Effect of conventional and microwave thermal treatments on floatability of low- and high-rank lignites

ABSTRACT

Thermal treatment is one of the well-known methods used before froth flotation to remove the polar groups from coal surfaces to make them more hydrophobic. In this study, the effect of conventional and microwave thermal treatments on the wettability of low and high-rank lignite was investigated using flotation experiments, zeta potential, and bubble-particle attachment time measurements, as well as hydrophilicity index analyses. The results showed that both of the thermal treatments increased hydrophobicity, and therefore floatability of the coal samples. The optimum results were achieved with conventional and microwave thermal treatment for the low and high-rank coals, respectively.

KEYWORDS:

• Lignite
• flotation
• conventional thermal treatment
• microwave
• hydrophilicity

Acknowledgments

The authors wish to thank Dr. Orhan OZDEMIR for his valuable contribution during experimental studies.

Additional information

Funding

This study was supported by the Research Fund of Istanbul University with project number: [FYL-2016-20287].

Notes on contributors

Safak Gokhan Ozkan

Safak Gokhan Ozkan graduated from Dokuz Eylul University Mining Engineering Department in 1990. He got Etibank Scholarship in 1991 and began to study in the University of Birmingham, Minerals Engineering Dept. and got M.Sc. and Ph.D degrees in 1993 and 1994, respectively. He started to work in Istanbul University Mining Engineering Dept. in 1998 and still working. During his professional career, he was also honored with Alexander von Humboldt Fellowship and Erasmus Teaching Staff Mobility.

Yasin Baktarhan

Yasin Baktarhan graduated from Cukurova University Mining Engineering Dept. in 2013. He got his M.Sc. degree in Istanbul University-Cerrahpasa Mining Engineering Dept. in 2017. He is working as a research assistant and also performing his Ph.D. studies at the same department.

Can Gungoren

Can Gungoren graduated from Istanbul University Mining Engineering Department in 2006. He started to M.Sc. education and also began to work as a research assistant at the same department in 2006. He had M.Sc. degree in 2009 and Ph.D. degree in 2016. During his Ph.D studies, he got TUBITAK scholarship in 2014 and continued his studies in the University of Utah, Metallurgical Engineering Department. He is still working as Dr. Res. Assist. at Istanbul University-Cerrahpasa Mining Engineering Department.

Ismail Demir

Ismail Demir graduated from Istanbul University Mining Engineering Department in 2002. He started to M.Sc. education and also began to work as a research assistant at the same department in 2005. He had M.Sc. degree in 2009 and Ph.D. degree in 2016. He is still working as Dr. Res. Assist. at Istanbul University-Cerrahpasa Mining Engineering Department.