Research and development of foamed gel for controlling the spontaneous combustion of coal in coal mine

摘要

A new kind of compound material foamed gel composed of compound foaming agent (CFA) and high water absorbency gel (HWAG) and formed by physical and mechanical stirring for controlling the spontaneous combustion of coal in coal mine was researched and developed. It makes use of the all-around properties of foam and gel to control the spontaneous combustion of coal in coal mine. The composition, preparation, and controlling mechanisms of foamed gel were analyzed. To optimize the characterizations. of the foamed gel, the optimal CFA concerning foaming ability and mixed ratios of single foaming agents, mass concentration, and salt-resistance performance as well as the optimal HWAG concerning optimal synthesis parameters, Fourier transform infrared spectroscopy, thermogravimetric property, and foam stability were analyzed. Meanwhile, characterizations including microstructure and controlling spontaneous combustion of coal of foamed gel were studied. The results were best when the mass fraction of compound of modification alkyl polyglucoside (APG) and sodium dodecyl sulfate (SDS) is 0.9%, the mixed ratio of APG versus SDS is 4:1, the mass fraction of HWAG is 0.4%, and methylenebis acrylamide concentration, ammonium persulfate concentration, and mass fraction ratio of soluble starch:acrylic acid of HWAG synthesis are 0.05%, 0.5%, and 1:10, respectively. This is the ideal foamed gel. The success preparation of foamed gel and the microstructures differences between CFA and foamed gel are confirmd by the microstructures analysis results of CFA and foamed gel simultaneously. Moreover, foamed gel can effectively seal air leakages, prolong moisturizing time of coal, markedly enhance cooling effect on coal of moisture, and efficaciously reduce the rate of coal oxidation reaction and the heating rate to control the spontaneous combustion of coal in coal mine. (C) 2016 Elsevier Ltd. All rights reserved.