Water soluble aluminum compound as Al2O3 percentage by mass, min
16.0
15.0
7.5
4.
pH of 5% aqueous solution, min
2.7
2.7
2.7
5.
Basicity (as Al2O3), % by mass, Max **
0.5
0.5
0.25
6.
Additional requirements for material required for purification of water
7.
Lead (as Pb) parts per million, max
30
30
15
8.
Arsenic (as As2O3) parts per million
6
6
3
* soluble iron compounds (as Fe) , percent be mass , Max permissible for water purification purposes only shall be 1.0 for Grades 1 and 2 and 0.5 for Grade 3
** the material of Grade 2 can also be supplied as having free acidity (as H2SO4) of 0.5% by mass, Max, if required by the purchaser, the pH in this case shall not be less than 2
Chemical composition of Non-Ferric Alum
Characteristic
Requirement
Technical Grade
Pure Grade
AR Grade
1.
Insoluble matter % by mass, Max
0.30
0.02
0.005
2.
pH (of 5% Solution), min
2.8
2.9
2.2
3.
Heavy metals (as pb), parts per million, max
-
4
10
4.
Iron (as Fe), percent by mass, max
0.01
0.004
0.002
5.
Chlorides
-
-
to pass test
6.
Arsenic (as As2O3) parts per million
-
8
5
7.
Ammonium Salts (as NH3), percent by mass, max
-
0.025
0.025
8.
Aluminum (as Al2O3), percent by mass
17 min
16.6 - 17.6
16.6 - 17.6
9.
Sodium (as Na) percent by mass, max
-
-
0.05
10.
Potassium (as K) percent by mass, max
-
-
0.01
Uses: Technical Grade (TECH) – used as a mordant in the dyeing of textiles and as a loading material for better grades of paper
Pure Grade B – used in pharmaceutical preparations and where pure grade of the material is required namely for clarifying oils and fats , preparation of aluminum resonates and other pure aluminum salts
Analytical reagent (AR) – for use as a reagent in chemical analysis
