Editing Calcium carbonate (section)

===Construction===
The main use of calcium carbonate is in the construction industry, either as a building material, or limestone [[Construction aggregate|aggregate]] for road building, as an ingredient of [[cement]], or as the starting material for the preparation of [[slaked lime|builders' lime]] by burning in a [[kiln]]. However, because of weathering mainly caused by [[acid rain]],<ref>{{cite web|title = Effects of Acid Rain|publisher = US Environmental Protection Agency|access-date = 14 March 2015|url = http://www.epa.gov/acidrain/effects/materials.html|archive-date = 2 March 2015|archive-url = https://web.archive.org/web/20150302173739/http://www.epa.gov/acidrain/effects/materials.html|url-status = live}}</ref> calcium carbonate (in limestone form) is no longer used for building purposes on its own, but only as a raw primary substance for building materials.

Calcium carbonate is also used in the purification of [[iron]] from [[iron ore]] in a [[blast furnace]]. The carbonate is [[Calcination|calcined]] ''in situ'' to give [[calcium oxide]], which forms a [[slag]] with various impurities present, and separates from the purified iron.<ref>{{cite web|title = Blast Furnace|publisher = Science Aid|access-date = 30 December 2007|url = http://www.scienceaid.co.uk/chemistry/industrial/blastfurnace.html|archive-url = https://web.archive.org/web/20071217143213/http://www.scienceaid.co.uk/chemistry/industrial/blastfurnace.html|archive-date = 17 December 2007}}</ref>

In the [[oil industry]], calcium carbonate is added to [[drilling fluid]]s as a formation-bridging and filtercake-sealing agent; it is also a weighting material which increases the density of drilling fluids to control the downhole pressure. Calcium carbonate is added to [[swimming pool]]s, as a [[pH]] corrector for maintaining [[alkalinity]] and offsetting the acidic properties of the [[disinfectant]] agent.<ref>{{Cite book|url=https://books.google.com/books?id=8jF-AwAAQBAJ&q=Calcium+carbonate+is+also+mixed+with+putty+in+setting+stained+glass+windows,+and+as+a+resist+to+prevent+glass+from+sticking+to+kiln+shelves+when+firing+glazes+and+paints+at+high+temperature&pg=PT1601|title=Health & Drugs: Disease, Prescription & Medication|last=Sfetcu|first=Nicolae|date=2014-05-02|publisher=Nicolae Sfetcu|language=en}}</ref>

It is also used as a raw material in the [[Sugar refining|refining of sugar]] from [[sugar beet]]; it is calcined in a kiln with [[anthracite]] to produce calcium oxide and carbon dioxide. This burnt lime is then slaked in fresh water to produce a calcium hydroxide [[Suspension (chemistry)|suspension]] for the precipitation of impurities in raw juice during [[carbonatation]].<ref>{{cite book|last1=McGinnis|first1=R. A.|title=Beet-Sugar Technology|publisher=Beet Sugar Development Foundation|page=178|edition=2nd}}</ref>

Calcium carbonate in the form of [[chalk]] has traditionally been a major component of [[blackboard]] chalk. However, modern manufactured chalk is mostly [[gypsum]], hydrated [[calcium sulfate]] {{chem2|CaSO4*2H2O}}. Calcium carbonate is a main source for growing [[biorock]]. Precipitated calcium carbonate (PCC), pre-dispersed in [[slurry]] form, is a common filler material for [[latex gloves]] with the aim of achieving maximum saving in material and production costs.<ref name=precaco3>{{cite web|title=Precipitated Calcium Carbonate uses |url=http://www.aristocratholding.com/calris-5.html |archive-url=https://web.archive.org/web/20140725032803/http://www.aristocratholding.com/calris-5.html |archive-date=25 July 2014}}</ref>

Fine ground calcium carbonate (GCC) is an essential ingredient in the microporous film used in [[diapers]] and some building films, as the pores are nucleated around the calcium carbonate particles during the manufacture of the film by biaxial stretching. GCC and PCC are used as a filler in [[paper]] because they are cheaper than [[wood fiber]]. Printing and writing paper can contain 10–20% calcium carbonate. In North America, calcium carbonate has begun to replace [[Kaolinite|kaolin]] in the production of [[glossy paper]]. Europe has been practicing this as alkaline [[papermaking]] or acid-free papermaking for some decades. PCC used for paper filling and paper coatings is precipitated and prepared in a variety of shapes and sizes having characteristic narrow particle size distributions and equivalent spherical diameters of 0.4 to 3 micrometers.{{citation needed|date=June 2015}}

