isolating phosphoric acid

[fnord]

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?

[barkingburro]

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.

[Rhodium]

would fractinal distalation work?

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

[ApprenticeCook]

phosphoric is at building supply companies.

H₃PO₄ - d213^oC
so in other words if you bring it to that temp you will decompose the acid, hence screw it. Thats before it boils too.

[Nicodem]

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.

[ApprenticeCook]

thats assuming it only contains phosphoric acid and water though.

[Nicodem]

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.

[r2e3]

well - thats for silica gel

[barkingburro]

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

[r2e3]

just check you local hydroponics shop and you'll be laughing