Table of Contents Author Guidelines Submit a Manuscript
Advances in Materials Science and Engineering
Volume 2014 (2014), Article ID 347386, 10 pages
http://dx.doi.org/10.1155/2014/347386
Research Article

Preparation and Stability of Inorganic Solidified Foam for Preventing Coal Fires

1State Key Laboratory of Coal Resources and Mine Safety, CUMT, Xuzhou, Jiangsu 221008, China
2Faculty of Safety Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China

Received 14 March 2014; Revised 21 May 2014; Accepted 26 May 2014; Published 2 July 2014

Academic Editor: Peter Chang

Copyright © 2014 Botao Qin et al. 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

Inorganic solidified foam (ISF) is a novel material for preventing coal fires. This paper presents the preparation process and working principle of main installations. Besides, aqueous foam with expansion ratio of 28 and 30 min drainage rate of 13% was prepared. Stability of foam fluid was studied in terms of stability coefficient, by varying water-slurry ratio, fly ash replacement ratio of cement, and aqueous foam volume alternatively. Light microscope was utilized to analyze the dynamic change of bubble wall of foam fluid and stability principle was proposed. In order to further enhance the stability of ISF, different dosage of calcium fluoroaluminate was added to ISF specimens whose stability coefficient was tested and change of hydration products was detected by scanning electron microscope (SEM). The outcomes indicated that calcium fluoroaluminate could enhance the stability coefficient of ISF and compact hydration products formed in cell wall of ISF; naturally, the stability principle of ISF was proved right. Based on above-mentioned experimental contents, ISF with stability coefficient of 95% and foam expansion ratio of 5 was prepared, which could sufficiently satisfy field process requirements on plugging air leakage and thermal insulation.