Proceedings of the 9th South African Young Geotechnical Engineers Conference, 13, 14 & 15 September 2017 – Salt Rock Hotel, Dolphin Coast, Durban, KwaZulu-Natal Upstream Raise Tailings Dams from a Low Risk Appetite Perspective: A Case Study R. van der Westhuizen1, G. Coetzer2 1Golder Associates Africa, Johannesburg, Gauteng,
[email protected] 2Golder Associates Africa, Johannesburg, Gauteng,
[email protected] Abstract This paper explores some controversy that was experienced when dealing with an international investor with an exceptionally risk averse paradigm on the design of an upstream raise tailings storage facility to be constructed in Limpopo, South Africa. The primary points of contention will be briefly discussed, with a single point regarding liquefaction under seismic loading being explored in more detail. Some of the proposed resolutions to the liquefaction concern will be presented and critically discussed, including the option that will most likely be the final resolution. Keywords: upstream raising; liquefaction; mine tailings 1 Introduction The design of a tailings storage facility (TSF) was undertaken for a greenfield development in the Limpopo region of South Africa. The design was conducted according to established norms and standard practice adopted in the South African mining environment, and the TSF was designed as a lined upstream raise facility, implementing a combination of established deposition methodologies consisting of daywall paddocking and spigotting. The foreign investor with a minority stake in the project voiced some concerns they had regarding the design. The investor originated from Japan, and their primary concern was based on the fact that design and implementation of upstream raise TSFs have been banned in Japan since 1982, due to failures of upstream dams in the 1970s (usually leading to liquefaction).