Gallium is a distinctive metallic element with unusual properties. It is a soft, silvery-white metal at room temperature. Its remarkably low melting point, approximately 29.76 °C (85.57 °F), allows it to liquefy when held in a person’s hand, becoming a shiny liquid.
Sources and Commercial Availability
Gallium does not occur freely in nature. Instead, it is found in trace amounts in various ores and is primarily obtained as a byproduct of aluminum production from bauxite. Smaller quantities of gallium are also recovered from zinc ores, such as sphalerite, during their refinement. The extraction process typically involves hydrometallurgical techniques, including ion-exchange, to separate gallium from the primary metals.
Despite its industrial importance, gallium is not readily available in large quantities to the general public. For individuals seeking gallium, it can typically be acquired from specialized online retailers that deal in elements, as well as from chemical or educational suppliers. It is commonly sold in small, pure quantities, primarily intended for hobbyist pursuits or for use in educational settings.
Where Gallium is Used
Gallium plays a significant role in advanced technologies, particularly electronics. A major application is in semiconductors, where gallium arsenide (GaAs) is used for components like microwave frequency integrated circuits, high-speed switching circuits, and infrared circuits. GaAs is also a component in light-emitting diodes (LEDs) and laser diodes, contributing to blue and violet light. It is also an important material for high-efficiency solar cells, including those used in space applications.
Beyond gallium arsenide, gallium nitride (GaN) is another compound, forming the basis of blue and white LEDs in modern lighting and digital displays. GaN is also found in power electronics for electric vehicles and renewable energy systems due to its ability to manage higher voltages and frequencies. Additionally, gallium alloys, such as Galinstan (an alloy of gallium, indium, and tin), replace mercury in low-temperature thermometers, leveraging gallium’s wide liquid range. These applications mean gallium is generally found as an integrated component within these devices rather than as a standalone element in everyday products.
Handling and Storage Precautions
When handling gallium, be aware of its unique characteristics. Its low melting point means it can melt from body heat, staining skin with a grayish residue. While elemental gallium has low toxicity, direct ingestion or prolonged skin contact should be avoided. Some gallium compounds, however, can be harmful if inhaled or ingested.
A primary precaution involves gallium’s interaction with other metals, particularly aluminum. Gallium is corrosive to aluminum; it penetrates and disrupts aluminum’s protective oxide layer and internal structure, causing brittleness through liquid metal embrittlement. Therefore, gallium should not contact aluminum objects or containers. For storage, keep it in non-reactive materials like plastic or glass containers at room temperature to prevent accidental melting or unwanted reactions. Avoiding moisture during storage also prevents discoloration.