Starter dyke optimisation with Muk3D and GoldSim
Tailings water balance and management
MineBridge Software Inc
The sizing of a starter dam for a Tailings Storage Facility (TSF) involves balancing many competing demands. It should cost as little as possible, be high enough to store tailings until the first raise can be constructed, it must be able to contain water safely, and it must be designed in such a way that the long-term integrity of the higher raises are never compromised, among other things.
In addition to these demands there is the complication of the behaviour of the process plant, and the tailings during commissioning. Variations in slurry density, excess water in the TSF, initial settled density of the tailings, reliability issues, and beach slopes above and below water can all impact the way that the tailings beaches are developed and ultimately impact the ability of the starter dyke to contain the required volume of tailings and water.
The conventional approach to the design of a TSF starter dyke will be to start out looking at the elevation required for the deterministic design parameters, find ways to reduce the size or volume of it as much as possible to reduce cost, and then possibly look at some sensitivity to some of the input parameters.
This paper discusses a stochastic modelling approach for starter dykes that allows for a wide range of options to be simulated quickly, with an envelope of possible results produced. The sensitivity to different parameters can also be examined to understand which design inputs have the biggest impact on the required dyke sizing. By integrating the 3D TSF modelling tool Muk3D with GoldSim, it will be demonstrated how a wide range of scenarios can be evaluated and how that information can be used to make better decisions about selection of design options.