Akademik Veri Yönetim Sistemi
International Journal of Coal Preparation and Utilization, 2026 (SCI-Expanded, Scopus)
This study proposes a physically interpretable framework for evaluating coal washability by integrating laboratory sink–float test results with image-based RGB–HSV analysis for hard coal from the Çatalağzı Coal Preparation Plant (Zonguldak) and lignite from the Amasya region. Sink–float tests indicate that Zonguldak hard coal exhibits favorable washability at lower separation densities, with relatively stable ash–yield trends up to ~1.40 g/cm3, followed by a sharp decline in separation efficiency between 1.40 and 1.60 g/cm3 due to increased near-gravity material (NGM). In this range, ash content rises rapidly while yield gains diminish, marking a critical washability threshold. In contrast, Amasya lignite shows steeper ash–yield slopes throughout most of the density range, with a narrow effective washing window around 1.40–1.55 g/cm3, indicating lower inherent washability and higher sensitivity to cut-density variations. Image analysis corroborates these findings: hard coal displays moderate-to-good washability with higher brightness values (V ≈ 60–72) and limited saturation variability (S ≈ 3–22), whereas lignite shows lower brightness (V ≈ 39–58) and broader saturation ranges (S ≈ 22–38), reflecting stronger mineral matter association and reduced separation sharpness.