Electrochemical Study of Demineralized Bituminous Coal by Alkali-Acid Leaching Assisted Low-Frequency Ultrasonication
Keywords:
coal, demineralization, alkali-acid leaching, electrochemical, ultrasonicationAbstract
This paper describes experimental research on alkali-acid leaching treatment on bituminous coal assisted by low-frequency ultrasonication and investigates its influence on the coal's specific capacitance. In order to describe the grade of raw coal, approximate and ultimate analyses were utilised. As a leachant, NaOH and H2SO4 were utilised. The coal samples were leached twice with NaOH and H2SO4 at 37 kHz ultrasonic frequency. The concentration ratio of NaOH to H2SO4 was 1:2, with NaOH concentrations varying between 5 and 10 weight percent. With increasing leachant concentration, Fourier Transform Infrared (FTIR) spectroscopy revealed a rise in mineral band transmittance. Specific capacitance (CS) of leached coal in 3M KOH electrolyte increased in proportion to the concentration of leachant. Using 10% NaOH and a scan rate of 5 mV/s, the SC value of leached coal was 4.87 F/g.
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