Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: Concentrating phosphoric acid
violet sin
International Hazard
*****




Posts: 1222
Registered: 2-9-2012
Location: :14,15,9,20,1,3,15,12
Member Is Offline

Mood: doom

[*] posted on 26-9-2012 at 01:14


so, I searched first. and apologies if this is a repeat for some one.
that being said, I am also interested in phosphoric acid. as I have none in stock and I never really liked purchasing chems over the net. most of the OTC stuff I find isn't so clean.

1) so is there any way to start w/ TSP(Na3PO4) or bonemeal as my phosphates and end up with a decent clean acid? I had remembered something about bone meal or phosphate rock can be leached with con. H2SO4 yielding basically gypsum(CaSO4) and a mobile phase of concentrated H3PO4. I brought up the TSP b/c it looks like nice clean crystal, compared to crushed bones or rock. I could sacrifice some of my purified drain cleaner w/o feeling too bad.

2) also does a home based guy have any prospect for making P2O5 for dessication purposes? I am not trying to make WP with any of these chems so no worries. I read that it was good for dessication but once hydrated it wasn't easy to regenerate w/o decomp? guess having nice fresh H3PO4 outta the moisture might not be the worst thing in the world. just I like my dessicators to be regenerative. using CaCl2 mainly.


and realize I am not trying to reinvent the wheel here, just have limited reagents for sure. If it doesn't work I will wait till I can afford to buy some.
View user's profile View All Posts By User
zed
International Hazard
*****




Posts: 1628
Registered: 6-9-2008
Location: Great State of Jefferson, City of Portland
Member Is Offline

Mood: Semi-repentant Sith Lord

[*] posted on 26-9-2012 at 12:13


Mono-Ammonium Phosphate may be converted to Phosphoric Acid (or PPA) via Microwaving under Vacuum.

Repeated dehydration Cycles produce PPA (PolyPhosphoricAcid).

I don't know if P2O5 can be achieved by ordinary methods.

Somewhere in the Science Madness Archives, there are detailed discussions on the matter. Search.
View user's profile View All Posts By User
violet sin
International Hazard
*****




Posts: 1222
Registered: 2-9-2012
Location: :14,15,9,20,1,3,15,12
Member Is Offline

Mood: doom

[*] posted on 26-9-2012 at 19:47


Ya found a book to read,.. yay. and came across a quick easy one just like I had mentioned for the acid. though I am pretty sure I won't be making the P2O5 my self. mainly b/c it revolves around making P4 first, then burning it. no thanks.

I appreciate the info zed, though I am not sure I would know where to get the (NH4)H2PO4 in the first place. the decomp is low temp and vacuum isn't hard to manage, which is nice. my 12th merck said it's for a leavening agent. though I already have ~10#'s bonemeal for my garden. only $1.25/# here and I have acid. think I will take that route.

ya I'm new to posting here. been reading for over a month, almost every day. and as it turns out I had not noticed the "next page" button in lower right on the search engine so I didn't even get to look at all the threads that had pertaining info.. sorry for the quick draw on that last post.
View user's profile View All Posts By User
TheVoid
Harmless
*




Posts: 10
Registered: 5-1-2018
Member Is Offline

Mood: No Mood

[*] posted on 5-1-2018 at 23:52
azeotropic distillation


sorry for reviving such an old thread but has anyone tried azeotropic distillation? why wouldnt P-xylene work?
View user's profile View All Posts By User
Magpie
lab constructor
*****




Posts: 5830
Registered: 1-11-2003
Location: USA
Member Is Offline

Mood: Chemistry: the subtle science.

[*] posted on 6-1-2018 at 17:20


See "Phosphoric acid from calcium phosphate" in Prepublication.



The single most important condition for a successful synthesis is good mixing - Nicodem
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top