Doctoral Dissertations

Abstract

"Reaction chemistry and thermochemistry of magnesia-graphite refractory systems containing antioxidants are presented in the form of five different studies. Thermodynamic data for systems Mg-O, AI-O, Si-O, Mg-AI-O, Mg-Si-O, Mg-O-C, AI-O-C, Si-O-C, Mg-AI-O-C and Mg-Si-O-C are presented in the form of volatility diagrams which provide an efficient way to view systems in which non-condensed phases are of paramount importance, as is the case in magnesia-graphite systems. A review of the current literature on the addition of antioxidants to magnesia-graphite brick is presented. The antioxidants considered include AI-metal, Si-metal, Mg-metal, alloys, Mo-metal, ZrB2, Zr-metal, Ti-metal and SiC. Two mechanisms are presented for the formation of a dense magnesia layer, at the hot face of a refractory lining and both arise from a fairly straightforward thermochemical argument. Thermodynamic calculations based on AI(I) and AI44C3(s) stability provide a reasonable estimate of the prevailing internal oxygen partial pressure gradient. The values presented are much lower than those typically cited in literature. A new technique has been developed which adequately simulates the temperature and partial pressure gradient that linings are subjected to during service. Results for magnesia-graphite-aluminum and magnesium-graphite-silicon brick are presented and related to the wear resistance of these linings"--Abstract, page iv.

Advisor(s)

Moore, Robert E., 1930-2003

Committee Member(s)

Morris, Arthur E., 1935-
Reidmeyer, Mary R.
Robertson, D. G. C.
Caballero, Angel
Schlesinger, Mark E.

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Sponsor(s)

American Iron and Steel Institute. Refractory Collaborative Group

Publisher

University of Missouri--Rolla

Publication Date

Spring 1993

Journal article titles appearing in thesis/dissertation

  • Thermochemistry of Magnesia-Graphite Systems Containing Metallic Aluminum or Silicon Additions
  • REVIEW: Role of Additives in Magnesia-Graphite Brick
  • Estimation of Prevailing Oxygen Partial Pressure in BOF Refractory Linings
  • Effects of a Temperature Gradient on the Location and Stability of Phases in Magnesia-Graphite-Metal Brick

Pagination

xviii, 175 pages

Note about bibliography

Includes bibliographical references.

Rights

© 1993 Jeffrey Douglas Smith, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Subject Headings

ThermochemistryRefractory materialsAntioxidants

Thesis Number

T 6547

Print OCLC #

29297662

Electronic OCLC #

907378543

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