A kiln is a thermally insulated chamber, a type of oven, that produces temperatures sufficient to complete some process, such as hardening, drying, or chemical changes. Various industries and trades use kilns to harden objects made from clay into pottery, bricks etc. Various industries use rotary kilns for pyroprocessing—to calcinate ores, produce cement, lime, and many other materials.
The earliest known kiln dates to around 6000 BC, and was found at the Yarim Tepe site in modern Iraq.
Other uses include:
A factory (previously manufactory) or manufacturing plant is an industrial site, usually consisting of buildings and machinery, or more commonly a complex having several buildings, where workers manufacture goods or operate machines processing one product into another.
Factories arose with the introduction of machinery during the Industrial Revolution when the capital and space requirements became too great for cottage industry or workshops. Early factories that contained small amounts of machinery, such as one or two spinning mules, and fewer than a dozen workers have been called "glorified workshops.
Most modern factories have large warehouses or warehouse-like facilities that contain heavy equipment used for assembly line production. Large factories tend to be located with access to multiple modes of transportation, with some having rail, highway and water loading and unloading facilities.
Factories may either make discrete products or some type of material continuously produced such as chemicals, pulp and paper or refined oil products. Factories manufacturing chemicals are often called plants and may have most of their equipment, consisting of tanks, pressure vessels, chemical reactors and pumps and piping located outdoors and are operated by personnel in control rooms. Oil refineries are similar to chemical plants in that most equipment is outdoors.