A crucible is a cup-shaped piece of laboratory equipment used to contain chemical compounds when heating them to very high temperatures. The receptacle is usually made of porcelain or an inert metal. One of the earliest uses of platinum was to make crucibles. More recently, metals such as nickel and zirconium have been used.

A crucible is also a container in which metals are molten, usually for temperatures above 500°C. These crucibles are usually made of graphite with clay as a binder. These crucibles are very durable and resist temperatures to over 1600°C. A crucible is placed into a furnace and, after the melting, the liquid metal is taken out of the furnace and poured into the mold. Some furnaces (usually electric or induction) have an embedded crucible and are tilted when the metal is poured out.

The term crucible is often used for unrelated activities that are very difficult, but act as a refining or hardening process.

See also

• The Crucible (play) and Crucible Theatre.

External links

• Metal Technology - a manufacturer of crucibles