How is calcium carbide produced?
Industrially, calcium carbide is produced in an electric arc furnace from a mixture of lime and coke at a temperature of about 2.200°C (3.990°F). In its pure form it is a colorless crystalline solid with a rock-like structure at room temperature. This is an endothermic reaction requiring 110 calories (460KJ) per mole and high temperatures to drive off the carbon monoxide. The process has not changed since its invention in 1892:
CaO + 3 C → CaC2 + CO
Calcium carbide reacts with water to form acetylene and calcium hydroxide. The high temperatures required for this reaction are not practical to achieve with conventional combustion, so the reaction is carried out in an electric arc furnace with graphite electrodes. It can also be produced by reacting this compound with nitrogen at relatively high temperatures. The calcium carbide product produced generally contains about 80% calcium carbide by weight. The carbide is crushed to produce small pieces ranging from a few millimeters to 50 millimeters. Impurities are concentrated in finer fractions, and the CaC2 content of the product is determined by measuring the amount of acetylene produced by hydrolysis. Take the crude fraction content of 295L/kg and 300L/kg (pressure 101 kPa, temperature 20°C) in the British and German standards as an example. This reaction is an important part of the chemical industrial revolution. In the early 20th century, the large amount of cheap hydroelectric power from Niagara Falls made this reaction possible in the United States. Calcium carbide is also used for the desulfurization of iron.
| Calcium carbide Chemical Properties |
