Ore Grades

Ore grades around the world are generally decreasing. What does that mean for mineral supply and the transition to clean energy?

The United States Geological Survey defines ore as “The naturally occurring material from which a mineral or minerals of economic value can be extracted.” In most cases, ore is rock that is mined and then processed to extract minerals from within the rock.

Ore grade refers to how much of the target mineral is in the ore. Low-grade ores contain a small percentage of the target mineral and high-grade ores contain a larger percentage of it.

Because humans have been mining for thousands of years, and have gotten increasingly efficient at it, the best and easiest-to-find deposits around the world have already been mined. The general trend globally is that economically viable mineral deposits are lower grade, harder to find and harder to access (i.e. more remote or deeper underground).

Consider apple picking. You start by taking the nicest-looking apples that are within easy reach. As those are taken, you start reaching higher or accepting the occasional bruise on the apples. Eventually you end up climbing the tree or using a ladder to reach the apples that are otherwise out of reach, even if some of them are lower quality than the apples you picked at first.

That is the trend mining is on.

For example, the average ore grade for copper was about 2% in 1900. Today, miners use ore grades of 0.5% copper, a quarter the concentration of a century ago.

Modern science and technology make mining lower grade ore possible and profitable, while also taking proper care of the environment. Historical miners simply did not have the technology to extract at the low grades that are common today.

However, mining and processing lower grade ores is more expensive because more rock has to be extracted and milled. It also increases the amount of water and energy used, and the quantity of tailings generated. These additional costs and operational challenges ultimately add to the prices of products we all use every day.

While lower ore grades are increasingly a challenge, we also need huge new quantities of minerals for things like electric vehicles, solar panels and wind turbines. Copper is an example. According to the World Bank, in the last 5000 years, about 550 million tons of copper have been produced. The world will need to produce about the same amount of copper in the next 25 years to meet global demand (https://www.worldbank.org/en/news/infographic/2019/02/26/climate-smart-m...).

That is an extraordinary challenge and supply shortages for copper and many other minerals are predicted.

Lower ore grades and huge new demands for minerals are just two of the many challenges the global mining industry faces as it works to provide the raw materials needed for clean energy, and everything else in our daily lives.

This is why it is so important that governments actively support their mining industries.