Abstract: The raw material in a raw material feeding apparatus of a melting cast installation is supplied, through a guide cylinder vertically mounted inside a furnace wall, towards a melting pot of a casting apparatus. A plurality of plasma arc torches, for heating the raw material, are positioned on the upper rotatable half of said furnace wall and are radially arranged around the axis of said guide cylinder with front ends thereof directed individually towards said melting pot. The raw material feeding apparatus may consist of a rotatable cylindrical drum laid substantially horizontally and a helical compartment wall to define a raw material path inside said cylindrical drum. A cylindrical limiter may be vertically mounted, inside said guide cylinder, for vertical movement so as to form an adjustable annular path for raw material between said limiter and the internal surface of said guide cylinder.