Table 2.
Textural parameters for the magnetic lignite and magnetic char after high-energy ball milling. Data for the natural lignite sample and the coal char are also presented. Specific surface area (SBET) and the CBET constant were calculated from the BET isotherm, total pore volume (Vtot) was estimated from the adsorbed gas volume at a relative pressure near 1, and the volume of micropores and the external surface (Sext) were determined from a t-plot.
| Sample | SBET (m2/g) | C BET | Vtot (cm3/g) | Vmicro (cm3/g) | Sext (m2/g) |
|---|---|---|---|---|---|
| Lignite | 1.0 | 41.2 | 0.0099 | 0 | 1.0 |
| Char | 1.8 | −350.5 | 0.0084 | 0.0019 | 0 |
| Magnetic lignite | 2.3 | 69.1 | 0.0159 | 0 | 2.2 |
| Magnetic char | 10.6 | −343.5 | 0.0415 | 0.0024 | 5.3 |