Preliminary Evaluation of Quality and Rank of Banik Coal, Zakho, Duhok Governorate, Kurdistan Region, Iraq

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.

Evaluation of femtosecond laser-induced breakdown spectroscopy system as an offline coal analyzer

Developments in femtosecond laser induced breakdown spectroscopy (fs-LIBS) applications during the last two decades have further centered on innovative métier tie-in to the advantageous properties of femtosecond laser ablation (fs-LA) introduced into LIBS. Yet, for industrially-oriented application like coal analysis, no research has exposed to view the analytical capabilities of fs-LA in enhancing the physical processes of coal ablation and the impact into quantitative correlation of spectra and data modeling. In a huge coal market, fast and accurate analysis of coal property is eminently important for coal pricing, combustion optimization, and pollution reduction. Moreover, there is a thirst need of precision standardization for coal analyzers in use. In this letter, the analytical performance of a one-box femtosecond laser system is evaluated relative to an industrially applied coal analyzer based on five objectives/measures: spectral correlation, relative sensitivity factors, craters topology, plasma parameters, and repeatability. Despite high-threshold operation parameters of the fs system, competitive results are achieved compared to the optimized analytical conditions of the ns-coal analyzer. Studies targeting the in-field optimization of fs-LIBS systems for coal analysis can potentially provide insights into fs-plasma hydrodynamics under harsh conditions, instrumental customization, and pave the way for a competitive next-generation of coal analyzers.

Coal analysis by laser-induced breakdown spectroscopy: a tutorial review

This review article forms a guideline for LIBS contribution in coal analysis, encompassing fundamental aspects, operation modes, data processing, and analytical results. LIBS applications related to coal utilization are also highlighted (fly ash analysis and combustion monitoring).