▎ 摘　　要

NOVELTY - The reactor has volume (Vh) that is adapted to be heated by a plasma torch to a temperature of 3000 ° C. The volume is set in an uppermost portion of the reactor. The uppermost portion is in relation to the direction of gravity force. An inlet is directed tangentially in a circular cross section of the reactor. USE - Reactor e.g. cyclone reactor. ADVANTAGE - More efficient heating of the particles of material to be heat treated can be obtained, when the fraction of energy transferred by thermal radiation is increased. The compactness of the cyclone reactor gives a very efficient heat transfer to the particles. The efficiency of the process is improved. The speed of the calcination can be increased, and the reactor can be made compact. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a heat treatment method. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the reactor.