Learn the most common errors mining engineers make when designing pushbacks - from ignoring geological uncertainty and ore grade variability to neglecting long-term mine planning and commodity price trends.
Video transcription
Why Pushback Design Needs a Long-Term Perspective
In the mining industry, the traditional approach to developing a pushback is to do a rough design when you need to move quickly. But most engineers also want to model the new formation coming into the picture.
The problem is that some people fail to align the pushback with the long-term goal of the mine. Every pushback must fit within the overall life-of-mine plan. However, most traditional pushback designs focus on short-term profitability and neglect the long-term implications - such as future mining phases that must come into the plan, or operational bottlenecks that may arise later. You need to integrate the operational perspective of the mine into the pushback design, and that step is often missed.
Accounting for Geological Uncertainty and Ore Grade Variability
Another common error is ignoring geological uncertainty. The variability of the ore grade is often overlooked because the ore is continuous, and many mining engineers tend to assume that whatever they observed in the current pit is what they will encounter in the pushback.
Instead, you need to work collaboratively with other team members - particularly the geologists - to assess whether the ore grade is varying, and if so, how to incorporate that variability into the global optimization.
This also requires input from the processing team: will the ore variation from the pushback be suitable for the plant? Do they need to adjust operational parameters, or can they maintain current settings? There needs to be a cross-departmental conversation so that everyone understands the direction the operation is heading. When you take a long-term view, the benefits become clear.
Incorporating Commodity Price Trends Into Pushback Planning
The final point is commodity and market condition fluctuations. It is important that when considering a pushback, you also look at commodity price trends. Should you model these trends and include them in the plan?
Dynamic mine planning supports this approach, but most traditional mining engineers do not factor in price trends. As a result, after two or three years of working through a pushback, they end up making a decision to start another one. The challenges and difficulties from handling the first pushback then cascade into the second and third phases that follow.