Paste-like Pumping Backfilling Technique with High Stowing Gradient and Long Distance

Abstract

In order to achieve the maximum recovery of the shallow residual ore resources in Xikuangshan Mine Flash Star Antimony Ltd. in Hunan province of China, on the premise of safe mining, a new paste-like pumping backfilling technique characterized by long-distance pipeline transportation and a high stowing gradient (the ratio of the whole length to the vertical height of the filling pipeline) was studied through the proportion test, pumpability experiment, system process design and reliability analysis of the backfilling system. It is revealed that the optimum proportions (cement: fly-ash: tailings) applied in the stope and mined-out gobs are 1:2:8 and 1:4:15, respectively with mass fractions both being 74%-76% and the rheological property both being paste-like. Furthermore, the backfill pump HBT80/21-220S has been proved to meet the requirements of the backfill industry. The cost of the backfill system is 23.46 yuan per ton, and the remnant ore recovery rate is 60%. In the end, the output value increased by 2.322 billion yuan. The remarkable economic benefits indicate that the application of horizontal sand silos is feasible. As this backfilling technique sets a precedent in China, it can not only enrich the backfilling theories but also provide some constructive guidance for environmental protection and mining in mines with similar conditions.