The wettability of coke by pitches with different quinoline-insoluble contents

Abstract

The properties of pitch as the binder material for carbon anode manufacturing strongly affect the anode properties. Pitches show significant differences in their chemical composition depending on their origin. In this study, five coal tar pitches with different quinoline-insoluble (QI) contents were studied to understand the wettability of one calcined petroleum coke by these pitches using the sessile-drop test. The chemical properties of the coke and pitch were studied using XPS and FT-IR to investigate their wetting mechanism and their interactions. The structures of different pitches and the pitch-coke interface were characterized by optical microscopy and SEM, respectively. The results showed that not only the chemical but also the physical properties of the pitches contribute to the wettability of coke. The wettability increases with increasing heteroatom content in the pitch. The viscosity of pitch is a key parameter controlling the wetting behavior of pitch. The QI content, the solid particle size and their distribution in the pitches play a significant role in the wettability of coke by pitch.