This paper deals with the investigation of structural parameters of differe
nt cokes: petroleum coke, pitch coke, pure metallurgical coke, and metallur
gical coke produced from coal with the addition of atmospheric residue and
coal tar pitch. Crystallographic parameters (crystallite height, L-c and in
terlayer spacing, d(002)) were measured by X-ray diffraction after heat tre
atment at 1200, 1600, 2000 and 2400 degrees C (heating rate 10 degrees C/mi
n, heating time 4 h). Surface morphology was determined by means of scannin
g electron microscopy (SEM analysis) at 1200 and 2400 degrees C. The result
s show that temperature and the type of coke have an important effect on th
ese structural parameters. Maximum L-c values and lowest d(002) values were
obtained for the pitch coke and the coke produced from coal with 20 wt.% c
oal tar pitch addition heated at 2400 degrees C. Differences in crystallogr
aphic parameters of the cokes examined also become manifest through their s
urface morphology. After heat treatment at 2400 degrees C, the pitch coke a
nd the coke produced with addition of coal tar pitch brought about the deve
lopment of more lamellar structural components. (C) 1999 Elsevier Science L
td. All rights reserved.