Table 1. Characterization of solid industrial residues from the paper and pulp industry (R1–R4)a.
| Lime mud (R1) | Green liquor sludge (R2) | Electrostatic precipitator dust (R3) | Lime dregs (R4) | |
|---|---|---|---|---|
| Element composition (% w/w) | ||||
| Mg | 1.13 ± 0.09 | 4.96 ± 0.08 | 1.39 ± 0.03 | 1.56 ± 0.12 |
| Al | 0.10 ± 0.01 | 0.32 ± 0.01 | 0.10 ± 0.00 | 0.97 ± 0.04 |
| Si | 0.17 ± 0.01 | 0.60 ± 0.01 | 0.20 ± 0.02 | 0.54 ± 0.04 |
| P | 0.53 ± 0.01 | 0.17 ± 0.00 | 0.50 ± 0.00 | 0.30 ± 0.00 |
| S | 0 | 1.62 ± 0.00 | 0.14 ± 0.03 | 0.00 ± 0.00 |
| K | 0 | 0.40 ± 0.00 | 0.00 ± 0 | 0 |
| Ca | 38.42 ± 0.10 | 29.98 ± 0.10 | 37.74 ± 0.53 | 37.8 ± 0.86 |
| Mn | 0.03 ± 0.00 | 1.35 ± 0.02 | <0.2 | <0.2 |
| Fe | 0.03 ± 0.03 | 0.35 ± 0.01 | <0.2 | 0.17 ± 0.00 |
| Ni | <0.2 | <0.1 | <0.1 | <0.2 |
| Particle size (μm) | ||||
| P size (μm) | 13.99 | 16.75 | 7.3 | 23.1 |
| Chemical composition (% w/w) | ||||
| CaCO3 | 96.1 | 75.0 | 94.0 | 90.8 |
| CaO | N.D | N.D | N.D | 2.1 |
| MgSO4 | N.D | 6.1 | N.D | N.D |
| MgO | N.D | 8.1 | N.D | N.D |
| Other phases | 3.9 (metal oxides, alumino-silicates) | 10.5 (alumino-silicates, metallic oxides, carbonides) | 6.0 (silicates, oxides) | 7.1 (silicates, metal oxides) |
| Percentage dry matter (% w/w) | ||||
| 83.4 ± 0.9 | 51.5 ± 1.4 | 96.4 ± 1.1 | 93.2 ± 2.4 | |
a
N.D: not determined.