Evaluation of the effect of mixing method, sequence and time on the properties of gelfill
9th International Symposium on Mining with Backfill
Kristie Tarr, Graham Swan,
Since 2001, CANMET Mining and Mineral Sciences Laboratory in Sudbury have been involved with Falconbridge Ltd. (now Xstrata Nickel plc) to evaluate trends in the strength development and water retention properties of a novel backfill material for underground mining, termed Gelfill. Between 2004 and 2006, extensive laboratory tests were undertaken in the Sudbury laboratory of CANMET-MMSL under the Deep Mining Research Consortium (DMRC). The paper compares results obtained from samples circulated through a mini-flow loop and mixer. Although many parameters were studied over the last five (5) years, this paper focuses on the investigation of the effect of the mixing method, mixing sequence, mixing time and curing environment on strength development and water retention of Gelfill. It was found that binder should be added as a powder to the mix in the mini-flow loop, and that mixing slurry in the mini-flow loop as opposed to the mixer generally yielded higher strengths. The practical implications of these observations are the subject of an on-going underground trial that will compare laboratory and in situ properties of a regular slurry fill with Gelfill.
Backfill, mixing, gelfill