The Effects of Temperature and Mineral Acids on the Demineralization Degree of Nallihan Lignite

Gulen J., DOYMAZ İ., Pişkin S., Ongen S.

ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS, vol.35, no.3, pp.202-208, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 35 Issue: 3
  • Publication Date: 2013
  • Doi Number: 10.1080/15567036.2012.636725
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.202-208
  • Keywords: demineralization, Fourier transform infrared, lignite, mineral matter, X-ray diffraction, COAL, DESULFURIZATION, REMOVAL, ASH, MATTER, SULFUR
  • Yıldız Technical University Affiliated: Yes


Demineralization of lignites from Nallihan, Turkey, was investigated using various aqueous acids, such as HCl, HNO3, and H2SO4, which were used at the concentrations of 5 and 10 vol%, hydrofluoric acid (HF) acid solutions of 5, 10, 20, 30, and 40 vol%. The experiments were done at 20, 40, 50, and 60 degrees C temperatures in order to observe the heating effect on the removal yields. The best result was found for the sample being done experimentally with 5% HF. The ash content is decreased from 17.12 to 6.98 wt% and heating value is increased from 16,652 to 23,950 kJ/kg according to the original lignite. The yields are 59.23 and 44%, respectively. Fourier transform infrared and X-ray diffraction were used to observe the leaching effect of the mineral acids on the demineralization degree of Nallihan lignite.