May 17, 2020

What on Earth? The story behind rare earth minerals

Lynas Corporation
Arafura Resources
Avalon Rare
Dale Benton
5 min
What on Earth? The story behind rare earth minerals
Rare earth minerals hold the key to technological devices of today, but what do we know about them? We take a look at what makes rare earth minerals a s...

Rare earth minerals hold the key to technological devices of today, but what do we know about them? We take a look at what makes rare earth minerals a substantial element in the modern world.

Rare earth elements are a collection of elements that are found within the earth's crust. They are essential to many modern technological devices such as computers, electronics, information networks, communications technologies, advanced transport, defence, environmental mitigation, and much more. They are useful due to the fact that they possess particular properties such as luminescence, magnetism and electrochemical properties – properties that help rare earth elements to aid our technology by offering various functionalities. Reduced weights, lowered emissions, reduced energy consumption, better efficiency, miniaturization, improved performance, speed, thermal stability, durability and just about any desirable mechanical or chemical property with which we wish to imbue a device or system can be achieved through rare earth minerals

How are rare earths formed?

Most, if not all rare earths are already formed, except where volcanic processes may create them. It is the weathering of rocks into sediments which are deposited into a range of geological locations and environments that allow us to find rare earths. They are most often found on shorelines, in rivers, alluvial fans and deltas. Erosion works to concentrate dense materials into deposits which are called placers. The source of the erosion determines which rare earth elements will be found concentrated with element bearing minerals like xenotime and monazite.

Where are rare earths found?

Rare earth minerals are found in mines all over the globe. The rates at which they are found are nearly uniform worldwide, though there are a few places where by chance, their concentration seems to be more pronounced. Due to the even global distribution of rare earth elements, it is generally accepted that they were already formed and contained in the rocky objects that formed our planet before those objects gathered together to form the Earth.

How are rare earths used?

The uses of rare earths are usually in the creation of special alloys. These alloys are used to achieve the various functionalities mentioned above as many of the components in delicate computerized circuitry and other sensitive mechanical elements require very specific properties. Hardness, weight, and conductivity are just a few which must be matched to very specific standards.

What are best practices for mining rare earths?

Modern and advanced mining technologies and the regularity constraints that mining companies are restricted by having had a major impact on the best practices of the industry, meaning mining techniques and methods have become more sensitive to environmental concerns. Current “Green” methods of mining must become more common in the industry if it is to remain sustainable and viable in the decades to come. For these reasons, plans to improve the technology in ways that are less damaging to the environment are always being researched.

Efforts to improve the environmental sensitivity of mining processes include:

  • Closing down unregulated or illegal mines
  • Selecting environmentally friendly processes
  • Implementing newly discovered clean mining technologies
  • Cleaning up shut-down mines
  • Reevaluating Cut-off Grades
  • The development of “Green” Mining Tech

The plans described in modern mining regulatory documents cover many of the same problems that are inherent in the mining of other strategic elements and are not necessarily limited to the mining of rare earth minerals.

Which companies make the most profit from rare earths?

Recognising industry leaders in rare earth mining is an important part of how developing and new companies can model their business plans. Major corporations are always looking to their peers to see how each is behaving within the circumstances under which they must operate. Regulatory restrictions, geological peculiarities, environmental concerns, and Geopolitics are just a few of the circumstances that vary from one firm to another.

The top 5 rare earth mining companies are;

1. Lynas Corporation

The Lynas Corporation owns the most valuable deposit of rare earths in existence and it is among the largest mining companies in the business.

2. Molycorp

Formed in 2008 in California, Molycorp has been the world's largest source of rare earth minerals from the middle 1960s to the early 1990s.

3. Arafura Resources

Arafura Resources is responsible for the development of the Nolans rare earths project in Australia – one of the largest rare earth mines in the world.

4. Avalon Rare Metals Inc.

A Toronto-based rare metals firm, Avalon is now developing a number of projects in Canada.

5. Rare Element Resources

Rare Element Resources is listed among the Top 50 companies on the Toronto Venture Exchange in 2010.

The technologies they use

The 17 elements that fall into the category of rare earth minerals must be extracted, concentrated, smelted, and refined. The leading companies tend to use the most advanced methods which include the following;

Benefaction: a machining process used to enrich useful minerals. This uses the flotation method which is usually accompanied by gravity and magnetic separation techniques.

Concentrate decomposition: This technique uses acid alkaline and chlorine to decompose and remove unwanted materials from the desired minerals.

Smelting processes: Two kinds;

  • Hydrometallurgy: a complex industrial process that results in high purity levels but low productivity.
  • Pyrometallurgy: a simpler process with higher productivity but lower purity.

Extraction Technologies;

  • Fractional Stepping: a method that separates minerals by their level of solubility.
  • Solvent Extraction: the method that replaced Ion exchange, solvent extraction extracts elements from an aqueous solution based on their non-miscibility using organic solvents.

Where are their most productive rare earth mines?

At present, China holds about 97% of the global market in rare earth minerals. Unfortunately, the quantities of rare earth elements usually found are not often exploitable to the point of being economically viable for a large operation. A large part of the reason China is able to maintain a near monopoly on the industry is due to the size and power of their country combined with their refusal to adhere to labor or environmental standards. This has given them a huge advantage in production.

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