Analysis of Carbon Contents and Heavy Metals in Coal Samples Using Calibration-free LIBS Technique

Table 2

Quantitative analysis of major elements in coal samples collected from coal mining sites across Pakistan and one Chinese sample.

The concentration of major elements in coal samples (g/kg)
Elements	Chinese	Lakhra	Duki	Makerwal	Thar
Al	5.3 ± 0.2	14 ± 1.1	4.3 ± 0.2	9.1 ± 0.4	15 ± 0.7
C	718 ± 23	665 ± 17	701 ± 22	642 ± 21	644 ± 27
Ca	42 ± 1.4	44 ± 2.1	13 ± 0.3	41 ± 1.3	37 ± 1.2
H	34 ± 1.2	49 ± 2.1	42 ± 1.2	35 ± 1.1	52 ± 1.4
N	7.2 ± 0.2	20 ± 1	12 ± 0.2	11 ± 0.3	13 ± 1.1
O	188 ± 6	193 ± 6	225 ± 9	194 ± 6	222 ± 7
S	2.1 ± 0.2	7.3 ± 0.3	1.1 ± 0.1	52 ± 2.1	5.2 ± 0.2
Si	1.2 ± 0.1	2.1 ± 0.2	1.3 ± 0.1	5.4 ± 0.2	7.1 ± 0.4