Red mud-based composite calcium ferrite and preparation method and use thereof

Patent metadata

Field	Value
Publication number	US-11773025-B2
Application number	US-202217964973-A
Country	US
Kind code	B2
Filing date	Oct 13, 2022
Priority date	Oct 19, 2021
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

Provided is a red mud-based composite calcium ferrite and a preparation method and use thereof. The preparation method of the red mud-based composite calcium ferrite includes the following steps: mixing red mud and a calcium source, and roasting an obtained mixture in an oxygen-containing atmosphere to obtain the red mud-based composite calcium ferrite; where the calcium source is selected from the group consisting of lime and calcium carbonate. In the present disclosure, the composite calcium ferrite is prepared using a solid waste red mud, with a greatly reduced cost of raw materials; on the other hand, compared with traditional calcium ferrite, the composite calcium ferrite mainly has phase structures of CaFe 2 O 4 , Ca 2 FeAlO 5 , and Ca 2 Fe 2 O 5 . Therefore, the composite calcium ferrite has a lower melting point, a higher lime dissolution efficiency, and better fluxing and dephosphorization effects during primary smelting and refining of molten steel, and has broad prospects for use in industry.

First claim

What is claimed is:

1 . A preparation method of red mud-based composite calcium ferrite, comprising the following steps:
mixing red mud and a calcium source, and roasting an obtained mixture in an oxygen-containing atmosphere to obtain the red mud-based composite calcium ferrite; wherein the calcium source is selected from the group consisting of lime and calcium carbonate; an amount of the red mud is in a molar content of Fe 2 O 3 , and an amount of the calcium source is in a molar content of CaO; and the Fe 2 O 3 and the CaO have a molar ratio of 1:(0.8-1); the roasting is conducted at 1,000° C. to 1,200° C. for 0.5 h to 2 h; the red mud has greater than 40 wt% of the Fe 2 O 3 and 10 wt% to 15 wt% of the Al 2 O 3 ; the red mud-based composite calcium ferrite comprises 5% to 15% of CaFe 2 O 4 , 5% to 15% of Ca 2 FeAlO 5 , and 70% to 90% of Ca 2 Fe 2 O 5 by mass percent, and has a melting point of 1,050° C. to 1,100° C.

2 . The preparation method according to claim 1 , further comprising pressing the mixture into a mass before the roasting.

3 . The preparation method according to claim 1 , wherein the lime has greater than 80 wt% of available calcium oxide, and the calcium carbonate has greater than 50 wt% of the available calcium oxide.

4 . The preparation method according to claim 1 , wherein the oxygen-containing atmosphere comprises an air atmosphere or an oxygen atmosphere.

5 . Red mud-based composite calcium ferrite prepared by the preparation method according to claim 1 , comprising CaFe 2 O 4 , Ca 2 FeAlO 5 , and Ca 2 Fe 2 O 5 ; wherein the red mud-based composite calcium ferrite comprises 5% to 15% of the CaFe 2 O 4 , 5% to 15% of the Ca 2 FeAlO 5 , and 70% to 90% of the Ca 2 Fe 2 O 5 by mass percent.

Assignees

• Univ Beijing Science & Technology

Inventors

• Zhang Yanling
• Zhao Zheng
• Zhang Weifeng
• Yu Kan
• Zhang Yao

Classifications

• C04B35/2633 Primary

  containing barium, strontium or calcium · CPC title

• C04B35/2683

  Other ferrites containing alkaline earth metals or lead · CPC title

• C04B2235/3208

  Calcium oxide or oxide-forming salts thereof, e.g. lime · CPC title

• C04B2235/3274

  Ferrites · CPC title

• C04B2235/6583

  Oxygen containing atmosphere, e.g. with changing oxygen pressures · CPC title