Abstract: Vacuum distillation residue oil having a Conradson carbon value of 5 to 40% and a specific gravity of 0.9 to 1.10 is thermally cracked in the presence of iron ore particles in fluidized state in a thermal cracking reactor thereby to produce light oils and cracked gases and to form by-product carbon, which is caused to deposit on the iron ore particles, which are then transferred to and heated at 800.degree. C. to 1200.degree. C. in a reducing furnace to be reduced in a solid state reaction, into sponge iron. Thus, heavy oil is thermally cracked and sponge iron is produced by an economical, integrated process.

Abstract: An effective and regenerable oil adsorbent is obtained from a pitch-like substance formed by heat-treating a heavy hydrocarbon oil to such an extent that the volatile matter content thereof is about 10% by weight to about 60% by weight, preferably about 30 to about 50% by weight. By using this oil adsorbent, oil-removing purification treatment of oil-contaminated water can be effectively achieved with economical advantages.

Abstract: High quality coke is prepared by calcining green coke obtained by the delayed coking process at a temperature lower than the customarily adopted calcination temperature, once cooling the coke and then calcining the coke at a temperature within the customarily adopted calcination temperature range.

Abstract: An effective and regenerable oil adsorbent is obtained from a pitch-like substance formed by heat-treating a heavy hydrocarbon oil to such an extent that the volatile matter content thereof is about 10% by weight to about 60% by weight, preferably about 30 to about 50% by weight. By using this oil adsorbent, oil-removing purification treatment of oil-contaminated water can be effectively achieved with economical advantages.