PURPOSE: To uniformly and smoothly compact the surface of a raw material layer and to improve packing density and the yield of sintered lumps by providing a roll for rolling down the raw material layer between a cut plate and ignition furnace and controlling the rotating speed of the roll in such a manner that the circumferential speed of the roll is synchronized with the speed of a pallet.

CONSTITUTION: The roll 48 is brought into contact with the surface of the raw material layer 14 and is pressurized under certain rolling down force by means of a jack 46 to compact the surface layer of the raw material layer 14 at a rolling reduction (h). The above-mentioned circumferential speed V is preliminarily calculated by the equation so that the circumferential speed V of the roll 48 right under the roll 48 and the speed (v) of the pallet 4 are synchronized with each other to prevent the generation of a slip. The calculation is made by converting the speed signal calculated after the rotating speed signal of the driving motor 58 of a sintering machine 52 and the above-mentioned rolling reduction (h) are inputted to the rotating speed of the roll 48 by an inverter 58. The signal is inputted to a driving motor 50 to control the rotating speed of the roll 48. Unevenness is thereby eliminated from the surface of the raw material after the compaction and the material is uniformly compacted.