Abstract: The invention provides methods, apparatuses, and rotary furnaces for continuously manufacturing charcoal having a carbon content by weight which is greater than 95% of the total weight of carbon and volatile matter. Fragments of vegetable material contained in a hopper are inserted into a rotary furnace, with the transit time of the fragment through the furnace lying in the range 45 minutes to 60 minutes. The temperature in the front zone of the furnace where carbonization takes place is maintained in the range 900.degree. C. to 1000.degree. C. The furnace is heated by an axial burner which burns both combustible gases due to pyrolysis of the vegetable matter fragments and a second fuel. The charcoal falls into a hopper, from which it passes through a cooling chamber where it is colled by sprayed jets of water, after which it is extracted by an endless screw extractor. One application of the invention is manufacturing charcoal for making activated charcoal free from inorganic impurities.