Jiang, J, Li, S & Xiao, C 2017, 'Application of paste backfill technology based on the gravel and unclassified tailings in Axi Gold Mine', in A Wu & R Jewell (eds), Proceedings of the 20th International Seminar on Paste and Thickened Tailings
, University of Science and Technology Beijing, Beijing, pp. 358-362.
The downward tunnel-type mining and subsequent backfill, a mining method which requires a rather high strength, is used in Axi Gold Mine, Xinjiang Province, China. In order to meet the strength requirement of more than 4 MPa after curing for 28 days, the paste filling system based on gravel and unclassified tailings was put forward, with the ratio of cement, tailings and gravel being 1:4:2. In the backfilling system, the unclassified tailings of low mass fraction from concentrating mill is dewatered to a mass fraction of more than 60% through a deep-cone thickener with 18 m in diameter. Meanwhile, the gravel collected from stripping waste rock in an open-pit mine is ground to a particle size of less than 16 mm. The unclassified tailings of high mass fraction, the ground gravel and Portland cement are then measured in accordance with the recommended ratio and mixed thoroughly in a continuous twin-shaft mixer (type: JS3200) to form a paste slurry. Finally, the paste is pumped to the stope with a filling pump (type: HGBS120.15.320). This paste backfill technology, based on gravel and unclassified tailings, has such advantages as high strength, low bleeding rate and outstanding tight-filling ratio, etc., not only ensuring safe underground operations, but also providing a way for tailings disposal. The successful application of this technology in Axi Gold Mine has brought huge economic and environmental benefits.