Doctoral Dissertations

Alternative Title

Decomposition of chromium hydroxide to form active chromium oxide

Abstract

"This study was concerned with the sinterability of Cr₂C₃ powders produced by the calcination of a Cr(OH)₃ gel. The decomposition of the gel was investigated by thermogravimetric analysis, X-ray analysis and microscopic examination. Comparison was made between the size of crystallites as determined by X-ray line broadening and the size of aggregated particles as determined by independent means. These lineal measurements were compared to surface area measurements on the calcined powders. The degree of sinterability was judged from the density measurements on Cr₂C₃ pellets fired under air, oxygen and nitrogen atmospheres. Energies of activation of 25 and 20 kilocalories per mole were found for the decomposition process and the crystallite growth process, respectively. The decomposition process can be described as a unimolecular mechanism obeying first-order reaction kinetics. The calcined powders were found to be composed of small hexagonal platelets arranged in loosely packed aggregates. The optimum calcination temperature was determined to be approximately 500⁰C. A maximum sintered density of 4.35 grams per cubic centimeter illustrated the effectiveness of a nitrogen sintering atmosphere"--Abstract, page ii-iii.

Advisor(s)

Moore, Robert E., 1930-2003

Committee Member(s)

Bolon, Albert E., 1939-2006
Crookston, J. A.
Planje, Theodore J., 1919-1980
Roach, D. Vincent
O'Keefe, T. J. (Thomas J.)

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering

Sponsor(s)

A. P. Green Refractories Company

Publisher

University of Missouri--Rolla

Publication Date

1968

Pagination

xi, 102 pages

Note about bibliography

Includes bibliographical references (pages 99-101).

Rights

© 1968 Timothy A. Clancy, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Subject Headings

ChromiumRoasting (Metallurgy)Sintering

Thesis Number

T 2102

Print OCLC #

5995511

Electronic OCLC #

805937983

Download

Share

 
COinS