Super High-water Material Ratio and Optimization of Filling Technology in Thin Coal Seam Filling Mining

Abstract

In order to solve the problems such as the occurrence of slurry bleeding and even the impact of non-solidification on the strength of backfill in the field construction of ultra-high water materials, based on this, the optimized material ratio test was carried out, and on the basis of the bleeding rate test and different mixing process tests to improve on-site filling results. The test results show that: when the proportion of gypsum and lime of B material is 4∶1, the compressive strength of super high-water material was the largest; the stirring process had a great influence on the bleeding rate of the material, and reasonable increase of the mixing time of mixing slurry could effectively reduce bleeding rate, which could greatly reduce the amount of additives. The improved material ratio and filling process were applied to the thin coal seam filling mining face of Tianzhuang Coal Mine. The strength of backfill was tested by field sampling and the real-time data of top and floor displacement obtained by monitoring showed that the strength of backfill was higher than that of the laboratory, and the top and floor displacement was only 96 mm, achieving a good filling effect.

Keywords

• bleeding rate
• stirring method
• strength of consolidation
• filling mining
• super high-water material