Investigation of the In Situ Properties of Cemented Paste Backfill
CIM Vancouver 2002
Kim le Roux, William F Bawden, Murray W Grabinsky, Katherine Klein,
Obtaining an undisturbed sample of cemented paste backfill (CPB) is difficult and expensive, consequently, there is reliance in the mining industry on performance data obtained from laboratory prepared samples of CPB. The degree to which these laboratory prepared samples represent the actual in situ condition is not well defined, and, generally, it is not well understood how the CPB placement process influences the material properties. Therefore, there is a need in the industry to understand how the material properties and hence the performance of the laboratory prepared CPB compares with in situ material. This paper reports the findings of an investigation into the in situ properties of CPB at a gold mine in Northern Ontario. A combination of in situ testing and laboratory testing, conducted on undisturbed samples, was used to quantify the in situ properties and performance of the cemented paste backfill. These results were then compared to those of a laboratory based investigation of the same CPB. It is evident from this investigation that the bulk properties of the in-situ CPB are different from those of the laboratory prepared CPB. The most significant observed differences are that the in situ CPB has a higher void ratio and a lower degree of saturation than the laboratory prepared material. The implication of these differences on the stability and performance of the CPB will be explored in this paper.
cemented paste backfill, mine waste, Tailings, Paste