Carbon black

Carbon black is a form of paracrystalline carbon that has a high surface-area-to-volume ratio, albeit lower than that of activated carbon. It is a black powder used as a pigment and reinforcement in rubber products such as tires and is produced by the incomplete combustion of heavy petroleum products. Carbon black is also known as lamp black, furnace black, and thermal black.

History

The production of carbon black dates back to ancient times. The Chinese used it for making ink around 3,500 BC. In the West, it was used for inks and paints in ancient Greece. It was also used in the Middle Ages for the production of inks and dyes.

Production

Carbon black is produced by the controlled incomplete combustion of hydrocarbons, using an array of processes that can vary depending on the specific properties desired. The most common process uses a high-temperature method in the absence of air or with very limited air. The raw material, often furnace oil, is injected into the combustion chamber, where it is ignited. The resulting gas is then quenched to a temperature where the carbon black particles are formed.

Uses

Carbon black is primarily used as a reinforcing filler in tires and other rubber products. In these applications, it contributes to the tensile strength and resistance to wear and abrasion of the rubber. It is also used as a pigment in inks, coatings, and plastics. Carbon black also has uses in protective coatings, where it can provide low-level UV protection for the underlying material.

Health and environmental impacts

Exposure to carbon black can cause respiratory issues, particularly in the case of chronic exposure. The International Agency for Research on Cancer has classified carbon black as a Group 2B carcinogen, which means it is possibly carcinogenic to humans. Carbon black can also have environmental impacts. It can contribute to global warming by absorbing sunlight and heating the atmosphere. It can also have local effects on temperature and precipitation.

See also

• Activated carbon
• Fullerene
• Graphene
• Soot