Nkk Corporation

Nippon Kokan Kabushiki Kaisha

Hideomi Yanaka

Noboru Sakamoto

Yotaro Ohno

Hidetoshi Noda

Akira Kumasaka

A method for manufacturing agglomerates of sintered pellets includes the steps of blending, mixing and pelletizing flux and coarse grain coke with fine iron ore, coating green pellets obtained in the step of the mixing and pelletizing with powdery coke, and sintering the green pellets coated with the powdery coke. The coarse grain coke has a particle size of 1 to 7 mm. 1 to 50 parts of the coarse grain coke, by weight, are added to 100 parts of the total amount of the fine iron ore and the flux by weight.

Method for manufacturing agglomerates of sintered pellets

A method for manufacturing cold bonded pellets comprises the steps of mixing fine iron ore with binder and pelletizing the mixture of the fine iron ore and the binder to manufacture green pellets, charging the green pellets into a travelling grate, a layer of the green pellets which has a predetermined height being formed on the travelling grate, blowing gas containing carbon dioxide into the layer of the green pellets on the travelling grate, the green pellets being cured by the gas containing carbon dioxide, and the gas having passed through the layer of the green pelllets being discharged, and drying the curen green pellets. The gas containing carbon dioxide has a concentration of 55 vol. % carbon dioxide or more. The gas containing carbon dioxide has a concentration of 20 vol. % nitrogen or less. The gas containing carbon dioxide is blown into the green pellets layer at a flow rate of 0.1 to 1.0 Nm.sup.3 /sec. for 1 m.sup.2 of the area of the grate, Nm.sup.3 being the volume of the gas in a normal condition.

Method for manufacturing cold bonded pellets

A method for manufacturing agglomerates of fired pellets comprising the steps of: the first pelletization step of adding and mixing fluxes to fine iron ores containing 30 to 95 wt. % of those of 0.125 mm or less in particle size to form a mixture and to pelletize the mixture into green pellets; the second pelletization step of adding powder cokes containing 80 to 100 wt. % of those of 1 mm or less in particle size to the green pellets, in amount of 2.5 to 4.0 wt. % to the fine iron ores, to prepare, through pelletization, green pellets coated with the powder cokes; and the sintering step of charging the green pellets coated with the powder cokes into a grate type sintering machine to manufacture the agglomerates of fired pellets. And furthermore, in another method for manufacturing agglomerated of fired pellets, fine iron ores containing 10 to 80 wt. % of those of 0.044 mm or less in particle size and powder cokes containing 20 to 70 wt. % of those of 1 mm or less in particle size are used.

Growing community of inventors

Kawasaki, Japan

Hideomi Yanaka