Reduced iron production method

Patent metadata

Field	Value
Publication number	US-2020291494-A1
Application number	US-201716301272-A
Country	US
Kind code	A1
Filing date	May 12, 2017
Priority date	May 20, 2016
Publication date	Sep 17, 2020
Grant date	—

Abstract

Disclosed herein is a reduced iron production method enabling heat to be input well into reduced-iron raw materials on a hearth covering material in a reduction-melting furnace to improve the efficiency of treatment thereof. The reduced-iron raw materials are set on the hearth covering material through their falls and reduced on the hearth covering material. The hearth covering material is constituted by carbon materials each having a particle diameter of 5 mm or less. At least 7 mass % of the carbon materials have respective particle diameters each being 0.1 mm or less. This restrains the reduced-iron raw materials from embedment into the hearth covering material.

First claim

1 . A method for producing reduced iron, the method comprising:
a raw material charging step of successively charging a plurality of reduced-iron raw materials each containing a carbonaceous reducing agent and an iron oxide into a reduction-melting furnace having a hearth that travels in a specific direction and a hearth covering material formed of powder laid on the hearth and letting the reduced-iron raw materials fall onto the hearth covering material to set the reduced-iron raw materials on the hearth covering material; and a reduced iron discharging step of successively reducing each of the reduced-iron raw materials on the hearth covering material along with travel of the hearth to thereby produce reduced iron and discharging the reduced iron produced to outside of the reduction-melting furnace, wherein: the hearth covering material is constituted by carbon materials each having a particle diameter of 5 mm or less; and at least 7 mass % of the carbon materials have respective particle diameters each being 0.1 mm or less.

2 . The reduced iron production method according to claim 1 , wherein the reduced-iron raw materials are spherical, and the raw material charging step includes ejecting the reduced-iron raw materials downward from a lower surface of a ceiling located above the hearth and letting the reduced-iron raw materials fall onto the hearth covering material while giving a horizontal velocity, which is in the same direction as a travel direction of the hearth and greater than a moving speed of the hearth, to the reduced-iron raw materials to thereby roll the reduced-iron raw materials on the hearth covering material in a direction of the horizontal velocity.

Assignees

• Kobe Steel Ltd

Inventors

• Hatakeyama Taiji
• O Shorin
• Hotta Masahiro

Classifications

• C21B13/004

  in a continuous way by reduction from ores · CPC title

• C21B13/105 Primary

  Rotary hearth-type furnaces · CPC title