PURPOSE: To obtain a particulate fuel which can be stably burned, by kneading oil- contg. sludge with an inorg. cement contg. sodium alkylbenzenesulfonate, followed by crushing into particulate material.

CONSTITUTION: Oil-contg. sludge is kneaded with an inorg. cement contg. a surfactant primarily composed of sodium alkylbenzenesulfonate. The resulting mixture is naturally cured in a curing frame and then crushed to obtain particulate fuel. The sludge to be used is petroleum tank sludge, tanker bilge sludge, a variety of waste oils in the chemical industry, etc. The inorg. cement is a water- or oil-holding clay mineral such as pozzolanic clay, shale or acid clay in addition to the portland cement. It is preferred to use the portland cement in combination with a pozzolanic material or a clay mineral, in the presence of a large amt. of oil.