Development of Microencapsulation-Hybrid Jig Separation Technique as a Clean Coal Technology
Theerayut Phengsaart,
Ilhwan Park,
Jirathpapol Pasithbhattarabhorn,
Palot Srichonphaisarn,
Chinawich Kertbundit,
Nutthakarn Phumkokrux,
Onchanok Juntarasakul,
Carlito Baltazar Tabelin,
Naoki Hiroyoshi,
Mayumi Ito
Affiliations
Theerayut Phengsaart
Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
Ilhwan Park
Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
Jirathpapol Pasithbhattarabhorn
Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
Palot Srichonphaisarn
Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
Chinawich Kertbundit
Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
Nutthakarn Phumkokrux
Department of Geography, Faculty of Education, Ramkhamhaeng University, Bangkok 10240, Thailand
Onchanok Juntarasakul
Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
Carlito Baltazar Tabelin
Department of Materials and Resources Engineering Technology, College of Engineering, Mindanao State University–Iligan Institute of Technology, Iligan City 9200, Philippines
Naoki Hiroyoshi
Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
Mayumi Ito
Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
In this study, the microencapsulation-hybrid jig separation technique was developed to improve the separation efficiency of pyrite and coal in the particle size range of 1–4 mm where conventional jig separation becomes inefficient. A hybrid jig is a gravity concentrator combining the concepts of jig separation and flotation to stratify particles based on their apparent specific gravity. Meanwhile, microencapsulation—a technique that encapsulates target materials with a protective coating—was applied to render pyrite hydrophilic and improve its separation from hydrophobic coal. The results showed that the required time for separation in the hybrid jig (0.5 min) was shorter than in conventional jig (2 min). Moreover, the effects of particle size on separation efficiency were reduced when a hybrid jig is used. However, the separation efficiency of hybrid jig separation was lower than that of the conventional jig because attachment of bubbles occurred to both pyrite and coal, which are hydrophobic. Using the microencapsulation-hybrid jig separation technique, the separation of coal and pyrite was significantly improved (~100%) because of the formation of hydrophilic iron phosphate coatings on pyrite that limited bubble attachment. This means that microencapsulation-hybrid jig separation is a promising clean coal technology that not only enhances the separation efficiency of the hybrid jig but also passivates pyrite and limits AMD formation in the tailings/rejects.
