Grafietfurnace

Grafietfurnace is a high-temperature electric furnace in which graphite components form the heating element and reaction chamber. The name combines grafiet, the word for graphite in several Germanic languages, with furnace. Grafietfurnaces are used where high temperatures, chemical inertness, and contamination control are required. Typical operating temperatures range from several hundred to about 3000°C, depending on atmosphere and graphite quality.

Most grafietfurnaces employ a graphite tube or crucible enclosed by graphite heating elements that are electrified to generate heat through resistance. The sample is placed in the graphite chamber and the temperature is controlled by adjusting the current; the assembly is operated under inert gas (argon, nitrogen) or vacuum to prevent oxidation of graphite and sample contamination. Graphite's high-temperature stability and low thermal expansion aid rapid heating and uniform temperatures.

Key uses include pyrolysis and carbonization of carbon-rich materials; preparation steps in materials research; and in graphite furnace atomic absorption spectroscopy (GFAAS) where the graphite furnace provides a highly focused heating source to atomize samples for trace element analysis. Graphite furnaces also appear in specialized industrial processes that require localized heating without metal-induced contamination.

Advantages include fast heating and intense heat localization, chemical inertness to many reagents, and compatibility with small sample sizes. Limitations include wear and impurities in graphite, sensitivity to oxygen leading to rapid degradation, and contamination risk from graphite particles; devices require precise atmosphere control and regular maintenance. Developments focus on graphite quality, sealing methods, and integration with optical or spectroscopic sensing.