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Author: Subject: The short questions thread (3)
hyfalcon
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[*] posted on 8-6-2013 at 10:18
Ball milling question


I just got 5lbs. of Mg turnings in and I want to ball mill them with alumina media. Is there any worries about doing this? I've done tons of black powder and single chemicals but I've never run Al or Mg before. TIA
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elementcollector1
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[*] posted on 8-6-2013 at 10:22


Al foil takes forever with steel media, and given Mg's hardness compared to Al, I'd say you're going to have a rough time of it. Put lots of media in, and wait a few weeks, opening the tumbler every week or so (if it starts to swell and it's made of rubber, that's a bad sign).
I do seem to remember someone getting badly injured after trying to mill Mg, however - I believe it was sticky'd on the Energetic Materials board.




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ElectroWin
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[*] posted on 8-6-2013 at 10:55


i wonder if it could ignite the magnesium?

3 Mg + Al2O3 --> 3 MgO + 2 Al

i think you dont want to do that
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hyfalcon
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[*] posted on 8-6-2013 at 11:00


I need to be more clear. I just got 5lbs. of Mg turnings in that I need to reduce to a smaller micron size. I'm not mixing Mg and Al and trying to ball mill it together.
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elementcollector1
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[*] posted on 8-6-2013 at 11:07


I know, it was a comparison from my own experience with just Al.
Do you think a coffee grinder stands any chance, or is this stuff too large to be effectively 'grinded'?




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hyfalcon
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[*] posted on 8-6-2013 at 11:13


It's pretty brittle and thin shavings. Looks like it should break up pretty easily if it won't go up in flames on me that is. Picture long thing brittle turnings with a faint oil odor to them.

[Edited on 8-6-2013 by hyfalcon]

---------

Skylighter had them on sale the other day for $5.99/lb so I bought 5lbs. to have some to mess with.

---------

This is what I want to avoid.

http://www.bobforward.com/magmill.htm

------

Maybe I WON'T be doing this!
http://www.sciencemadness.org/talk/viewthread.php?tid=14884

[Edited on 8-6-2013 by hyfalcon]

[Edited on 8-6-2013 by hyfalcon]

[Edited on 8-6-2013 by hyfalcon]

[Edited on 9-6-2013 by hyfalcon]
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amazingchemistry
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[*] posted on 8-6-2013 at 18:32


Is it ever okay (as in, effective) to use a gas trap instead of a fume hood?
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[*] posted on 9-6-2013 at 09:29


Quote: Originally posted by amazingchemistry  
Is it ever okay (as in, effective) to use a gas trap instead of a fume hood?


Come on now, you know it very well depends on what the gas is and how much gas will be evolved. Of course the safest method is to use a fume hood but sometimes economically it is not the best because they can be pricey to build or buy. You have to use your own judgement, can you hold your breathe and run to safety should something bad happen? Is it worth it to take these risks? etc..




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BobD1001
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[*] posted on 9-6-2013 at 10:18


Quote: Originally posted by hyfalcon  
I just got 5lbs. of Mg turnings in and I want to ball mill them with alumina media. Is there any worries about doing this? I've done tons of black powder and single chemicals but I've never run Al or Mg before. TIA


The aluminum oxide media should help reduce the particle size of the Mg quite efficiently. It still may take a week or so to get 'airfloat' mg powder. Keep in mind, that as the mg particle size is reduced, the surface area increases dramatically, and will quickly use all available oxygen within your ball mill jar to form an oxide layer, however once this oxygen is depleted, the mg will have a bare surface, and will readily react with air. This is called Pyrophoricity, and it will essentially spontaneously combust upon opening the milling jar. To prevent this, you must open the jar and expose the powder to fresh air (to build an oxide layer) a few times a day at minimum. Also, you can add 2 parts by weight of boric acid the the mill to act as a protective coating from pyrophoric tendencies.
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hyfalcon
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[*] posted on 9-6-2013 at 14:22


Quote: Originally posted by BobD1001  
Quote: Originally posted by hyfalcon  
I just got 5lbs. of Mg turnings in and I want to ball mill them with alumina media. Is there any worries about doing this? I've done tons of black powder and single chemicals but I've never run Al or Mg before. TIA


Also, you can add 2 parts by weight of boric acid the the mill to act as a protective coating from pyrophoric tendencies.


When you say 2 parts, might you have meant 2%?
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elementcollector1
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[*] posted on 9-6-2013 at 21:03


http://www.youtube.com/watch?v=UkPLu6mgdWA
Is 30 mmHg (as he claims) good enough for most applications?
(Also, do you believe him on that claim?)

EDIT: That gauge goes from 0 mmHg to 30 mmHg - does that actually mean 730 mmHg (or 30 below atmospheric pressure)?

[Edited on 10-6-2013 by elementcollector1]




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[*] posted on 10-6-2013 at 17:59


Does anyone know if Aluminum is resistant to Hydrazine Hydrate?

I have a tiny 250ml retort that's not doing a good job at condensing the vapor. The condensing arm is too short. I recently bought a TIG welder and with that I could make a distillation setup from Aluminum.
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[*] posted on 13-6-2013 at 14:28
inHg


Quote: Originally posted by elementcollector1  
http://www.youtube.com/watch?v=UkPLu6mgdWA
Is 30 mmHg (as he claims) good enough for most applications?
(Also, do you believe him on that claim?)

