Case Studies

Open Pit Gold Project

1. Project Overview

This case study describes the development of an open pit gold project, progressing from geological block model interpretation and Whittle optimization to a geotechnically constrained and operationally realistic pit design.

The work focused on understanding the true economic potential of the deposit and translating it into a mineable design that balances value, safety, and implementability.

3D geological block model used for open pit mine optimization and design

2. Client Challenge

The client required a clear understanding of how much of the gold resource could be economically extracted under realistic mining conditions.

Key challenges included:

Strong grade variability typical of gold deposits
The need to evaluate maximum resource utilization without over-designing the pit
Early alignment between economic optimization and future geotechnical constraints
Avoiding unrealistic pit geometries that could not be safely or practically mined

The objective was not only to identify an optimal pit shell, but to develop a defensible and executable open pit design.

Optimized open pit shell based on economic and geotechnical parameters

3. My Role & Responsibilities

I was responsible for the full technical workflow from economic optimization through to practical mine design and scheduling, including:

Interpretation of the geological block model to support optimization and design decisions
Whittle pit optimization and evaluation of alternative economic scenarios
Selection of an appropriate optimization shell to guide pit development
Integration of geotechnical parameters into a stable and mineable pit geometry
Development of the final open pit design, including benches, ramps, and slope sectors
Preparation of an Interactive Schedule (Deswik IS) to test mining sequence, access logic, and design practicality

The interactive scheduling step was used to validate that the pit design could be mined in a logical, progressive sequence, ensuring alignment between geometry, access development, and operational reality.

Final open pit mine design with haul roads and phase development

4. Design Philosophy: From Shell to Reality

While the Whittle shell defined economic potential, the final pit design was governed by real-world constraints.

Key considerations included:

Geotechnical slope parameters and sector-based slope controls
Bench geometry, ramp placement, and access requirements
Operational practicality and long-term slope stability
Consistency between design assumptions and potential mining methods

The design process focused on converting an optimized economic concept into a safe, stable, and mineable open pit.