The productivity of Rautaruukki blast furnaces has been continuously i
mproved by developing burden materials and blast furnace operation pra
ctice. A productivity of 3.5 thm/m(3).24 h and a total fuel rate of 43
9 kg/thm were achieved in 1993, The following factors have contributed
to this result : low-slag operation by using acid pellet and high iro
n content sinter, high level of automation, process control using comp
uter technology.