The Vespiary

The Hive => Newbee Forum => Topic started by: fnord on June 10, 2004, 04:18:00 PM

Title: isolating phosphoric acid
Post by: fnord on June 10, 2004, 04:18:00 PM
just found a rust remover in my local marine store that says it contains phosphoric acid and was wondering how to isolate just the phosphoric acid, would fractinal distalation work? what othe methods might be usefull i know the phosphoric acid frezes at below 20 but the rest of the mixture freezes too any ideas?

Title: phosphoric acid is useless
Post by: barkingburro on June 10, 2004, 05:12:00 PM
can't do much of anything with it. you are prolly thinking of phosphoNic. if you want phosphoric you can get it by the gallon at most hardware stores as a surface cleaner.
Title: Corrosive acids are not nice at 280°C...
Post by: Rhodium on June 10, 2004, 06:08:00 PM
would fractinal distalation work?

Look up the boiling point of phosphoric acid and see if you might want to rethink that strategy.

Title: phosphoric is at building supply companies.
Post by: ApprenticeCook on June 10, 2004, 09:58:00 PM
phosphoric is at building supply companies.

H3PO4 - d213oC
so in other words if you bring it to that temp you will decompose the acid, hence screw it. Thats before it boils too.

Title: Boil water off
Post by: Nicodem on June 11, 2004, 03:33:00 AM
You can simply concentrate the rust remover by boiling off water. Measure the density to get the concentration.
But where I live it does not contain much H3PO4 (about 10%) so its not really a good source.

Title: thats assuming it only contains phosphoric...
Post by: ApprenticeCook on June 11, 2004, 09:21:00 AM
thats assuming it only contains phosphoric acid and water though.

Title: H3PO4 with water and MeOH
Post by: Nicodem on June 11, 2004, 11:35:00 AM
Well, mine also contained some methanol but that is nothing bad. I did fuck up once though, when I used ceramic boiling chips that dissolved almost completely and made the H3PO4 dirty and useless. It's incredible but hot H3PO4 can dissolve the silicates!

BTW, H3PO4 is also good for making polyphosphoric acid.

Title: anything below pH3
Post by: r2e3 on June 12, 2004, 06:37:00 AM
well - thats for silica gel
Title: ok but i still fail to see the usage
Post by: barkingburro on June 12, 2004, 09:14:00 AM
of this endeavor. if purely for shits and giggles, cool. but if your purpose is to obtain phosphoric, why this method? it is STRAIGHT OVER THE COUNTER in usuable forms. it's farking everywhere. and also what use is polyphosphoric? i UTSFE'd it and found lots of ways to make it, no real simple uses for it
Title: yeah
Post by: r2e3 on July 10, 2004, 06:13:00 AM
just check you local hydroponics shop and you'll be laughing