EDIT: That gauge goes from 0 mmHg to 30 mmHg - does that actually mean 730 mmHg (or 30 below atmospheric pressure)?

[Edited on 10-6-2013 by elementcollector1]


That gauge is in inches Hg. A high vacuum is about 29.5 inches of mercury or 760 mm of mercury.




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[*] posted on 13-6-2013 at 15:46


Quote: Originally posted by elementcollector1  

EDIT: That gauge goes from 0 mmHg to 30 mmHg
No, look closely. It's calibrated in "in Hg", or inches of mercury. This is a gauge reading, not an absolute one, which means that it's that much pressure less than ambient pressure (which varies with the weather).
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elementcollector1
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[*] posted on 13-6-2013 at 16:21


Quote: Originally posted by watson.fawkes  
Quote: Originally posted by elementcollector1  

EDIT: That gauge goes from 0 mmHg to 30 mmHg
No, look closely. It's calibrated in "in Hg", or inches of mercury. This is a gauge reading, not an absolute one, which means that it's that much pressure less than ambient pressure (which varies with the weather).


According to this and the above post, if it went down to around 25-30 it would be a good quality vacuum, correct?




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[*] posted on 13-6-2013 at 18:50


Quote: Originally posted by elementcollector1  
According to this and the above post, if it went down to around 25-30 it would be a good quality vacuum, correct?
"Good quality" is entirely dependent upon what you want to use it for. And that answer may not be a short one.
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[*] posted on 13-6-2013 at 19:43


Well, to list them all out, vacuum filtration, possibly vacuum distillation, and (someday in the far-off future) cesium distillation. (I'm guessing it won't be all that good for the last one.)



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[*] posted on 14-6-2013 at 06:48


Quote: Originally posted by elementcollector1  
vacuum filtration, possibly vacuum distillation
Vacuum filtration: sure. Vacuum distillation: maybe.
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[*] posted on 24-6-2013 at 20:09
Sodium Citrate


I would like to make some Benedict's Reagent for detecting sugars in a solution.

Can I produce Sodium Citrate as the salt of Sodium Hydroxide and Citric Acid?
i.e. 6NaOH + 2C6H8O7 -> 2Na3C6H5O7 + 6H2O

Corollary, given a lack of precision measurement and unknown water content of the NaOH; I should titrate the NaOH into the citric acid to minimize unreacted reagents, no?

Thanks
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[*] posted on 24-6-2013 at 22:45


For 24/40, it seems that pear shaped flasks aren't the go to, at least as far as I have seen.It's almost always the Round bottom type. But in the Smaller joints, like 14/20 and in a large number of Quickfit glass sets It seems that they are far more commonly used if not the default flask shape. Pardon this but :For smaller scale work what makes that pear or pointed bottom shape so appealing?



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[*] posted on 25-6-2013 at 07:32


Quote: Originally posted by ElizabethGreene  
I would like to make some Benedict's Reagent for detecting sugars in a solution.

Can I produce Sodium Citrate as the salt of Sodium Hydroxide and Citric Acid?
i.e. 6NaOH + 2C6H8O7 -> 2Na3C6H5O7 + 6H2O

Corollary, given a lack of precision measurement and unknown water content of the NaOH; I should titrate the NaOH into the citric acid to minimize unreacted reagents, no?

Thanks


That's correct, but the ratio should be 3 : 1 : 1: 3. Always use the simplest ratio in your equations.




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[*] posted on 26-6-2013 at 10:37


Is there an ion exchange between CaH2 and LiClO4 ?



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[*] posted on 26-6-2013 at 10:42


Quote: Originally posted by DubaiAmateurRocketry  
Is there an ion exchange between CaH2 and LiClO4 ?

Under what conditions? Not in aqueous solution- the calcium hydride will react with the water. Not if you melt them together (BOOM!).




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[*] posted on 26-6-2013 at 10:43


Quote: Originally posted by DraconicAcid  
Quote: Originally posted by DubaiAmateurRocketry  
Is there an ion exchange between CaH2 and LiClO4 ?

Under what conditions? Not in aqueous solution- the calcium hydride will react with the water. Not if you melt them together (BOOM!).


yes i know, tell me a solvent then. it also react with alcohols.

I have some NH2 terminated liquids, does those work ? or glycols ?

also, ive got acetone.




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[*] posted on 26-6-2013 at 11:26


Quote: Originally posted by DubaiAmateurRocketry  
Quote: Originally posted by DraconicAcid  
Quote: Originally posted by DubaiAmateurRocketry  
Is there an ion exchange between CaH2 and LiClO4 ?

Under what conditions? Not in aqueous solution- the calcium hydride will react with the water. Not if you melt them together (BOOM!).


yes i know, tell me a solvent then. it also react with alcohols.

I have some NH2 terminated liquids, does those work ? or glycols ?

also, ive got acetone.


The hydride is a very strong base and a pretty good nucleophile. It will react with alcohols, possibly also primary and secondary amine, and probably also ketones. I can see it either reducing acetone to calcium isopropoxide, or deprotonating it and starting a Claisen condensation (and that's assuming the acetone is dry, and not 5% water like most of it). If you're trying to make calcium perchlorate, there must be an easier way.




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