A semi-strand cooling method and a high temperature boiler exhaust gas circulation method were employed at the Wakayama No. 4 sintering plant in 1985. Since then, the productivity has increased and the medium pressure steam recovery has been achieved. However the productivity of the Wakayama No. 4 sintering plant was primarily affected by the cooling speed of the sinter cake, so the following countermeasures were taken : the reduction of melting index of the sinter feed, the operation with high basicity and the usage of coarse limestone. Through these improvements, Wakayama No. 4 sintering plant has been in stabl operation with high productivity (_??_37 t/m2/d).
