Geochemical Analysis Of Coal In Hangu Formation, Orakzai Agency, Khyber Pakhtunkhwa, Pakistan

Abstract

The present study emphasizes on geochemical analysis of coal in the Hangu Formation from Orakzai Agency KP, Pakistan. The geochemical analysis includes proximate, ultimate, major, trace and rare earth elements analysis were conducted. The proximate analysis consists of calorific values by Bomb calorimeter, volatile matter, ash content and moisture content following ASTM methods. The ultimate analysis was conducted to determine the concentration of total carbon and sulphur. The proximate analysis shows moisture content ranging from 2.5 to 11.76%, volatile matter from 10.34 to 36.70%, ash content ranging from 14.71 to 22.77%, fixed carbon ranging from 43.44 to 67% and calorific value ranging from 10516 to 12829 Btu/lbs. The total carbon ranges from 44.73 to 90.66 % and the total sulphur ranges from 1.45 to 16.33 %. Major oxides analysis shows that Al2O3 ranges from 0.12 to 1.69%, CaO ranging from 0.01 to 1.50%, Fe2O3 ranging from 0.13 to 7.69%, K2O ranging from 0.01 to 0.34%, MgO ranging from 0.01 to 0.35%, Na2O ranging from 0.02 to 0.10% and TiO2 0.02 to 0.64%. The trace elements analysis shows that Co ranges from 3.94 to 27.78 ppm, Cr ranges from 16.51 to 82.84 ppm, Cu ranges from 8.35 to 34.23 ppm, Ni ranges from 14.32 to 41.32 ppm, Pb ranges from 0.55 to 23 ppm and Zn ranging from 11.79 to 72.31 ppm. The rare earth elements analysis shows that La ranges from 1.05 to 11 ppm, Lu ranges from 0.04 to 1.43 ppm, Nd ranges from 1.12 to 10.91 ppm, Sc ranges from 0.11 to 6.78 ppm, Y ranges from 2.83 to 7.75 ppm, Yb ranging from 0.54 to 1.14, LREY is 10.27 ppm, HREY is 1.52 ppm and MREY is 6.20 ppm. It is concluded that the coal of Orakzai agency ranked as high volatile A to C Bituminous coal has good calorific value with substantial thermal energy potential, high ash and sulphur content can create problems during its utilization in slagging furnace, slagging gas generator potentially leading to environmental damage while sulphur can also affect human health. The high concentration of major oxides Fe2O3 and Al2O3 shows the presence of pyrite and Kaolinite. The high concentration of trace elements such as Cu, Co, Cr, Ni, and Pb in the studied coal samples has severe impacts on human health. These trance elements can cause gastrointestinal diseases, liver damage and neuromuscular disorders. These coal samples are not enriched with rare earth elements so don’t act as a source of rare elements.