Research on new high-water solidified materials to reinforce coal and eliminate gas outburst
Abstract
As coal and gas outburst is one of the main mine disasters, it is very important to prevent and eliminate the coal and gas outburst. Grouting setting liquid into coal can strengthen the coal seam, increase rigidity coefficient (f), and reduce expansion energy of gas. According to the related experimental procedures of cement paste, experiments on the performance of complex materials that high-water material added with different admixtures were carried out. Results showed that: as the increase of water-cement ratio (W/C), the mobility and setting time were all increased, but compressive strength and rupture strength were declined, furthermore, high-water material showed early strength, which can reach 80% of 14 days compressive strength when it is 7 days. As a rapid setting and early strength cement, Na2SiO3 had the best effects on shortening setting time, when dosage was 3% , the initial setting time and the final setting time were 13min and 21min shorter than blank samples, while the compressive strength increased more than 2 times. As retarder, the initial setting time can extend to 83min when compounding with tartaric acid of dosage of 0.4%. Through the orthogonal experiment the best additive ratio was determined, which was W/C=2, tartaric acid with dosage of 0.2%, Na2SiO3 with dosage of 3%, bentonite with dosage of 12%. Reinforcement simulation experiment showed that, grouting radius of new setting liquid was 250mm when grouting pressure was 60KPa, 7d rupture strength and compressive strength were 5.2MPa and 6.4MPa, and were 37% and 88% higher than ordinary high water material, which was effective for reinforcing coal and eliminating gas outburst.
References
Anon. (2006). Self-consolidation grout. Masonry Construction the World of Masonry. Volume 19, No. 1, pp. 30-34
Cha, J., Li, S.K., Li, J.H. (2010). Study on the durability of super early strength concrete. Journal of Wuhan University of Technology. Volume 32, No. 7, pp. 48-50
Fu, J.H., Chen, Y.P. (2007). The status and control countermeasures of coal and gas outburst in coal mine in China. Journal of Mining and Safety Engineering. Volume 24, No. 3, pp. 1253-259
Feng, G.M., Jia, K.J., Li, F.K. (2011). Research on the control of open backfill mining with ultra high water materials. Journal of China University of Mining and Technology. Volume 40, No. 6, pp. 841-845
Gao, G.F. (2006). Status and related problems of coal gas outburst mechanism. Industrial Safety and Environmental Protection. Volume 32, No. 12, pp. 36-38
Huang, Z.A., Li, Y.F., Zhang, Y.H., Gao, Y.K., Chen, S.G. (2010). New grouting material to reinforce coal and eliminate outburst. Journal of University of Science and Technology Beijing. Volume 32, No. 7, pp. 833-837
Jiang, X.H., Guo, Z.X., Liu Q.Z. (2010). Effect of the amount of admixture of sulphoaluminate cement concrete chloride ion permeability. Twenty-first Century building materials. Volume 2, No. 2, pp. 23-25
Lu, L.C., Chang, J., Ye, Z.M. (2005). Aluminate silicate minerals and synthesis of high performance cement. Journal of silicate. Volume 33, No. 1, pp. 57-62
Qin, B.T., Lu, Y., Yin, S.J., Cao, K. and Wang, M.G. (2013). Prevention and control technique of complex disaster caused by gas and spontaneous combustion for fully-mechanized sublevel caving face in close-distance seams. Journal of Mining & Safety Engineering. Volume 30, No. 2, pp. 311-316
Wu, Q., Zhang, B.Y., Wang, H.Q. (2010). New hydrate-based technique for coal and gas outburst prevention and low-concentration coal mine gas separation. Journal of Heilongjiang Institute of Science and Technology. Volume 20, No. 1, pp. 23-27
Xiao, P.C. (1994). New technology of coal outburst prevention in Shimen. Coal Mine Modernization. Volume 10, No. 4, pp. 24-26
Yan, Z.P. (2006). Study on the microstructure of a soft soil in high water setting material. Rock and soil mechanics. Volume 25, No. 2, pp. 275-278
Yong, Q.L., Liu, Z.D., Sun, X. J. (2005). Theoretical calculation for equilibrium solubilities and compositional coefficient of titanium carbonitrides in Ti-bearing micro alloyed steel. Steel Iron Vanadium Titanium. Volume 26, No. 3, pp. 12-18
Zhu, J.K. (2011). Application of Shimen coal curing technology to prevent coal and gas outburst. Coal Engineering. No. 1, pp. 39-40
Zhang, Y.H., Liang, T.Z., Cui, J.K. (2003). Application Research of high water material in water injection, dust prevention and sealing technology in "Three Soft" coal seam. Journal of China Coal Society. Volume 28, No. 1, pp. 46-49
Zhang, C. (2014). Research on instability mechanism for sealing segment of boreholes and reinforcing dynamic sealing techniques. China University of Mining and Technology. 23p
