Parameter Standard curve of coal^{(1)} QC_{coal} ^{ (2)} Linear least squares regression equation Correlation coefficient (
) Sulfur weight (%) Recovery yield (%)^{(3)} Dosing time (sec) 90 Y = 1.544 × 10^{−6} X + 3.394 × 10^{−3} 0.9992 3.14 ± 0.06 102.36 ± 2.58 120 Y = 1.615 × 10^{−6} X + 4.747 × 10^{−3} 0.9993 3.13 ± 0.07 101.91 ± 2.30 150 Y = 1.604 × 10^{−6} X + 7.508 × 10^{−4} 0.9999 3.05 ± 0.10 99.17 ± 2.84 Temperature of combustion tube (°C) 1120 Y = 1.605 × 10^{−6} X + 8.215 × 10^{−4} 0.9997 3.13 ± 0.06 102.01 ± 1.85 1150 Y = 1.615 × 10^{−6} X + 4.747 × 10^{−3} 0.9993 3.13 ± 0.07 101.91 ± 2.30 1180 Y = 1.586 × 10^{−6} X + 1.126 × 10^{−3} 0.9985 3.03 ± 0.03 98.68 ± 1.14 Temperature of reduction tube (°C) 850 Y = 1.621 × 10^{−6} X + 9.226 × 10^{−5} 0.9997 3.12 ± 0.06 102.01 ± 1.75 900 Y = 1.615 × 10^{−6} X + 4.747 × 10^{−3} 0.9993 3.13 ± 0.07 101.91 ± 2.30 950 Y = 1.649 × 10^{−6} X − 1.288 × 10^{−3} 0.9996 3.00 ± 0.02 97.97 ± 0.87