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Journal of Nanomaterials
Volume 2012 (2012), Article ID 628592, 6 pages
http://dx.doi.org/10.1155/2012/628592
Research Article

Mineral Phase and Physical Properties of Red Mud Calcined at Different Temperatures

1College of Civil Engineering, Chongqing University, Chongqing 400044, China
2College of Civil Engineering, Chongqing Vocational Institute of Engineering, Chongqing 400037, China
3Laboratory of New Technology for Construction of Cities in Mountain Area, Chongqing University and Ministry of Education, Chongqing 400045, China

Received 9 August 2012; Revised 20 September 2012; Accepted 24 September 2012

Academic Editor: Ming-Guo Ma

Copyright © 2012 Chuan-sheng Wu and Dong-yan Liu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Different characterizations were carried out on red mud uncalcined and samples calcined in the range of 100°C–1400°C. In the present paper, the phase composition and structural transition of red mud heated from room temperature are indicated by XRD, TG-DTA, and SEM techniques. The mean particle diameter, density, and bond strength of these samples also have been investigated. The results indicate the decomposition of gibbsite into Al2O3 and H2O between 300°C and 550°C and calcite into CaO and CO2 in the interval of 600–800°C. Tricalcium aluminate and gehlenite are formed in the range of 800–900°C. Combined with the SEM images, the results of physical property testing show that the particle size and the strength each has a continuous rise during the heat treatment from 150°C to 1350°C. But the value of density will undergo a little drop before 450°C and then increases to a higher value at the temperature of 1200°C. These obtained results provide an important base for the further studies of comprehensive utilization of red mud.