Table 4 Chemical analysis of marble sludge waste.
From: Valorization of marble sludge waste in biodiesel production using a central composite design
Constituents Wt. (%) | Marble sludge waste54 | Marble sludge waste24 | Marble sludge waste Current study | Calcined marble sludge waste |
|---|---|---|---|---|
SiO2 | 0.79 | 5.02 | 8.31 | 12.55 |
Al2O3 | 0.21 | 0.14 | 0.59 | 0.89 |
Fe2O3tot. | 0.06 | 1.22 | 1.13 | 1.71 |
TiO2 | 0 | 0 | 0.01 | 0.015 |
MgO | 0.25 | 0.39 | 0.37 | 0.559 |
CaO | 55.42 | 57.5 | 53.04 | 80.13 |
Na2O | 0.1 | 0.13 | 0.2 | 0.302 |
K2O | 0.02 | - | 0.07 | 0.106 |
P2O5 | 0.06 | - | 0.08 | 0.121 |
SO3 | 0.24 | 0.06 | 2.32 | 3.505 |
SrO | 0.04 | 0 | 0.077 | 0.116 |
L.O.I | 42.28 | 34.8 | 30.04 | - |
