doesn't contain MEK, as it doesn't need to be denatured.

You probably used enough solvent, but 300 x 500mg weighing 120 grams doesn't really sound right, does it? So your 50 gram yield probably is off as well.
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[*] posted on 12-10-2021 at 17:11


Yeah it is weird. I really don't know why since my previous yield was substantially higher. I have a feeling that my scale may be far more off than previously anticipated. I'll need to halt any experiments until I get a new scale.

And also I will dry to oven dry my ASA to see if the smell goes away. I plan on making picric acid with the ASA. I fear that any MEK will end up contaminating my end product and I don't want to nitrate any MEK.
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[*] posted on 13-10-2021 at 10:52


Some good news. Oven drying my ASA for around 10 hours at around 70 degrees Celsius. completely dried it off and got rid of the smell.

I have some MEK at home and took a whiff of it to see if the smells were identical. I kinda wish I hadn't! Gave me a mild headache. The smell was similar, but the one on my ASA was far fainter so it might have been something else.

Either way it's gone and that's all what matters.
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[*] posted on 14-10-2021 at 18:23


I may be the first one in this thread to mention that both these are flammable, and can sometimes deflagrate fast enough to spray the liquid everywhere.

Switches arc as they turn off. In the future would it be worth it to have an extension cord or something else you can shut off remotely after a spill?

The whole thing reminds me of a pg-13 version of this thread. In that case a heated flask of methanol (mixed with a much more hazardous material) broke, and the other ingredient caused a major injury.

There's the (probably worthless) thoughts that came to me reading this.



[Edited on 15-10-2021 by Vomaturge]




I now have a YouTube channel. So far just electronics and basic High Voltage experimentation, but I'll hopefully have some chemistry videos soon.
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[*] posted on 14-10-2021 at 19:43


That's exactly my setup. Basically I have a power bar and into that I put in a extension cord which I plug the mantle plug into. This allows me to keep my mantle on my balcony to do dangerous work (such as boiling sulfuric acid) with complete safety and should anything go wrong, the switch I need to push is 2 meters away (and behind the safety of a closed window and a wall.

I never got even the slightest whiff of sulfuric acid when I was boiling them. During nitration with the purified sulfuric acid... my god was the smell unbelievable, especially compared to the impure drain opener. This is why I am getting a respirator with a acid filter cartridge.
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