|
ITEMS
|
STANDARD
|
RESULT
|
Orthophosphoric acid is industrially obtained by treating apatite with sulfuric acid. Oxidizing phosphorus with nitric acid yields a purer form of phosphoric acid; typically a thick solution ranging from 83% to 98% concentration.
Further concentration produces colorless crystals. Phosphoric acid readily deliquesces in air; Heating causes gradual dehydration to form pyrophosphoric acid, and further dehydration yields metaphosphoric acid. Phosphoric acid readily self-associates into various compounds such as pyrophosphoric acid or triphosphoric acid. |
|
|
H3PO4
|
85% Min
|
85.1
|
||
|
Heavy Metals as Pb
|
5PPM Max
|
4PPM
|
||
|
Arsenic as As
|
0.5PPM Max
|
0.2PPM
|
||
|
Fluoride as F
|
10PPM Max
|
5PPM
|
||
|
H3PO3
|
120PPM Max
|
100PPM
|
||
|
Chlorides
|
5 PPM Max
|
2 PPM
|
||
|
Sulphates
|
5 PPM Max
|
2 PPM
|
||
|
Fe
|
5 PPM Max
|
2 PPM
|
||
|
Color/Hazen
|
20 Max
|
9
|
||