Lesson 8.1: Mine Planning

Lesson 8.1: Mine Planning

We are going to talk about mine planning in this lesson, and the focus is on surface mining. However, almost everything that we cover is equally applicable to underground mine planning, even though the examples that I use here are taken from the surface rather than the underground application.

What do we mean by mine planning, and why do we do it. As to the first question, mine planning is a combination of mine design and scheduling of mining activities. The short answer to the second question is: we need to align our mining activities to meet the financial expectations of the company or its investors. We’ll look at both of these in more detail.

Mine planning involves both mine design and scheduling of mining activities.

The goal of mine design is to create a mine that will allow exploitation of the reserve in a safe, economic, and environmentally responsible manner. This design will reflect the unique characteristics of the deposit, anticipated market for the product, and the profit expectations for mine.

Mine scheduling, on the other hand, is concerned with the sequencing of operations and the assignment of equipment and people to ensure that the intended sequencing and production targets are realized. For example, if you dispatch an electric shovel and trucks to remove ore, but the dragline has not yet removed the overburden overlying the ore, you will have a problem… and you will probably be out of a job! Mine planning is performed over many different time horizons. When you are doing your initial feasibility study, you will look at a life-of-mine time frame, which might be 30 years, and as your planning progresses, you will focus more on the first five years; and once the mine is open, you’ll be looking at time frames as short as this shift or the next few shifts. Not only is mine planning an on-going activity, but the planning for the different time horizons is ongoing.

This can be summarized in the following table:

Let’s think about what this table is telling us.

The long-term plan is updated annually, and, basically, we want to know when it will be time to close the mine. We’re also interested to see the projected production levels in future years so that we can assess profitability as well as our ability to meet market demand. We’ll define a medium time horizon, and this will vary by commodity, company, and life of mine; but a typical horizon is three years. We’ll update this quarterly, and this planning will inform equipment purchases and other capital decisions. Our short-term plans will be concerned with detailed mining plans, e.g., where we will mine next and sequencing, how much production we’ll get, detailed equipment, supply, and personnel needs, detailed supply costs, and so on. Our daily planning will look forward over the next few shifts, and establish detailed staffing plans and equipment assignments. In a nutshell, that’s mine planning.

Now, let's add just a bit more detail to this.