Effect of curing temperature on the mechanical properties and pore structure of cemented backfill materials with waste rock-tailings

Abstract

In order to reduce the cost of deep mining in Guangxi Gaofeng Mine, the feasibility of underground waste rock used for backfill and was analyzed. The tailings and waste rock taken from Gaofeng Mining Industry had been selected for comparative tests, different ratio of waste rock and tailings and curing temperatures were set, the effect of different conditions on the porosity and strength of waste rock and tailings cemented backfill was investigated. Study indicates that the macroscopic mechanical properties of the backfill are the external response of its microstructure, and the change of the microstructure of the backfill is the essential reason for the change of its mechanical properties. when the waste rock-tailings ratio is 6:4 or 7:3, the USC increases with the increase of the curing temperature; while the waste rock-tailings ratio is 8:2 or 9:1, the USC tends to increase and then decrease with the increase of the curing temperature, where 40℃ is the turning point. In deep mines of Gaofeng Mine, ratio of waste rock and tailings of 9:1 is preferred when the temperature is around 40 °C, while ratio of waste rock and tailings of 6:4 is more effective at deeper depths around 50 °C.