Cobalt

Cobalt compounds have been used for thousands of years to give glazes and ceramics a blue color. They have been found in Egyptian statuettes and Persian necklace beads from the 3rd millennium BC, in glass artifacts in the ruins of Pompeii, and in China during the Tang Dynasty (618–907 AD) as well as later in the blue porcelain of the Ming Dynasty (1368–1644).

In the Middle Ages, miners considered these compounds valuable but cursed silver ores because they smelled like garlic during smelting due to their arsenic content and could not be reduced. These ores were therefore called kobolds, nickel, or wolf’s spit. In 1735, the Swedish chemist Georg Brandt succeeded in isolating the metal. He recognized it as a new element and named it cobalt.

Today, cobalt is primarily used in lithium-ion batteries, especially in electric vehicles, but also in smartphones, laptops, and other electronic devices. About 60 percent of cobalt demand comes from the battery sector. Electric cars are the main driver of increasing cobalt mining.

Cobalt is an important component of the cathode in lithium-ion batteries. The metal provides stability and a high energy density in the batteries, which is crucial for the range of electric vehicles.

Other applications of cobalt include superalloys for engines, gas turbines, and industrial machinery.

In combination with tungsten and carbon, cobalt forms a hard metal (e.g., tungsten carbide-cobalt), which is used in cutting tools, drills, and mining machinery.

Cobalt is also used in permanent magnets (e.g., aluminum-nickel-cobalt and samarium-cobalt magnets), which play an important role in motors, sensors, and wind turbines.

Furthermore, cobalt is used in catalysts, pigments for the production of paints, ceramics, and glass, as well as in very small amounts in medical products such as joint prostheses and dental alloys.

Cobalt ore is usually obtained as a byproduct during the mining of iron, nickel, copper, silver, manganese, zinc, and arsenic ores. The most important cobalt-containing minerals include cobaltite, heterogenite, spherocobaltite, erythrite, carrollite, and skutterudite, although these are relatively rare.
Currently, the largest amounts of cobalt come from the Central African “Copper Belt.”

About three-quarters of the world’s cobalt supply originates from the Democratic Republic of Congo (DRC), where the largest cobalt mines in the world—Tenke Fungurume and Kamoto—are located. The biggest producer of refined cobalt is China, which imports vast quantities of cobalt ore from the DRC.

Other important sources are sulfide deposits in Russia, Canada, and Australia. Recently, laterite ores in tropical regions such as Indonesia, the Philippines, and New Caledonia have gained in importance.

Indonesia is developing into another key country for cobalt mining.

Among the largest companies are the Chinese CMOC Group (China Molybdenum), operator of the Tenke Fungurume mine. The Swiss company Glencore follows in second place, owning the Kamoto and Mutanda mines in the DRC.

Approximately ten percent of cobalt demand is met through recycling.

Depending on the application, replacing cobalt can lead to performance losses or higher costs. In lithium-ion batteries, the world’s leading use of cobalt, the cobalt content is being reduced. In China, cobalt-free lithium iron phosphate batteries hold a significant market share.

Possible substitutes in other applications include barium or strontium ferrites, neodymium-iron-boron alloys, or nickel-iron alloys in magnets. Cerium, iron, lead, manganese, or vanadium are used as cobalt replacements in pigments.

Iron, iron-cobalt-nickel alloys, nickel, ceramic-metal composites (cermets), or ceramics are applied in cutting and wear-resistant materials.

Nickel-based alloys or ceramics replace cobalt in jet engines. In petroleum catalysts, nickel can substitute for cobalt, and titanium-based alloys are an alternative in prosthetics.