thumb|250px|Charcoal Kilns, California firing.]] Kilns are thermally insulated chambers, or ovens, in which a controlled temperature regimes are produced. They are used to harden, burn or dry materials. Specific 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 glass' surface · For cremation (at high temperature) · Drying of tobacco leaves · Firing of material, such as clay, to form ceramics · Drying malted barley for brewing · Smelting ore to extract metal Ceramic kilns Kilns are an essential part of the manufacture of all ceramics, which, by definition, require heat treatment, often at high temperature. During this process, chemical and physical reactio