Magnetite-based sintered ore and method of producing same

Patent metadata

Field	Value
Publication number	US-10724115-B2
Application number	US-201715704401-A
Country	US
Kind code	B2
Filing date	Sep 14, 2017
Priority date	Mar 17, 2015
Publication date	Jul 28, 2020
Grant date	Jul 28, 2020

Abstract

This invention relates to magnetite-based sintered iron ore wherein a magnetite ore powder, which is not currently utilized owing to its low reducibility index among iron ore materials serving as a main material in iron-making processes, is improved so as to have a high reducibility index, and to a method of manufacturing the same.

First claim

The invention claimed is:

1. A method of manufacturing a magnetite-based sintered iron ore, comprising:
a) compacting a magnetite ore powder or a magnetite ore powder mixture into a magnetite ore lump using a pressure of 30 to 500 MPa; and
b) sintering the magnetite ore lump prepared in a) at a temperature of 1100° C. or above through microwave irradiation,
wherein the magnetite-based sintered iron ore has a reducibility index at a reduction rate of 0.7%/min or more in a 1000° C. 40% CO-60% N 2 gas atmosphere,
wherein when a pressure of 250 MPa or more to 500 MPa or less is applied to the magnetite ore lump in step a), the heating temperature through microwave irradiation is 1100° C.˜2000° C. in step b),
when a pressure of 62 MPa or more to 250 MPa or less is applied to the magnetite ore lump in step a), the heating temperature through microwave irradiation is 1150° C.˜2000° C. in step b),
when a pressure of 30 MPa or more to 62 MPa or less is applied to the magnetite ore lump in step a), the heating temperature through microwave irradiation is 1200° C.˜2000° C. in step b),
wherein the magnetite ore or the magnetite ore mixture itself is sintered by the steps of a) to b) and used directly as a sintered ore, and
wherein the magnetite ore powder mixture further comprises at least one of a hematite ore, a carbonaceous material, and an additive, in addition to the magnetite ore powder.

2. The method of claim 1 , wherein the magnetite-based sintered iron ore has a maximum compressive strength in a bottom direction of about 1.281 kN or more and a maximum compressive stress of 16.31 MPa or more.

3. The method of claim 2 , wherein the magnetite-based sintered iron ore has a maximum compressive strength in a lateral direction of 0.4011 kN or more.

4. The method of claim 1 , wherein the hematite ore is contained so that an amount of the magnetite ore powder is 60 wt % or more based on a total weight of the magnetite ore powder and the hematite ore.

Assignees

• Univ Korea Res & Bus Found

Inventors

• Lee Joonho
• Oh Joon Seok

Classifications

• Y02P10/134

  by avoiding CO2, e.g. using hydrogen · CPC title

• C22B1/20

  in sintering machines with movable grates · CPC title

• C21B13/006

  Starting from ores containing non ferrous metallic oxides · CPC title

• C22B4/00

  Electrothermal treatment of ores or metallurgical products for obtaining metals or alloys (obtaining iron or steel C21B, C21C) · CPC title

• C22B1/16 Primary

  Sintering; Agglomerating · CPC title