A kiln is a thermally insulated chamber, or oven, in which a controlled temperature regime is produced. Uses include the hardening, burning or drying of materials. Kilns are also used for the firing of materials, such as clay and other raw materials, to form ceramics (including pottery, bricks etc.).
The earliest kiln yet discovered dates to around 6000 BC, and was found at the Yarim Tepe site in modern Iraq.
Specific other uses include:
- To dry green lumber so that the lumber can be used immediately
- Drying wood for use as firewood
- Heating wood to the point of pyrolysis to produce charcoal
- For annealing, fusing and deforming glass, or fusing metallic oxide paints to the surface of glass
- For cremation (at high temperature)
- Drying of tobacco leaves
- Drying malted barley for brewing and other fermentations
- Drying hops for brewing (known as a hop kiln or oast house)
- Smelting ore to extract metal
- Heating limestone with clay in the manufacture of Portland cement
- Heating limestone to make quicklime or calcium oxide