Coal beneficiation by tribo-electrostatic method depends on tribo-charging attributes of coal and ash formingminerals. The tribo-electrification behaviour of pyrite mineral contacted with different materials has been investigatedthrough charge measurements and the charge acquisition is probed through surface energy calculations from liquid contactangle data. Liquid contact angle on pyrite powder after tribo-electrification is determined by Krüss tensiometer usingWashburn’s equation. The sample holder in tensiometer is specially fabricated with different materials serving the purposeof tribo-electrification and contact angle measurement. The acid and base parameters of pyrite surface determinedwith van Oss acid-base approach using liquid contact angle data after tribo-electrification with different materials revealedthe charging phenomena and electron transfer mechanism. The results showed an explicit correlation between the chargegenerated by pyrite powder and surface acceptor (acid)-donor (base) electronic state underlying the work functions of contactingsurfaces. Thus a method for characterising the changes in surface energetic structure of solids during contact electrificationin terms of surface acid-base parameters has been illustrated for the first time.
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