Geology and combustion perspectives of Pakistani coals from Salt Range and Trans Indus Range

Abundant availability of low rank coals in some developing countries has a great potential for socio-economic development. Pakistan, as a developing country, has taken a number of initiatives some of which are at an advanced stage. Thus, a critical study of regional and local geology of Salt Range and Trans Indus Range coals located in the Kohat–Potwar geologic province is presented in this paper. Permian coal is the oldest coal, which is located in the Western Salt Range in limited quantity while Palaeocene coal is the younger coal and it is mined from the Hangu and Patala formations. The Palaeocene coal is available in abundance and is mined in the Eastern and Central parts of the Salt Range and Trans Indus Range. Additionally, this study presents the thermo-chemical analyses of the coal samples collected from thirty coal mines of Salt Range and Trans Indus Range. The samples were analyzed for ash composition, ash fusion temperatures (AFT), proximate analysis, ultimate analysis and calorific value from two different Labs, i.e. SGS Pakistan and Changsha University of Science and Technology (CUST), China. The average AFT of the samples analyzed is > 1350 °C, which reveals that the coal is non-slagging. On average the coal has low slagging index, medium fouling index, good combustion characteristic parameters and indices. The coal samples have high ash (14–50%), ultra-high sulfur (3.3–11.1%), low moisture (3–10%), high volatile matter (VM, 24–41%), low carbon (23–57%) with low to medium gross calorific value (GCV, 10.2–25.7 MJ/kg). The data gathered from an extensive campaign is compared with the already published data. The study has provided a knowledge on utilization of coal reserves to meet the projected energy demand in Pakistan as well as in other developing countries