Calcium carbide

Chemical compound

Calcium Carbide

Chemical formula of calcium carbide

Calcium carbide is a chemical compound with the chemical formula CaC₂. It is a colorless solid at room temperature, although technical-grade samples can be gray or brown. Calcium carbide is primarily used in the production of acetylene and calcium cyanamide.

Production

Calcium carbide is produced industrially in an electric arc furnace from a mixture of lime and coke at approximately 2,200 °C (3,990 °F). This process was discovered by Thomas L. Willson in 1892 and is known as the Willson process.

Applications

Technical-grade calcium carbide

The primary use of calcium carbide is in the production of acetylene gas. When calcium carbide is treated with water, acetylene gas is released:

CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂

This reaction is the basis of the industrial production of acetylene, which is used as a fuel and a chemical building block. Calcium carbide is also used in the manufacture of calcium cyanamide, which is used as a fertilizer and in the production of other chemicals.

Historical Uses

Calcium carbide was once used in carbide lamps, which were widely used in mining and caving. These lamps produce a bright, white light by burning acetylene gas generated from the reaction of calcium carbide with water.

A lit carbide lamp

Safety and Handling

Calcium carbide reacts violently with water, releasing flammable acetylene gas. Therefore, it must be handled with care, stored in a dry environment, and kept away from moisture.

Related pages

• Acetylene
• Calcium cyanamide
• Electric arc furnace
• Carbide lamp