Overview

Mercury is a liquid metal of steel-gray color, primarily extracted from cinnabar and classified as one of the rare earth metals. Mercury and its compounds are widely used in various industries — from metallurgy to medical device manufacturing.

Chemistry and Metallurgy

Originally, mercury was used primarily in metallurgy. Mercury dissolves a number of other metals, forming amalgams. Mercury compounds have been widely used in gilding the domes of Christian churches.

Modern metallurgical applications include:

• Lithography, electroforming, and engraving
• Gold separation from ore in mining operations
• Jewelry production
• Manufacturing of mirrors for industrial and domestic use
• Production of mercury-vapor turbines, vacuum installations, and diffusion pumps

In the chemical industry, mercury is most commonly used in chlorine production as a cathode in the electrolytic process, producing caustic sodium and chlorine. It is also used for temperature control of petroleum during refining.

Energy and Instrumentation

Mercury finds maximum demand in nuclear energy — for thermochemical separation of water into oxygen and hydrogen, as well as for dissolving uranium blocks after their service life. In other types of energy devices, mercury is used in batteries and control instruments.

Instrumentation is the most diverse field of liquid metal application, including:

• Quartz and fluorescent daylight lamps
• Mercury couplings for motors of household appliances
• Manometers, polarographs, barometers, and thermometers
• Various control and measuring instruments

Medicine and Agriculture

In medicine, mercury compounds have historically been used in antiseptics, disinfectants, and diuretics, though modern medicine has largely replaced mercury-based preparations with safer alternatives. Mercury amalgam continues to be used in dentistry for dental fillings.

In agriculture, organic mercury compounds were previously used as fungicides and seed treatments, though these applications have been significantly restricted due to environmental and health concerns.

Electrical Engineering

Mercury is used in the production of mercury switches, mercury-arc rectifiers, fluorescent lighting, and high-intensity discharge lamps. All mercury-containing devices are subject to processing and disposal at specialized enterprises after their operational life.