Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Sonochemical action and the influence of heat treatment conditions on the preparation of cements of the CaO-Al2O3 binary system

Full text
Author(s):
R. R Lourenço [1] ; C. C. D Exposito [2] ; R. S Angélica [3] ; J. A Rodrigues [4]
Total Authors: 4
Affiliation:
[1] Universidade Federal de S. Carlos. Departamento de Engenharia de Materiais. Grupo de Engenharia de Microestrutura de Materiais
[2] Universidade Federal de S. Carlos. Departamento de Engenharia de Materiais. Grupo de Engenharia de Microestrutura de Materiais
[3] Universidade Federal do Pará. Instituto de Geociências
[4] Universidade Federal de S. Carlos. Departamento de Engenharia de Materiais. Grupo de Engenharia de Microestrutura de Materiais
Total Affiliations: 4
Document type: Journal article
Source: Cerâmica; v. 56, n. 337, p. 28-38, 2010-03-00.
Field of knowledge: Engineering - Materials and Metallurgical Engineering
Abstract

Cements of the CaO-Al2O3 binary system were prepared through a sonochemical process at room temperature followed by heat treatment. The conventional production consists of a reaction in which a stoichiometric mixture of lime and bauxite or alumina is melted or sintered. High temperatures and energy consumption is an inconvenience associated to this type of synthesis. In the sonochemical process, the initial reagents, calcia and alumina, are put in an aqueous suspension under the action an ultrasonic bath during some time. After that, the material is heat treated, after the evaporation of water. Ultrasonic waves can induce changes in the surface morphology of the particles, including size reduction of them. Consequently, the reagent particles become more reactive and this facilitates the final synthesis of the calcium aluminates during the heat treatment. The action of ultrasonic waves and the influence of thermal treatment conditions were studied on two initials molar compositions calcia:alumina of 1:1 and 1:2. Temperatures of 1000, 1200 and 1300 ºC for 1 and 6 h were employed. SEM and X-ray diffraction were used to characterize the obtained materials and the phases were semi-quantified through Rietveld method. In addition, mechanical strength of the products was evaluated through splitting tensile tests. Pastes consisting of cement, alumina and water were prepared using the calcium aluminates prepared through the sonochemical process and commercial cement as reference. (AU)

FAPESP's process: 01/04324-8 - Systemic approach for the development of advanced refractory castables - II
Grantee:Victor Carlos Pandolfelli
Support Opportunities: Research Projects - Thematic Grants