Mineral Supply

Have you ever read the back of a cereal box? Some types of cereal are fortified with extra minerals, usually iron and calcium. These minerals are important for your health.

Iron is used to make haemoglobin, a protein that transports oxygen around your bloodstream. Not eating enough iron can lead to anaemia, a nutrient deficiency causing fatigue. Meanwhile, calcium supports healthy bones and teeth. Calcium deficiency can lead to bone problems such as rickets, osteoporosis, and osteomalacia.

Worryingly, mineral supplies are becoming depleted. High demand for all kinds of minerals (not just dietary supplements) has put pressure on the mineral supply chain. So, scientists have been working on new strategies to ensure a stable mineral supply in the future.

Minerals: Definition

Let's begin by defining minerals.

Minerals have an ordered internal structure. Their atoms are positioned in geometric patterns, often forming crystals.

There are over 4000 different minerals naturally occurring on Earth.

Figure 1 – A crystal of epidote, a calcium-iron silicate mineral. Source: unsplash.com

Types of Minerals

Minerals are classified into one of three types: fuel, metallic, and non-metallic.

Mineral Supply Chain

What is the mineral supply chain?

Why do we Extract Minerals?

Minerals play an important role in our daily lives. Without minerals, you wouldn't be reading this article!

Mineral supplies are used in a variety of industries, including:

• Nutrition

• Technology

• Construction

• Manufacturing

• Agriculture

• Jewellery

• Medicine and dentistry

The Steps of the Mineral Supply Chain

What are the main steps of the mineral supply chain?

Ensuring Future Mineral Supplies

Now that we've covered what minerals are and how they are used, it's time to look at the problems that they are facing.

High-grade mineral deposits are being depleted.

Despite this, mineral supply demand isn't slowing down. So, it's critical to develop new technologies to find and extract lower-grade mineral deposits. Furthermore, manufactured products should be designed to minimise the amount of raw materials required, and extend the lifetime of mineral use.

Let's look at some new strategies to ensure future mineral supplies.

Improvements in Exploratory Techniques

As technology improves, so do mineral exploratory techniques. One important process is remote sensing.

Remote sensing is an umbrella term for a range of technologies, such as radar, GIS, sonar, and spectral imaging.

Spectral Imaging and Satellites

All objects on Earth absorb or reflect electromagnetic radiation – the amount of which depends on the wavelength. Every object has a unique spectral fingerprint that allows experts to differentiate between different objects.

Specialised sensing satellites beam infrared radiation down to Earth, then analyse how much infrared radiation is reflected. Once the satellite data is processed, it can be used to estimate the locations of mineral deposits.

Figure 2 – Satellite sensing can show potential mineral sites, such as these exposed salt deposits. Source: unsplash.com

Evaluating Remote Sensing

Remote sensing can evaluate large areas for potential deposits without the time and costs of fieldwork. It can also help prioritise which sites to explore first, reducing risks of new mining projects.

It's most suitable for locating high-value commodities like gold and diamonds.

Bioleaching with Acidophilic Bacteria

Bacteria can break down ores to produce an acidic leachate containing copper ions. Once the bacteria have finished, the ions are collected from the solution.

Evaluating Bioleaching

Bioleaching is a cheap and highly efficient mining technique, obtaining extraction yields of over 90%. It doesn't require high temperatures or destructive mining practices. However, it does produce toxic leachate that damages the environment.

Bioleaching is most suitable for low-grade mineral deposits. For higher-grade deposits, it's more feasible to use traditional smelting methods.

Phytomining

Plants absorb mineral ions from the soil through their roots.

How does it work?

• Plants grow in soil that contains low-grade mineral deposits

• As they grow, the plants absorb metal ions through their roots and concentrate them in their cell

• The plants are harvested and burned

• Metal compounds are left behind in the ash

Evaluating Phytomining

Phytomining can obtain metals from very low-grade deposits, reduces the need for destructive mining methods, and reduces the amount of waste rock. However, it's a slow process.

Other Exploratory Techniques

• Gravimetry: measuring variations in Earth's gravitational field indicates different rock types in sediment or near the surface.

• Magnetometry: measuring variations in Earth's magnetic field indicates magnetic materials, or those contrasting to their environment.

• Seismic Surveys: using reflected sound waves to indicate subterranean mineral resources.

• Resistivity Modelling: driving electrodes into the ground and generating a direct current between them can indicate mineralised areas. The further apart the electrodes, the deeper resistivity measurements can be taken.

• Trial Drilling: taking vertical soil samples for direct chemical analysis.

Cradle-to-Cradle Design

Rather than a new mining method, cradle-to-cradle is a variation of the circular economy concept.

Cradle-to-cradle design focuses on imitating the cycle of nature – with no waste.

Technical materials stay in closed-loop cycles, circulating as nutrients for industry.

Biodegradable materials decompose into safe, non-toxic nutrients, and become food for biological cycles.

Cradle-to-cradle is considered to be equivalent to true sustainability. Reusing all products alleviates pressure on resources and reduces the need for further mining and extraction.

The UK Minerals Strategy

Mineral demand is increasing as the world is shifting towards a carbon-free future. By 2040, global demand for electric vehicle batteries is projected to increase by up to 13 times.

To cope with the surge in demand, the UK laid out its first Critical Minerals Strategy in 2022. It follows the ACE Method: acceleration, collaboration, and enhancement.

Accelerating the UK's domestic capacities:

• Maximise domestic mining (where viable for communities and the natural environment)

• Teach skills in mining and minerals

• Use cutting-edge research and technology

• Accelerate the circular economy to alleviate pressure on primary supplies – see cradle-to-cradle above!

Collaborating with international partners:

• Source minerals from around the world

• Encourage worldwide trading and diplomatic relationships

Enhancing international markets:

• Reduce vulnerability to disruption

• Create a level playing field

• Develop functioning, transparent markets

• Make London the global capital of responsible mineral finance

Critical Minerals

The term “critical minerals” was mentioned in the UK's Minerals Strategy. What is it?

Many critical minerals are experiencing supply issues, or are produced in comparatively small volumes.

Uses for four critical minerals are summarised in this table.

Figure 3 – Rechargeable batteries, such as those found in smartphones, contain critical elements such as lithium, nickel, and manganese. Source: unsplash.com

I hope that this article has explained future mineral supplies for you. Remember that high-grade mineral deposits are being depleted, so it's important to find new methods of mining low-grade deposits, or reduce the demand for minerals.

^{1. Department for Business, Energy & Industrial Strategy, Resilience for the Future: The UK’s critical minerals strategy, 2022}

^{2. National Geographic, Minerals and Gems, 2022}

^{3. National Mining Association, Minerals in Typical Computers, 2005}

^{4. Puja Mondal, Mineral Resources: Definition, Types, Use and Exploitation (with statistics and diagram), 2022}