Applied technique of the cemented fill with fly ash and fine-sands

Abstract

Traditional stabilization of backfilling material is done by using Portland cement. However, the high price of cement forced mining engineers to seek cheaper binding materials. Fly ash, which is the industrial waste from thermal power plant, possess the potential activity of jellification, and can be used in cemented fill as a partial substitute for cement to reduce the fill cost. Tests were done during the past few years in Xinqiao Pyrite Mine and Phoenix Copper Mine to determine the technology parameters and the suitable content of fly ash. Specimens with different cement/fly/ash tailings (sands) ratios were tested to obtain the strength values of the fill mass based on the analyses of both the chemical composition and physical and mechanical properties of fly ash. The compressive strength of specimens with a ratio of 1:2:8 (cement to fly ash to tailings) can reach 2 MPa after 90 d curing, totally meeting the requirement of artificial pillar and reducing the fill cost by 20%–30%.

Keywords

fly ash / cementing-agent / cemented fill / replacement

References

[1] Hou Kepeng, WANG Su-bin. Commercialization of fly ash application [J]. China Mining Magazine (in Chinese), 1997, (2): 23.

[2] ShenDanshen. Sustainable development of science and technology of fly ash utilization in China [J]. Journal of Building Materials, 1998, 1(2): 170-170(in Chinese)

[3] ZhangYing, ZhangXiaodan. Resource recovery and comprehensive utilization technology of solid waste [J]. Research of Environmental Sciences, 1998, 11(3): 49-49(in Chinese)

[4] JiangLinhua, LinBaoyu, CaiYuebo. Study on hydration properties of cement binders with a large amount of fly ash [J]. Journal of the Chinese Ceramic Society, 1998, 26(6): 695-695(in Chinese)

[5] LiAimei, WangRuheng. Researches on strength and brittleness of fly ash paving of concrete [J]. Journal of Southwest Institute of Technology, 1997, 12(4): 25-25(in Chinese)

[6] DongShujun, HeFengming, YinLianqing. A study on removal of COD from municipal wastewater by fly ash [J]. Journal of North China Electric Power University, 1997, 24(2): 83-83(in Chinese)

[7] WangZhi, LuHao, QianJueshi. Study on the lime shape in the essential system of activated FA with water reducer [J]. Journal of Chongqing Architecture University, 1999, 21(1): 38-38(in Chinese)

[8] Cao Honghon, Kuang Jianxin. A study on the characteristic of the pozzolanic reaction of fly ash with the exciter [J]. Comprehensive Utilizations of Fly Ash (in Chinese), 1997, (2): 28.