Lanthanum—the First Element in the Lanthanide Series

Highlights

• Lanthanum is the first element in the lanthanide series.
• It is found abundantly in the Earth’s crust.
• Used in diverse high-tech applications like NiMH batteries and optical lenses.
• Despite being a rare earth metal, lanthanum has distinct characteristics.
• Primarily extracted as a byproduct of rare earth element mining.
• China dominates global production of lanthanum.
• Significant industrial uses include:
  • Improving alloy performance.
  • Enhancing battery technology.
  • Creating high-refractive-index glass.
  • Serving as a catalyst in petroleum refining.

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A recent article via Stanislav Kondrashov (opens in a new tab) examines the unique role of lanthanum—the first element in the lanthanide series—within the group of rare strategic metals. According to the piece, rare earths are too often seen as homogenous blocks, which overlook the distinct characteristics of each element.  In fact, one reason why the Chinese are so advanced is that they not only understand the distinct differences but have also developed nuanced or even differing methods to extract, separate, and process these mission-critical commodities.

Lanthanum, although classified as a rare earth, is noted for its relative abundance and uniform distribution in the Earth’s crust compared to other metals like copper or zinc. It is typically found alongside other rare earth minerals such as monazite, bastnasite, and cerite. Its valuable industrial applications include acting as a reducing agent in metallurgy, promoting the formation of spheroidal graphite, improving oxidation resistance in alloys, and enhancing the performance of compounds like molybdenum. Additionally, lanthanum’s ability to bond with other materials has led to its use in advanced alloys (e.g., cobalt-lanthanum magnets) and in the production of high-refractive-index glass for optical applications.

Pure lanthanum is a silvery-white metal, but when it oxidizes, its surface can develop a yellowish or brownish tint.

Some Background

Lanthanum (opens in a new tab) (atomic number 57) is the first element in the lanthanide series, its name derived from the Greek lanthanein, meaning “to lie hidden.” Discovered in the 19th century as a constituent of cerite, it is classified as a rare earth element despite being relatively abundant in the Earth’s crust.

Lanthanum typically occurs in mineral deposits alongside other rare earth elements, predominantly in ores such as bastnasite, monazite, and cerite. Major deposits of these ores are found in China, India, Brazil, Australia, and other regions where rare earth elements are mined.

Mining Externalities?

Mining Lanthanum has significant negative environmental impacts, primarily due to the large amounts of waste generated, potential for water contamination from toxic chemicals used in processing, soil disruption, habitat destruction, and the release of radioactive elements often associated with rare earth deposits, particularly when not properly managed; leading to concerns about local ecosystems and human health near mining sites. 

Uses of Lanthanum

Lanthanum’s unique chemical and physical properties have led to a broad spectrum of industrial applications. In metallurgy, it serves as a reducing agent and an additive to enhance oxidation resistance and modify the hardness of alloys—such as in cobalt-lanthanum magnetic materials. Its ability to improve alloy performance also benefits processes like the formation of spheroidal graphite in cast irons and the modulation of molybdenum’s properties. Additionally, lanthanum is crucial in the production of high-refractive-index glass used for lenses in cameras, telescopes, and other optical devices. It is also employed in some high-temperature fuel cell cathodes.

As an example, the element is primarily used in the production of nickel-metal hydride (NiMH) rechargeable batteries for hybrid vehicles and portable electronics, as well as in special optical glass for camera lenses due to its high refractive index, and in certain types of lighting like carbon arc lamps used in studio production, where it is often found as a component of the “mischmetal” alloy used in lighter flints; essentially, lanthanum is used in batteries, high-quality optics, and certain lighting applications. 

• Batteries: Primarily in NiMH batteries for electric and hybrid vehicles due to its ability to store large amounts of hydrogen. 
• Optics: Used in high-quality camera and telescope lenses to improve clarity due to its high refractive index. 
• Lighting: Found in carbon arc lamps used in studio lighting and projection as part of a “mischmetal” alloy. 
• Catalysts: Used as a catalyst in petroleum refining processes. 
• Alloying agent: Can be added to steel to enhance its properties

According to the Royal Society of Chemistry (opens in a new tab) Lanthanum metal itself has no commercial applications, but its alloys are highly useful. A lanthanum-nickel alloy is employed to store hydrogen gas for hydrogen-powered vehicles, and lanthanum is also found in the anode of nickel-metal hydride batteries in hybrid cars. Additionally, lanthanum plays a key role in mischmetal alloys (comprising about 20%), which are used in flints for cigarette lighters.

Lanthanum compounds are widely used in carbon lighting to enhance brightness and mimic sunlight in studio and cinema applications. Lanthanum(III) oxide is essential in producing special optical glasses that improve optical properties and alkali resistance, and lanthanum salts serve as catalysts in petroleum refining. The ion La3+ is used as a biological tracer for calcium ions, and radioactive lanthanum has been explored for cancer treatment.

While pure lanthanum metal lacks direct commercial applications, its alloys and compounds are vital in various industries. A lanthanum-nickel alloy is used for hydrogen storage in fuel cell vehicles, and lanthanum enhances nickel metal hydride batteries in hybrid cars. It is also a key constituent—about 20%—of mischmetal, famously used in cigarette lighter flints. Moreover, rare earth compounds of lanthanum improve the brightness and sunlight-like emission spectrum of carbon lighting for studios and cinema projection. Lanthanum(III) oxide enhances specialized glasses’ optical properties and alkali resistance, while lanthanum salts act as catalysts in petroleum refining. Additionally, the La³⁺ ion is a biological tracer for calcium, and radioactive lanthanum has been investigated for cancer treatment.

Mining, Refining, and Production Methods

Lanthanum is not mined as a primary product; instead, it is extracted as a byproduct of rare earth element mining. The ores—typically bastnasite, monazite, or cerite—are obtained using conventional open-pit or underground mining techniques. So what about ore beneficiation?

Once mined, the ores are crushed and ground, then processed using gravity separation, flotation, and magnetic separation techniques. These methods concentrate the rare earth minerals from the bulk ore.

The concentrated ore is subjected to acid (or sometimes alkaline) leaching, dissolving the rare earth elements into solution. Lanthanum is then isolated from other rare earths via solvent extraction or ion exchange chromatography, yielding lanthanum in oxide form (typically La₂O₃).

The final production of lanthanum metal involves metallothermic reduction. In this process, lanthanum oxide is reduced—commonly using calcium metal—at high temperatures in a furnace to produce high-purity lanthanum metal.

These combined methods—from mining and beneficiation to chemical separation and metallothermic reduction—form the standard industrial process for producing lanthanum, enabling its extensive use in advanced technological applications.

The majority of Lanthanum is mined in China. China is the dominant producer of rare earth elements, including Lanthanum, and holds a significant share of the global market for this metal.  The Bayan Obo mine in Inner Mongolia is the primary mine.