Sodium Tripolyphosphate (STPP)

Specifications

Criteria Specifications
Appearance Free flowing white powder without any visible contamination
Odour The material should have no noticeable malodour
P2O5 - content as is 56% Min
STPP - content as is 94% Min
Other Phosphates 6% Max
Temperature Rise Test (TRT) 10-14°C
Phase I Content 16-32%
Volatile Matter (loss at 135°C - 4h) 0.5-1%
Insoluble matter in water 0.1% Max
Sodium Sulphate Content 1.5% Max
Sodium Chloride Content 0.5% Max
Fluoride Content 0.3% Max
Colour values:

L

a

b

95 Min

-2.5 - 2.5

0 - 5

Bulk Density 700 - 1000 g/l
R.O.H:

After 1mn

After 5 mn

81-88°C

85-92°C

Particle Size:

>1000 microns

>500 microns

>150 microns

>60 microns

0.2% Max

2% Max

15% Max

50% Max

pH (1% solution) 9.4 - 10.2
Trace Metals:

Cr

Co

Ni

Fe

Mg + Ca

5 ppm Max

5 ppm Max

5 ppm Max

100 ppm Max

150 ppm Max