Editing Lime kiln (section)

== History ==
=== Pre-pottery Neolithic ===

==== In plaster, proto-pottery, and mortar ====
[[File:Çatalhöyük 2008 DSC 0007 (2767648656).jpg|thumb|280x280px|Archaeologist Colleen Morgan at Çatalhöyük ]]
Because it is so readily made by heating limestone, lime must have been known from the earliest times, and all the early civilizations used it in building [[mortar (masonry)|mortars]] and as a stabilizer in mud renders and floors.<ref>Hewlett, P. C. (Ed.) (1998). ''Lea's Chemistry of Cement and Concrete: 4th Ed'', Arnold, {{ISBN|0-340-56589-6}}, Chapter 1</ref> According to finds at 'Ain Ghazal in Jordan, Yiftahel in Israel,<ref>Israel did not exist at the time.</ref> and Abu Hureyra in Syria dating to 7500–6000&nbsp;BCE, the earliest use of lime was mostly as a binder on floors and in plaster for coating walls.<ref name=":02">{{Cite journal |last1=Carran |first1=D. |last2=Hughes |first2=J. |last3=Leslie |first3=A. |last4=Kennedy |first4=C. |date=2012 |title=A Short History of the Use of Lime as a Building Material Beyond Europe and North America |url=https://www.researchgate.net/publication/232950138 |journal=International Journal of Architectural Heritage |volume=6 |issue=2 |pages=117–146 |doi=10.1080/15583058.2010.511694 |s2cid=111165006}}</ref> This use of plaster may in turn have led to the development of proto-pottery, made from lime and ash.<ref name=":02" /> In mortar, the oldest binder was mud.<ref name=":02" /> According to finds at Catal Hüyük in Turkey, mud was soon followed by clay, and then by lime in the 6th millennium&nbsp;BCE.<ref name=":02" />

=== Lime use in agriculture and coal ===
[[File:Lime kilns in Pembrokeshire - Porthclais from the coastal path June 2021 13.jpg|thumb|280px|Lime kilns in Porth Clais, [[Wales]]; 2021]]
Knowledge of its value in [[agriculture]] is also ancient, but agricultural use only became widely possible when the use of coal made it cheap<ref>Platt, Colin (1978). ''Medieval England'', BCA, {{ISBN|0-7100-8815-9}}, pp. 116–7</ref> in the coalfields in the late 13th century, and an account of agricultural use was given in 1523.<ref>Sir Anthony Fitzherbert, ''Boke of Husbandrye'', 1523</ref> The earliest descriptions of lime kilns differ little from those used for small-scale manufacture a century ago.{{Citation needed|date=October 2009}} Because land transportation of minerals like limestone and coal was difficult in the pre-industrial era, they were distributed by sea, and lime was most often manufactured at small coastal ports.{{Citation needed|date=October 2009}} Many preserved kilns are still to be seen on quaysides around the coasts of Britain.

=== Types of kilns ===
[[File:Tamsalu rõngasahi 2021.ogv|thumb|Drone video of ruins of limestone ring kiln at Tamsalu, Estonia 2021]]

Permanent lime kilns fall into two broad categories: "flare kilns" also known as "intermittent" or "periodic" kilns; and "draw kilns" also known as "perpetual" or "running" kilns. In a flare kiln, a bottom layer of coal was built up and the kiln above filled solely with chalk. The fire was alight for several days, and then the entire kiln was emptied of the lime.

In a draw kiln, usually a stone structure, the chalk or limestone was layered with wood, coal or coke and lit. As it burnt through, lime was extracted from the bottom of the kiln, through the draw hole. Further layers of stone and fuel were added to the top.<ref>{{cite web |last=Smith|first=Nicky|title=Pre-industrial Lime Kilns |url=http://www.english-heritage.org.uk/publications/iha-preindustrial-lime-kilns/preindustriallimekilns.pdf |work=Introductions to Heritage Assets |publisher=[[English Heritage]]|access-date=21 April 2013|date=May 2011}}</ref><ref>{{cite web |last=Siddall|first=Ruth|title=Kiln Architecture and Technology|url=http://www.ucl.ac.uk/~ucfbrxs/limes/Kilns.htm|work=Materials Science|publisher=University College, London|access-date=21 April 2013}}</ref>

