The importance of rate of rise in life of mine planning of an upstream raised TSF - a case study
Operational aspects and case histories of mine waste storage
Golder Associates Pty Ltd
This paper presents a case study illustrating the importance of rate of rise in the life of mine planning of an upstream raised tailings storage facility (TSF) in Western Australia. To design facilities that will allow upstream raises to be constructed safely and economically, accurate estimates of the beach slope that is likely to form in the field, the rate of rise at which the tailings can be placed, and the dry density that the tailings solids will achieve after deposition (stored density) are desirable. Where operations have been occurring for some time, these three parameters can be very well defined. However, as the operations expand, the rate of rise can influence the expansion, in particular the timing for implementation and the associated costs.
This paper outlines a series of expansions to an existing gold mine and highlights how the rate of rise became the key constraint and ultimately framed the decision making process. A summary of the method adopted to distribute tailings deposition across between six and nine separate tailings cells, whilst maintaining suitable rates of rise, is discussed and the variety of options resulting from various deposition splits are presented. The influence of rate of rise on the cost and timing for each of the options is also presented, resulting in a two-tiered approach to tailings management that depends on the state of approvals for the mine moving forward.