Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Physical-volumetric parameters of the coal cylindrical samples: a) at initial state; b) after imbibition
a) | ||||||||
---|---|---|---|---|---|---|---|---|
Sample | w0 | γ0 (kN/m3) | Gs* | γd (kN/m3) | e0 | Sr | θ | drying procedure / time (day) |
1 | 15.9% | 8.4 | 1.2 | 7.2 | 0.63 | 30% | 0.12 | hygroscopic / - |
3 | 9.7% | 8.5 | 1.2 | 7.8 | 0.52 | 23% | 0.08 | free drying / 2 |
2 | 7.7% | 8.5 | 1.2 | 7.9 | 0.49 | 19% | 0.06 | free drying / 4 |
4 | 0.0% | 7.7 | 1.2 | 7.7 | 0.52 | 0% | 0.00 | oven drying at 105°C / 2 |
Matric suction values measured along the central vertical of the prototype model: a) at initial state; b) during the drying phase
a) | ||
---|---|---|
ch1 | ch2 | ch3 |
(kPa) | (kPa) | (kPa) |
61.9 | 56.3 | 65.1 |
Hydraulic function parameters: a) at the first infiltration test; b) at the second infiltration test
a) | ||||||
---|---|---|---|---|---|---|
θr | θ0 | α | a=1/α | n′ | ks | l |
(kPa)−1 | (kPa) | (m/s) | ||||
0.0165 | 0.3014 | 1.670 | 0.598 | 1.703 | 8.0E-04 | 1 |
Compositional data of the coal
Determination | Standard/Method | Weight (%) | Note |
---|---|---|---|
Moisture in the Analysis Sample* | ISO 11722:1999 | 11.1 | Air Dried Basis |
Ash Content* | ISO 1171:2010 (E) | 5.8 | As Received Basis |
Volatile Matter* | ISO 562:2010 (E) | 37.4 | As Received Basis |
Fixed Carbon* | By calculation | 42.3 | As Received Basis |
Carbon** | ASTM D 5373-08 | 65.7 | Air Dried Basis |
Hydrogen** | ASTM D 5373-08 | 4.4 | Air Dried Basis |
Nitrogen** | ASTM D 5373-08 | 1.3 | Air Dried Basis |
Sulphur** | ASTM D 4239-10 | 0.8 | Air Dried Basis |
Oxygen** | By calculation | 10.7 | Air Dried Basis |
Hydraulic properties of the Indonesian coal in comparison to other granular materials
Material | a (kPa) | ks (m/s) |
---|---|---|
Indonesian Coal – virgin state | 0.60 | 8.0E-4 |
Indonesian Coal – after collapse | 1.23 | 1.0E-5 |
Silty Clayey Sand | 0.63 | 1.58E-6 |
Pervious Concrete – different mixtures | 3.07 | 2E-4 |
Sand | 10 | 3E-4 |
WRC parameters for the drying phase following the first imbibition stage
θr | θ0 | α | a=1/α | n′ |
---|---|---|---|---|
(kPa)−1 | (kPa) | |||
0.0165 | 0.3014 | 0.812 | 1.231 | 1.703 |
Physical-volumetric state of the coal in the prototype model during the drying phases
After 7 days of drying at room temperature | |||||
---|---|---|---|---|---|
w | W (N) | Wd(N) | H (m) | V (m3) | Gs* |
17.70% | 2096 | 1781 | 0.895 | 0.2238 | 1.20 |
γ (kN/m3) | γd (kN/m3) | e | n | Sr | θ |
9.37 | 7.96 | 0.48 | 0.32 | 44.39% | 0.144 |
w | W (N) | Wd (N) | H (m) | V (m3) | Gs* |
16.73% | 2082 | 1781 | 0.895 | 0.2238 | 1.20 |
γ (kN/m3) | γd (kN/m3) | e | n | Sr | θ |
9.31 | 7.96 | 0.48 | 0.32 | 41.97% | 0.136 |
Physical-volumetric parameters of the coal in the prototype model: a) at initial state; b) after volumetric collapse
a) | |||||
---|---|---|---|---|---|
w0 | W0 (N) | Wd(N) | H (m) | V (m3) | Gs* |
11.21% | 1984 | 1784 | 1.002 | 0.2505 | 1.20 |
γ (kN/m3) | γd (kN/m3) | e | n | Sr | θ |
7.92 | 7.12 | 0.65 | 0.39 | 20.61% | 0.081 |