NKK's three large-sized blast furnaces have been shifted to all-coke operation one after another since January, 1980, and operation of the blast furnaces without liquid fuel was completely achieved in April with another tar injection furnaces. Regarding to the Fukuyama Blast Furnace No. 3 (3 223 m3), NKK decided to operate it with increased blast volume and higher blast temperature and, in making efforts to solve operational problems and to achieve improved operation, obtained some important findings. Based on the above information, all the furnaces are continuing smooth operation owing to proper gas distribution control and furnace heat control. According to the calculation based on operational results hitherto obtained, a productivity coefficient of approximately 2.3 t/m3/d is expected on a monthly average value basis.
