A geological principle for the density of thickened tailings

摘要

The strength of thickened tailings, under both static and earthquake loads, depends on its state parameter. The state parameter can be measured by cone penetration test (CPT) soundings within an existing impoundment, but that does not help when designing/planning a new storage facility. In particular, there are currently no known laboratory sample preparation methods that can reliably replicate the depositional environment of silt/sand tailings within a tailings area, including the resulting in situ state. These issues are of particular importance in the design of thickened tailings deposits, where often a steepened beach profile results in tailings storage above the crest of containment structures. For such a facility, reliable prediction of the range of states likely to develop is crucial in estimating the stability of the tailing stack. To provide reference and realistic bounds to the range of states observed in practice in thickened tailings deposits, CPT data from publicly available sources and Golder Associates' project files were collected and analysed to provide an indication of the effects of depositional environment and tailings type on resulting state. This extends previous work by the authors on this topic for conventional tailings.