Method for processing steelmaking dust, method for producing zinc, method for producing iron- and steelmaking raw material, and raw material of iron and steel

Patent metadata

Field	Value
Publication number	US-2019106767-A1
Application number	US-201716097075-A
Country	US
Kind code	A1
Filing date	Apr 11, 2017
Priority date	Apr 28, 2016
Publication date	Apr 11, 2019
Grant date	—

Abstract

[Object] To provide a method for processing steelmaking dust, a method for producing zinc, and a method for producing an iron- and steelmaking raw material, which are more advantageous than the Waelz method in terms of energy and economy.
[Solving Means] A method for processing steelmaking dust according to an embodiment of the present invention includes: adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust; and heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added. A ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust is adjusted to be not less than 1.3 and not more than 1.5.

First claim

1 . A method for processing steelmaking dust, comprising:
adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust; and heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added, without generating melt.

2 . The method for processing steelmaking dust according to claim 1 , wherein
the calcium compound contains at least one of quicklime (CaO), hydrated lime (Ca(OH)2), and calcium carbonate (CaCO3).

3 . The method for processing steelmaking dust according to claim 1 , wherein
the step of adding the calcium compound to the steelmaking dust includes adjusting a ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust to be not less than 1.3 and not more than 1.5.

4 . The method for processing steelmaking dust according to claim 1 , wherein
the step of heating and reducing the steelmaking dust to which the calcium compound has been added includes adjusting a temperature in the furnace to be less than 1200° C.

5 . The method for processing steelmaking dust according to claim 1 , wherein
the step of adding the calcium compound to the steelmaking dust includes further adding a carbon material to the steelmaking dust.

6 . The method for processing steelmaking dust according to claim 1 , wherein
the step of heating and reducing the steelmaking dust to which the calcium compound has been added includes adding reducing gas to an inside of the furnace.

7 . The method for processing steelmaking dust according to claim 1 , wherein
the furnace is a rotary kiln, a rotary hearth, or a shaft furnace.

8 . A method for producing zinc, comprising:
adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust, heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added, without generating melt, and recovering a zinc component therefrom.

9 . The method for producing zinc according to claim 8 , wherein
the step of adding the calcium compound to the steelmaking dust includes adjusting a ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust to be not less than 1.3 and not more than 1.5.

10 . The method for producing zinc according to claim 8 , wherein
the step of heating and reducing the steelmaking dust to which the calcium compound has been added includes adjusting a temperature in the furnace to be less than 1200° C.

11 . A method for producing an iron- and steelmaking raw material, which separates zinc from steelmaking dust to recover zinc as the iron- and steelmaking raw material, the method comprising:
adding a calcium compound containing Ca to steelmaking dust containing zinc, the number of moles of Ca being equivalent to or more than the number of moles of Fe in the steelmaking dust, heating and reducing, in a furnace, the steelmaking dust to which the calcium compound has been added, without generating melt, and separating zinc from the steelmaking dust.

12 . The method for producing an iron- and steelmaking raw material according to claim 11 , wherein
the step of adding the calcium compound to the steelmaking dust includes adjusting a ratio of the number of moles of Ca in the calcium compound to the number of moles of Fe in the steelmaking dust to be not less than 1.3 and not more than 1.5.

13 . The method for producing an iron- and steelmaking raw material according to claim 11 , wherein
the step of heating and reducing the steelmaking dust to which the calcium compound has been added includes adjusting a temperature in the furnace to be less than 1200° C.

14 . A raw material of iron and steel, comprising:
zinc whose amount is not more than 0.1% by weight; and dicalcium ferrite (2CaO.Fe2O3) whose amount (% by weight) is large and iron (II) oxide (FeO) whose amount (% by weight) is small.

Assignees

• Univ Tohoku
• Hoei Shokai Co Ltd

Inventors

• Nagasaka Tetsuya
• Yamaguchi Kazuyoshi
• Mizuno Hitoshi
• Koide Shunsuke

Classifications

• C22B5/12

  by gases · CPC title

• C22B1/24

  Binding; Briquetting {; Granulating} · CPC title

• C22B1/245

  with carbonaceous material for the production of coked agglomerates · CPC title

• C22B19/30

  from metallic residues or scraps · CPC title

• C22B7/001

  Dry processes · CPC title