The invention relates to a device for the thermal processing of divided solids, that comprises at least one transfer member (17) having a longitudinal axis (X) and a helical portion (18) mounted so as to rotate about said longitudinal axis in a tubular housing (11), wherein said helical portion (18) has a heating surface defining a heating transfer means. According to the invention, the tubular housing (11) has inner walls (41, 42) made of a refractory material, and the helical portion (18) of the transfer member (17) further defines a means for heating the inner walls (41, 42) to a temperature sufficient so that the inner walls themselves define a means for heating by radiation the mass of divided solids flowing in said tubular housing (11).