Nickel (Ni) - Everyday Uses

Properties and Occurrence

Nickel (Ni), an element with atomic number 28, is a silvery-white, lustrous metal known for its hardness, ductility, and resistance to corrosion. It is one of the transition metals, exhibiting good electrical and thermal conductivity.

Natural Occurrence on Earth

Nickel is found in various geological formations. Approximately 65% of the Earth’s nickel is concentrated in its core, in an alloy with iron. In the Earth’s crust, nickel is present in two primary types of ore deposits: sulfide deposits and laterite deposits.

Sulfide deposits, such as those found in the Sudbury Basin in Canada and Norilsk in Russia, contain nickel primarily as the mineral pentlandite ((Ni,Fe)$_9$S$_8$). These deposits often form from magmatic intrusions. Laterite deposits, which are the result of intense weathering of ultramafic rocks in tropical and subtropical regions, are prevalent in countries like Indonesia, the Philippines, New Caledonia, and Australia. In laterites, nickel is found in minerals like garnierite and limonite.

Extraction and Industrial Processing

The extraction of nickel depends significantly on the type of ore deposit.

Mining and Ore Processing

For sulfide ores, the process typically involves mining, crushing, and grinding the ore, followed by froth flotation to concentrate the nickel-bearing minerals. The concentrate is then roasted and smelted, often in flash furnaces or electric furnaces, to produce a nickel-iron sulfide matte. Further refining of the matte can occur through various methods, including the carbonyl process (used for high-purity nickel) or electrolytic refining, which produces pure nickel cathodes. Large-scale operations of this type are prominent in countries like Canada and Russia.

For laterite ores, two main industrial pathways are utilized. One method involves pyrometallurgical processing, such as the Rotary Kiln-Electric Furnace (RKEF) route, which produces ferronickel or nickel pig iron. This approach is widely used in countries like China and Indonesia. The other method is hydrometallurgical processing, notably High-Pressure Acid Leaching (HPAL), which extracts nickel and cobalt from the ore using sulfuric acid under high temperature and pressure. HPAL plants are increasingly common in Indonesia and the Philippines, processing limonite ores to produce mixed hydroxide precipitate (MHP) or nickel sulfate.

Common Everyday Uses of Nickel

Nickel’s unique properties make it indispensable in numerous applications worldwide.

1. Stainless Steel Production: The primary use of nickel is in the manufacture of stainless steel. Adding nickel to steel significantly improves its corrosion resistance, ductility, and strength, particularly at high and low temperatures. This makes stainless steel ideal for kitchen appliances, medical instruments, cutlery, and architectural elements found in structures globally. For instance, many modern buildings, including the Petronas Towers in Malaysia, incorporate stainless steel in their construction for durability and aesthetics.

2. Rechargeable Batteries: Nickel plays a crucial role in various rechargeable battery technologies. Nickel-metal hydride (NiMH) batteries are used in hybrid electric vehicles, such as the Toyota Prius, and in portable electronic devices. More recently, nickel-rich cathode materials, like Nickel-Manganese-Cobalt (NMC) and Nickel-Cobalt-Aluminum (NCA), are integral components of lithium-ion batteries, powering electric vehicles and advanced consumer electronics across the globe.

3. Coinage: Due to its durability, resistance to corrosion, and appealing appearance, nickel has been used in coinage for centuries. Many nations incorporate nickel or nickel alloys into their currency. Examples include the US five-cent coin (known colloquially as a “nickel”), Canadian coins, and various Euro coin denominations, where it contributes to their longevity and anti-counterfeiting features.

4. Electroplating: Nickel is extensively used for electroplating, a process where a thin layer of nickel is deposited onto a metal object. This coating provides decorative finishes, enhances corrosion resistance, and increases surface hardness. Common applications include household fixtures like faucets and showerheads found in bathrooms and kitchens worldwide, as well as automotive parts such as bumpers and trim.

5. Specialty Alloys (Superalloys): Nickel is a foundational element in many high-performance alloys, particularly superalloys. These alloys are designed for extreme conditions, exhibiting exceptional strength, creep resistance, and corrosion resistance at high temperatures. Such materials are critical in the aerospace industry for jet engine components (e.g., turbine blades), in gas turbines for power generation, and in chemical processing equipment, with major manufacturers located in countries such as the United States, the United Kingdom, and Germany.