Abstract
This study aims to evaluate the rank (or grade) and economic value of so–called coal horizons outcropping in the vicinity of Banik and Shiranish-Islam villages of Zakho District, Duhok Governorate. These coal-like beds (locally known as Banik Coal) make up few meters within the upper part of the Jurassic Naokelekan Formation. The evaluation was mainly based on standard chemical tests of coal (proximate and ultimate analyses) achieved in foreign and local laboratories. The test results were assessed according to the standard coal tests introduced by the American Society for Testing and Materials (ASTM). The latest stratigraphic studies revealed that the presumable coal horizons were thin beds of limestone and dolomitic limestone alternated with frequent shales all impregnated with bituminous materials, mostly of hydrocarbon source. The bituminous beds were traced in both upper and lower parts of Naokelekan Formation. The standard proximate coal analysis has shown low percent of fixed carbon and high percent of volatiles and ash which support the hydrocarbon source of these bituminous beds. Consequently, it would be difficult to classify these bituminous beds similarly to the standard coal ranks of ASTM. The high values of mineral matter display the dominance of minerals rather than the carbon in the local samples. However, the Gross Calorific Value (heating value) of these beds would imply that they can be used as relatively poor quality source of fuel. Besides, the exploitation of Banik coals would be influenced by the cost of extraction (or mining), the expected prices of produced coal, and the prices of alternative sources of energy.