PURPOSE: To shorten the treating time and to save thermal energy by agitating and/or oscillating an oil-containing material in a process for separating and recovering oil and inorganic substances from an oil-containing powder of various inorganic substances.

CONSTITUTION: An oil-containing powder of various inorganic substances (e.g. an iron powder containing lubricating oil, generated due to the abrasion of rolling-mill bearings) is, for example, put into a heating chamber 4 through a charge port 1 and dispersed throughout the interior of the chamber 4 with rotating blades 6 attached to a combustion tube 3 which rotates with a drive unit 8. The temperature in the chamber 4 is raised by means of a combustion furnace 9, a heating burner 10, and rotating heat exchange blades 5. When the temperature of the oil-containing material reaches 400-500°C, the oil evaporates. The evaporated oil is liquefied in a liquefying tube and collected in an oil collecting chamber 11. Part of the liquefied oil is sent to the heating burner 10. On the other hand, the inorganic substance from which oil has been evaporated is recovered through an outlet 16. Thus the combustion tube 3 is rotated with the drive unit 8 so that an oil-containing material is agitated and/or oscillated by means of the rotating heat exchange blades 5 and rotating blades 6 both attached to the combustion tube 3 to thereby realize efficient reclamation of the oil-containing material.