the oxidative treatment and will usually constitute from about 40 to about 55 percent of the total time utilized in the overall process of the invention conversion of the heat soaked carbonaceous feedstock to mesophase pitch is completed by subjecting the oxidized and heat soaked feedstock to elevated temperatures usually at atmospheric pressure with inert gas sparging and with agitation as desired the operating conditions employed which are similar to those used in the oxidation step include temperatures in the range of about 350 u00b0 c to about 500 u00b0 c and preferably from about 370 u00b0 c to about 425 u00b0 c the heating step is carried out over a time period equal to or less than that employed in the heat soak step usually between about 4 and about 10 hours depending on the temperature employed preferably the inert gas sparging phase of the process constitutes from about 20 to about 0 percent to the total time utilized in the overall process a variety of inert gases may be used as a sparging material including nitrogen argon carbon dioxide helium methane carbon monoxide and steam sparging is carried out at a gas rate of at least 0 1 scfh per pound of feedstock and preferably from about 1 0 to about 20 scfh per pound and usually at the same.