=== Early kilns ===
[[File:LDLimeLimekilnOld.jpg|thumb|280x280px|Cross section of typical early kiln]]
The common feature of early kilns was an egg-cup shaped burning chamber, with an air inlet at the base (the "eye"), constructed of brick. Limestone was crushed (often by hand) to fairly uniform {{convert|20|-|60|mm|in|frac=2|abbr=on}} lumps – fine stone was rejected. Successive dome-shaped layers of limestone and wood or coal were built up in the kiln on grate bars across the eye. When loading was complete, the kiln was kindled at the bottom, and the fire gradually spread upwards through the charge. When burnt through, the lime was cooled and raked out through the base. Fine ash dropped out and was rejected with the "riddlings".

Only lump stone could be used, because the charge needed to "breathe" during firing. This also limited the size of kilns and explains why kilns were all much the same size. Above a certain diameter, the half-burned charge would be likely to collapse under its own weight, extinguishing the fire. So kilns always made 25–30 [[tonne]]s of lime in a batch. Typically the kiln took a day to load, three days to fire, two days to cool and a day to unload, so a one-week turnaround was normal. The degree of burning was controlled by trial and error from batch to batch by varying the amount of fuel used. Because there were large temperature differences between the center of the charge and the material close to the wall, a mixture of underburned (i.e. high [[loss on ignition]]), well-burned and dead-burned lime was normally produced. Typical fuel efficiency was low, with 0.5 tonnes or more of coal being used per tonne of finished lime (15 MJ/kg).

=== Industrial scale production ===
Lime production was sometimes carried out on an industrial scale. One example at [[Annery kiln|Annery]] in North [[Devon]], [[England]], near [[Great Torrington]], was made up of three kilns grouped together in an 'L' shape and was situated beside the [[Rolle Canal|Torrington canal]] and the [[River Torridge]] to bring in the limestone and coal, and to transport away the calcined lime in the days before properly [[metal (pavement)|metalled]] roads existed.<ref name="Griffith">Griffith, R. S. Ll. (1971). ''Annery Kiln, Weare Gifford.'' Grenville College project. Supervisor Mr. B. D. Hughes.</ref>

Sets of seven kilns were common. A loading gang and an unloading gang would work the kilns in rotation through the week.

A rarely used kiln was known as a "lazy kiln".<ref name="Hood">Hood, James (1928). ''Kilmarnock Water and Craufurdland'' Kilm Glenf Ramb Soc. Annals. 1919 – 1930. P. 126.</ref>

===Australia===
In the late 19th and early 20th centuries the town of Waratah in [[Gippsland]], [[Victoria (Australia)|Victoria]], [[Australia]] produced a majority of the quicklime used in the city of [[Melbourne]] as well as around other parts of Gippsland. The town, now called [[Walkerville, Victoria|Walkerville]], was set on an isolated part of the Victorian coastline and exported the lime by ship. When this became unprofitable in 1926 the kilns were shut down. The present-day area, though having no town amenities as such, markets itself as a tourist destination. The ruins of the lime kilns can still be seen today.

<gallery class="center" heights="165" widths="200" caption="Lime burning kilns in Australia">
File:Limestone kiln ruins at Walkerville, Victoria, Australia.jpg|alt=Limestone kiln ruin at Walkerville, Victoria, Australia|Limestone kiln ruin at Walkerville, Victoria, Australia
File:Limestone kiln ruins viewed from Limeburners track at Walkerville, Victoria, Australia.jpg|alt=Limestone kiln ruin as seen from bushwalking track, Walkerville, Victoria, Australia|Limestone kiln ruin as seen from bushwalking track, Walkerville, Victoria, Australia
</gallery>

A lime kiln also existed in [[Wool Bay, South Australia|Wool Bay]], [[South Australia]].
<gallery caption="Lime kiln, Wool Bay" class=center heights=155 widths=200>
File:Wool Bay lime Kiln.JPG|alt=Limestone kiln ruin at Wool Bay, South Australia
</gallery>

