A process is disclosed for producing needle coke from heavy atmospheric
distillation residues having sulfur no more than 0.7 wt %, which process
involves the steps of heating the feedstock to a temperature in the range
of 440 to 520.degree. C. for thermal cracking in a soaking column under
pressure in the range of 1 to 10 kg/cm.sup.2 to separate the easily
cokable material, separating the cracked products in a quench column and
a distillation column and then subjecting the hydrocarbon fraction from
the bottom of the quench column and a hydrocarbon fraction having a
boiling point in the range of 380 to 480.degree. C. from the distillation
column and/or any other suitable heavier hydrocarbon streams in a
definite ratio depending on certain characteristic parameters to thermal
cracking in a second soaking column at a temperature of 460 to
540.degree. C., pressure in the range of 2 to 20 kg/cm.sup.2 in presence
of added quantity of steam for formation of a mesophase carbonaceous
structure which on steam stripping and cooling forms a solid crystalline
coke suitable for manufacturing of graphite electrode of large diameter
having co-efficient of thermal expansion lower than
1.1.times.10.sup.-6/.degree. C. measured on graphite artifact in the
temperature range of 25 to 525.degree. C.