Formula and Molecular Weight
(NH4)10[H2W12O42]·4H2O with a molecular weight of 3132.
| Chemical Analysis |
Theoretical |
Spec |
Typical Analysis |
| WO3, % |
88.8 |
87.0 min. |
89.50 |
| Ignition Loss at 750° C in Air |
11.2 |
13.0 max. |
10.70 |
Ammonium Paratungstate decomposes above 300° C to form stable tungstic oxide (WO3).
| Impurity Content |
Carbide Grade Maximum % |
Wire Grade Maximum % |
| Aluminum |
0.002 |
0.002 |
| Copper |
0.001 |
0.0003 |
| Iron |
0.003 |
0.002 |
| Molybdenum |
0.006 |
0.002 |
| Silicon |
0.004 |
0.001 |
| Sodium |
0.002 |
0.002 |
| Calcium |
0.002 |
0.001 |
| Arsenic |
|
0.002 |
| Potassium |
|
0.001 |
| Tin |
|
0.001 |
| Phosphorous |
|
0.002 |
Physical Properties
Approximate Average Particle Size (Fisher Sub-Sieve Size): 21-50 micrometers.
Sieve Analysis: 100% will pass through U.S. Standard 40-mesh screen. Minimum 70% will pass through U.S. 100-mesh screen.
Typical Sieve Analysis:
| -40 |
100% |
| -60 |
99% |
| -100 |
85% |
| -200 |
40% |
| -325 |
20% |
Approximate Bulk Density (Scott Volumeter): 35-55 g/in3