Application of Coal Ash to Postmine Land for Prevention of Soil Erosion in Coal Mine in Indonesia: Utilization of Fly Ash and Bottom Ash

Table 1

Physical and chemical properties of the coal ash.

Samples	FA1	BA1	FA2
Physical properties
Specific gravity (g/cm^3)	2.10	1.96	2.07
Chemical composition (mass%)
SiO2	30.93	44.56	67.39
Al2O3	13.30	16.48	18.70
FeO	5.93	7.60	4.16
MgO	2.24	2.73	1.10
CaO	1.82	2.34	2.87
Na2O	0.16	0.46	0.67
K2O	1.54	1.69	1.23
SO3	1.21	7.22	0.22
H2O	41.02	22.32	1.97