A review on flotation of coal using mixed reagent systems

• Published in: Minerals engineering Vol. 173; p. 107217
• Main Authors: Kadagala, Mohana Rao, Nikkam, Suresh, Tripathy, Sunil Kumar
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2021
• Subjects: Anionic/Cationic/Non-ionic surfactant; Coal flotation; Collector; Emulsification; Fatty acid mixtures; Mixed reagent system; Collector; Anionic/Cationic/Non-ionic surfactant; Coal flotation; Fatty acid mixtures; Emulsification; Mixed reagent system
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2021.107217

[Display omitted] The efficiency of the coal flotation process in separating fine particles is primarily influenced by the type of reagent selected. The efforts made for improved recovery of carbonaceous material with minimal ash in clean coal are endless. Today, the coal preparation industry is striving hard through several routes to improve the clean coal recovery for sustainability. One of the efforts has been the use of mixed reagents, which has shown significant progress over the years but less understood about reagent adsorption mechanisms. The use of mixed collectors, mixed surfactants and emulsification of oily collectors with surfactants have shown tremendous advantages over the conventional approach of using individual reagents. High separation efficiencies could be due to their ability to get adsorbed quickly and selectively onto the coal surfaces. The increased opportunity for reagent adsorption is mainly due to the facilitation of reduced interfacial tension between oil and water, particularly in oxidized or low-rank coals. The present review paper summarizes the up-to-date research advancements made in the use of mixed reagent systems to improve the separation efficiency of coal flotation. Experimental and molecular dynamics simulation approaches have been adopted to enhance floatability, and reagent adsorptions are also discussed. Further, an effort has been made to compare the effects of different mixed collectors on improving the separation efficiency at the industrial level application.