Quality or Quantity? Do You Understand Your Orebody?

The past decade has seen mining costs spiral and in the last two years the commodity prices have been volatile. The mining industry is now, once again, focusing on costs and gone are the days that any ore is good ore or metal at any cost.

The current economic climate has created an environment that is being experienced for the first time by many operational engineering and geology staff. When the commodity prices are high, orebodies are forgiving of additional expenditure than in harder times when every dollar spent has to be justified to ensure that operations are profitable.

This article explores the simple changes that mine planning and production engineers can implement to improve their designs and ultimately improve the bottom line. The worked examples in the article will explore the impact on the bottom line that simple changes can have through practical examples comparing an over-engineered (“Rolls Royce”) design to an optimi zed design and the impact that poor geological information can have on profitability.

While some of these changes seem obvious to those with experience of tougher times, a review of several mines and mine designs within Australia show that understanding of the economics of orebody is lacking by many planning engineers. The designs are “Rolls Royce”, but unsustainable in the lower grade orebodies at the lower commodity price.