Compression of Aggregates of Acid-Leached Coal Gangues: Implications for Coal Mine Backfill

Table 1

Material compositions of the gangues in the coal mine (%).

Samples	Quartz	Kaolinite	Illite	Mixed layer of illite and smectite	Smectite	Chlorite	Feldspar	Calcite/	Noncrystalline substance	Sum
No. 1	37	35	12	6	1	2	1	0.5	4	98.5
No. 2	36	35	10	8	0.8	3	0.9	0.4	3	97.1
No. 3	38	34	13	5	1.2	1	0.9	0.6	5	98.7
Average	37	34.7	10.7	7.3	1.0	2	0.9	0.5	4	98.1