Study on The Characteristics and Application of Inorganic Solidified Foam for Preventing and Controlling Spontaneous Combustion of Coal

Spontaneous combustion of coal is a hazard frequently encountered in coal mining The most efficient way to prevent, attenuate or intercept spontaneous combustion of coal processes is effectively cutting off air penetration into the coal by using materials of high sealing characteristics against air penetration. Based on these, a high-expansion inorganic solidified foam material was obtained through physical and mechanical foaming method, using the substrate formed by the fly ash and cement and adding some composite additives. The rheological characteristics of inorganic solidified foam fluid were studied experimentally. The fluid penetration and diffusion equation of inorganic solidified foam based on the Magnus formula on traditional permeation grouting theory was put forward. Its effect of plugging air leakage was tested. The results showed that the effect of plugging air leakage of the high expansion inorganic solidified foam is significant in different pressure conditions. The mechanical characteristics of the inorganic solidified foam were experimentally studied and the results showed that it has better compression performance and mechanical properties. The inorganic solidified foam was used to plug the air leakage channels of 1410 fully mechanized caving face to prevent the fire in Huafeng coal mine and the effect was significant, with the concentration of CO maintaining less than 18 ppm. Inorganic solidified foam has the characteristics of plugging reinforcing, filling and so on, thus it provides a new technical mean to prevent spontaneous combustion of coal in coal mine.