Improving low-rank coal flotation using a mixture of oleic acid and dodecane as collector

Low-rank coals (LRC) are abundant but underutilized due to their hydrophilic nature and high oxygen content, which hinder flotation efficiency. Traditional single-collector systems often result in low recovery rates and high reagent consumption. This study investigates the use of a mixed collector system comprising oleic acid (OA) and dodecane (D) to improve LRC flotation. Response Surface Methodology (RSM) was employed to optimize the dosing ratio of OA to D. Laboratory-scale flotation tests demonstrated that mixed collectors significantly enhance flotation efficiency, achieving recovery rates up to 65.5% and reducing ash values from 55.6% to 16.7%. Optimal conditions were identified at a dodecane dosage of 300 g/t and an oleic acid dosage of 255.5 g/t. The findings underscore the potential of mixed collectors to enhance coal hydrophobicity, thereby improving recovery and separation from gangue minerals. This approach offers a sustainable solution for LRC beneficiation, minimizing waste and enhancing economic viability.