Character & Purpose: Crystal block (flake / solid)，Mainly used in paper making, printing and dyeing , tanning, etc.
Packing: 25kg net PP/PE bags for flake, 150kg net iron drum for solid
Formula: Na2S
Standard:
| Item | Spec. | |||
| Fe3+:1500ppm | Fe3+:150ppm | Fe3+:80ppm/50ppm | Fe3+:30ppm/20ppm | |
| Na2S/% | 60 Min. | 60 Min. | 60 Min. | 60 Min. |
| Na2CO3/% | 5 Max. | 2.0 Max. | 2.0 Max. | 2.0 Max. |
| Water insolubles/% | 0.4 Max. | 0.2 Max. | 0.2 Max. | 0.05/0.03 Max. |
| Iron Content/% | 0.15 Max. | 0.015 Max. | 0.008/0.05 Max. | 0.003 /0.002 Max. |