8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

Nantong coal (NTC) and Laigang coal (LGC), the two typical high-sulfur coking coal in China, were investigated on their desulfurization processes with the addition of NaOH-H2O2 under microwave treatment. X-ray diffraction (XRD), inductively coupled plasma (ICP) and fourier transform infrared (FT-IR) were performed to unravel the migration of organic sulfur in the two coal. In addition, the constituents of organic sulfur and content of functional groups in both two coal were also analyzed. NTC and LGC, with the addition of NaOH/H2O2 at a volume ratio of 1:4 and microwaved at 1000 W for 10 min presented the highest desulfurization rates, that is, 22.3 and 31.75 % respectively. XRD analysis revealed that organic sulfur in the two coal was transformed into inorganic sulfur with the existence of sulfate or FeS, this transformation process inhibited desulfurization rate of the two coal. FT-IR measurement depicted that NaOH/H2O2 ratio below and above 1:4 promoted and inhabited the desulfurization rate of the two coal. Moreover, the three sulfur-bearing functional groups were reserved in the two coal with the order of S=O > -S-H- > -S-S- under the NaOH/H2O2 ratio of 1: 4, therefore, controlling of S=O in NTC and LGC is the key to improve the desulfurization rate.