Valorization of biofuel produced from citrus waste as potential collector in coal flotation: production, characterization, and flotation performance

The common collector in coal flotation is diesel. In this study, biofuel synthesized from citrus waste was produced and evaluated as a collector in coal flotation experiments. The produced biofuel was thoroughly characterized – its density, surface tension, HPLC composition, FTIR, and XPS profiles were measured and compared with diesel. Flotation tests were conducted on two coal samples (C1 and B2) under varying conditions of particle size, collector dosage, and pulp density. The results demonstrated that decreasing the coal particle size improved flotation efficiency, whereas increasing the collector dosage beyond optimal levels resulted in a decline in recovery. For sample C1, the biofuel collector achieved a recovery exceeding 95% with concentrate ash below 10%, while for sample B2, optimal recovery was approximately 83.5% with an ash content below 15%. Although biofuel showed promising performance, its selectivity was lower than that of diesel, as ash components (being hydrophilic) were more readily attached to biofuel molecules. This paper discusses the implications for sustainable mineral processing and suggests that, under proper conditions, citrus-derived biofuel could serve as a cost-effective and environmentally friendly alternative to conventional diesel collectors. Synthesis and characterization of biofuel from citrus waste was examined.The use of synthesized biofuel as a collector for the flotation of two coal samples was examined.Synthesized biofuel in coal flotation, leading to highest recoveries in similar conditions.By increasing the amount of synthesized biofuel as a collector in coal flotation, the percentage of ash in concentrate also increases.Although the synthesized biofuel has alcoholic properties, it cannot be used as a foaming agent. Synthesis and characterization of biofuel from citrus waste was examined. The use of synthesized biofuel as a collector for the flotation of two coal samples was examined. Synthesized biofuel in coal flotation, leading to highest recoveries in similar conditions. By increasing the amount of synthesized biofuel as a collector in coal flotation, the percentage of ash in concentrate also increases. Although the synthesized biofuel has alcoholic properties, it cannot be used as a foaming agent.