Mine Development Sequencing

The client, a major iron ore producer, engaged Optika to undertake a rapid value based review using Akumen on their existing and planned mines to determine the impact of various development sequences. The primary objective was to use Akumen to assess the choice of mine sequence as prepared internally by the Client, and to provide any further insight for future options development.
In the near future the Client’s current suite of mines are planned to drop off in both production and grade. Several new identified greenfields mines had already each individually been reviewed internally at concept level. Each new mine had its own CAPEX, OPEX, Ramp up Profile and Mine Plan.

Time Based 3D Driver Trees within Akumen’s enabled, Optika to calculate the NPV for various development scenarios. Mining scenarios varied in sequence, size, and timing of 1st ore. Existing mine and ramp down profiles were also taken into consideration.

The main Driver tree contained 150 input nodes and 150 calculation nodes. Each tree was replicated over 30 times to represent the time period over the life of asset, creating 3D models containing 9,000 nodes. For the purpose of evaluating different scenarios and sensitivities, the base model was replicated 220 times. With around 2,000,000 data points generated, extensive analysis and reporting was carried out.

Key Drivers Sensitivity Analysis to NPV tested variations in; Sale Price, % Fe content, % Moisture, CAPEX, OPEX, and Discount Rate. Optika determined the relative contribution to NPV of each of the Key Drivers by undertaking sensitivity analysis.

“5 Why” Root Cause Analysis used Akumen’s extensive reporting capabilities to investigate why certain outcomes were occurring. This rapidly enables identification of; raw source data anomalies, and potential value optimization and opportunities, that could not be seen by if the business analyst were using a traditional excel based approach.

Analysis identified potential NPV improvements, including:
– Re-evaluation of significant source data anomalies to be further investigated by client, including but not limited to; resource model values, mine planning equipment utilization rates, and system output levelling.
– Modifying mine sequencing to ensure high value deposits are mined first.
– Varying the methods of mining within mines dependent on strip ratios.
– Trading off CAPEX v Fe Recovery for dewatering.
– Trading off CAPEX v OPEX for major fixed plant.
– Determining under what Key Driver scenarios does one scenario become better than another.
As a result of this work, the client was able to better plan their internal future studies works to focus on key driver areas with the greatest potential impact to NPV.