Effects of Single and Mixed Collectors on Low-Grade Coal Flotation: In the Case of Gamo Zone Coal, Southern Ethiopia

This study investigated the effectiveness of single and mixed collectors in enhancing the flotation efficiency of low-grade coal from the Gamo region of Ethiopia, focusing on recovery rates and ash content. The research aimed to address the challenges posed by high ash content and impurities in Ethiopian coal, which limit the industrial application. Through controlled laboratory experiments, the performance of single collectors (kerosene, diesel oil, and oleic acid) and mixed collectors in varying dosages was evaluated. The Finding revealed distinct performance characteristics among the collectors. Kerosene demonstrated higher recovery rates (33.7%) but moderate ash content (27.2%), while oleic acid prioritized purity (lowest ash content of 24.9%) at the expense of recovery (27.3%). Diesel oil showed intermediate results. Mixed collector formulations further highlighted the trade-off between recovery and ash content. For instance, the balanced triple-mixed collector C13 (kerosene, oleic acid, and diesel oil in equal parts) achieved a competitive recovery rate of 55.2% with acceptable ash levels (33.7%). In contrast, formulations with higher oleic acid content (C11) yielded the lowest ash content (32%) but reduced recovery (44%). The study underscored the inverse relationship between recovery and ash content, emphasizing the need for tailored collector blends based on specific industrial priorities. For yield-focused processes, Diesel-rich blends like C10 (56.3% recovery) are recommended, while purity-focused applications benefit from oleic acid-dominant mixtures like C11. The balanced C13 formulation emerged as a practical choice for scenarios requiring a middle ground.