premium coke

https://doi.org/10.1351/goldbook.P04814
An extremely well graphitizing carbon with a high degree of optical
anisotropy
(isochromatic areas of optical texture above about 100 μm) and which is characterized by a combination of the following properties which differ significantly from those of
regular coke
: high real density, low reversible thermal expansion and low ash content combined, in most cases, with low sulfur content.
Note:
Premium
coke
is mainly produced from tars or residues from petrochemistry by the
delayed coking process
. Also, refined
coal tar pitches
are used as precursors for premium
coke
production.
Source:
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 501 [Terms] [Paper]