Masters Theses

Author

Qinfang Xiang

Abstract

"A common feature of all red muds is the presence of substantial levels of iron oxide, present either as hematite or a hydrated ferric oxide. The iron oxide is the source of much of the cost of red mud treatment and disposal, and hinders the use of chemical processes for recovering the titania and other constituents. As a result, many proposed red mud treatment schemes feature a preliminary iron-removal step. An approach proposed in this research program is to reduce the ferric iron contents in red mud to magnetite, which is ferromagnetic and can be recovered by low-gradient magnetic separation. Magnetic separation of the magnetite will generate an iron-oxide concentrate which could be used by an iron-ore processor, leaving behind a residue smaller in volume and more easily processed for the recovery of more valuable constituents. This new process uses a "direct reduction" approach, mixing dried mud with several potential reductants, including coal, charcoal, sawdust and bagasse. Several variables which may have a potential impact on this new process such as the type of mud, the temperature, reduction time, and the mud/reducing agent ratio were investigated.

The results indicate that the ferric iron in all three red muds is readily converted to magnetite, even at low temperatures. Sawdust and bagasse are more effective reducing agents than coal or charcoal, especially at lower temperatures. The conversion of ferric iron in red muds to magnetite is highly dependent on the temperature and mud/reducing agents ratio. However, the conversion quickly becomes invariant with time, suggesting that the reduction process might be controlled by the surface reaction"--Abstract, page iii.

Advisor(s)

Schlesinger, Mark E.

Committee Member(s)

Watson, John L.
Fahrenholtz, William

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Metallurgical Engineering

Publisher

University of Missouri--Rolla

Publication Date

Spring 2001

Pagination

x, 54 pages

Note about bibliography

Includes bibliographical references (pages 51-53).

Rights

© 2001 Qinfang Xiang, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Thesis Number

T 7894

Print OCLC #

47235834

Electronic OCLC #

1079366846

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

http://laurel.lso.missouri.edu/record=b4646706~S5

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