===Ukraine===
<gallery class=center heights=165 widths=200>
File:Lime kilns in Manzhykiv Kut, Ukraine — Вапняні печі у Манжиковому Куті 08.jpg|Old lime kilns in Manzhykiv Kut, Ukraine
File:Lime kilns in Manzhykiv Kut, Ukraine — Вапняні печі у Манжиковому Куті 16.jpg|Old lime kilns in Manzhykiv Kut, Ukraine
File:Lime kilns in Manzhykiv Kut, Ukraine — Вапняні печі у Манжиковому Куті 15.jpg|Old lime kilns in Manzhykiv Kut, Ukraine
File:Lime kilns in Manzhykiv Kut, Ukraine — Вапняні печі у Манжиковому Куті 13.jpg|Old lime kilns in Manzhykiv Kut, Ukraine
</gallery>

===United Kingdom===
The large kiln at Crindledykes near [[Haydon Bridge]], Northumbria, was one of more than 300 in the county. It was unique to the area in having four draw arches to a single pot. As production was cut back, the two side arches were blocked up, but were restored in 1989 by [[English Heritage]].

The development of the national rail network made the local small-scale kilns increasingly unprofitable, and they gradually died out through the 19th century. They were replaced by larger industrial plants. At the same time, new uses for lime in the [[chemical industry|chemical]], [[steel]] and [[sugar]] industries led to large-scale plants. These also saw the development of more efficient kilns.

A lime kiln erected at [[Dudley]], [[West Midlands (county)|West Midlands]] (formerly [[Worcestershire]]) in 1842 survives as part of the [[Black Country Living Museum]] which opened in 1976, although the kilns were last used during the 1920s. It is now among the last in a region which was dominated by coalmining and limestone mining for generations until the 1960s.<ref>{{cite web|url=http://www.bclm.co.uk/map18.htm|title=The Limekilns - Black Country Living Museum|website=www.bclm.co.uk|access-date=6 April 2018}}</ref>
<gallery class="center" heights="165" widths="200" caption="Limeburning kilns in Great Britain">
Image:LimeKilnFroghall.JPG|alt=19th century limekilns at Froghall|19th century limekilns at [[Froghall]]
Image:Lime Kiln 1.jpg|alt=A preserved lime kiln in Burgess Park, London|A preserved lime kiln in [[Burgess Park]], London
File:Forrabury and Minster - old lime kiln, Boscastle - geograph.org.uk - 842707.jpg|alt=Old lime kiln, Boscastle, Cornwall|Old lime kiln, Boscastle, Cornwall
Image:Broadstone limekiln stonework detail.JPG|alt=A large limekiln at Broadstone, Beith, Ayrshire.|A large limekiln at Broadstone, Beith, Ayrshire
Image:Annery Kiln, Weare Gifford 1.jpg|The [[Annery kiln]] in Devon, England
Image:Limekiln Crindledykes 1992.jpg|alt=Large 19th-century single limekiln at Crindledykes near Housesteads Northumbria|Large 19th-century single limekiln at Crindledykes near [[Housesteads]] [[Northumbria]]
Image:Dumbarton castle and lime kiln.jpg|alt=Dumbarton castle in 1800 and functioning lime kiln with smoke in the foreground.|Dumbarton castle in 1800 and functioning lime kiln with smoke in the foreground<ref name="Stoddart">Stoddart, John (1800), ''Remarks on Local Scenery and Manners in Scotland.'' Pub. Wiliam Miller, London. Facing p. 212.</ref>
</gallery>

===Other countries===
<gallery class="center" heights="165" widths="200">
File:Antoing JPG04.jpg|Old lime kilns, [[Antoing]], Belgium
File:FornosdaCal1.jpg|[[Lime kilns, Oeiras, Portugal]]
File:Kalkofen Untermarchtal, Baden-Württemberg.jpg|Lime kiln Untermarchtal, [[Baden-Württemberg]]
File:Old lime kiln of 1906 at Simplon, Namibia (2017).jpg|Lime kiln from 1906 at Simplon, [[Namibia]]
File:Lime Kilns - Vojtěšská huť Koněv - in Kladno.jpg|Lime Kilns in Kladno, Czechia, operable until 1975.
</gallery>