Calcium carbonate is widely used as an [[Extender (ink)|extender]] in [[paint]]s,<ref name = reade>{{cite web|title = Calcium Carbonate Powder|publisher = Reade Advanced Materials|date = 4 February 2006|access-date = 30 December 2007|url = http://www.reade.com/Products/Minerals_and_Ores/calcium_carbonate.html|archive-url = https://web.archive.org/web/20080222003757/http://www.reade.com/Products/Minerals_and_Ores/calcium_carbonate.html|archive-date = 22 February 2008}}</ref> in particular [[Gloss and matte paint|matte]] [[emulsion paint]] where typically 30% by weight of the paint is either chalk or marble. It is also a popular filler in plastics.<ref name = reade/> Some typical examples include around 15–20% loading of chalk in [[Polyvinyl chloride|unplasticized polyvinyl chloride]] (uPVC) [[Rain gutter|drainpipes]], 5–15% loading of [[stearic acid|stearate]]-coated chalk or marble in uPVC window profile. [[Polyvinyl chloride|PVC]] cables can use calcium carbonate at loadings of up to 70&nbsp;phr (parts per hundred parts of resin) to improve mechanical properties (tensile strength and elongation) and electrical properties (volume resistivity).{{citation needed|date=June 2015}} [[Polypropylene]] compounds are often filled with calcium carbonate to increase rigidity, a requirement that becomes important at high usage temperatures.<ref name= Imerys>{{cite web |url=http://www.imerys-perfmins.com/calcium-carbonate/eu/calcium-carbonate-plastic.htm |title=Calcium carbonate in plastic applications |access-date=1 August 2008 |publisher=Imerys Performance Minerals |archive-url=https://web.archive.org/web/20080804020529/http://www.imerys-perfmins.com/calcium-carbonate/eu/calcium-carbonate-plastic.htm |archive-date=4 August 2008}}</ref> Here the percentage is often 20–40%. It also routinely used as a filler in [[Thermosetting plastic|thermosetting resins]] (sheet and bulk molding compounds)<ref name = Imerys/> and has also been mixed with [[acrylonitrile butadiene styrene|ABS]], and other ingredients, to form some types of compression molded "clay" [[poker chip]]s.<ref>{{Cite web|url=http://www.xintuchemical.com/why-do-calcium-carbonate-play-an-important-part-in-industrial-a-59.html|title=Why do calcium carbonate play an important part in Industrial|website=www.xintuchemical.com|language=en|access-date=2018-10-07|archive-date=7 October 2018|archive-url=https://web.archive.org/web/20181007183653/http://www.xintuchemical.com/why-do-calcium-carbonate-play-an-important-part-in-industrial-a-59.html|url-status=live}}</ref> Precipitated calcium carbonate, made by dropping [[calcium oxide]] into water, is used by itself or with additives as a white paint, known as [[whitewash]]ing.<ref>{{Cite web|url=https://www.dgci.be/18122-11/precipitated_calcium_carbonate_commodity_price|title=precipitated calcium carbonate commodity price|website=www.dgci.be|access-date=2018-10-07|archive-url=https://web.archive.org/web/20181007223232/https://www.dgci.be/18122-11/precipitated_calcium_carbonate_commodity_price|archive-date=7 October 2018}}</ref><ref name="JimohEtAl2017">{{cite journal | url=http://www.scielo.org.za/pdf/sajc/v70/01.pdf | title=Understanding the Precipitated Calcium Carbonate (PCC) Production Mechanism and Its Characteristics in the Liquid–Gas System Using Milk of Lime (MOL) Suspension | author=Jimoh, O.A. | display-authors=et al | journal=South African Journal of Chemistry | year=2017 | volume=70 | pages=1–7 | doi=10.17159/0379-4350/2017/v70a1 | doi-access=free | access-date=7 October 2018 | archive-date=21 September 2018 | archive-url=https://web.archive.org/web/20180921161721/http://www.scielo.org.za/pdf/sajc/v70/01.pdf | url-status=live}}</ref>

Calcium carbonate is added to a wide range of trade and [[do it yourself]] adhesives, sealants, and decorating fillers.<ref name = reade/> Ceramic tile adhesives typically contain 70% to 80% limestone. Decorating crack fillers contain similar levels of marble or dolomite. It is also mixed with putty in setting [[stained glass]] windows, and as a resist to prevent glass from sticking to kiln shelves when firing glazes and paints at high temperature.<ref>{{Cite web|url=https://www.chemicalprocessing.com/experts/environmental-protection/show/533|access-date=2021-02-03|website=www.chemicalprocessing.com | title = Topic: Re: Can our calcium carbonate "waste" be utilized in other industries so we can divert it from landfills? | date = 4 March 2010 | url-status = live|archive-url=https://web.archive.org/web/20170323143544/http://www.chemicalprocessing.com:80/experts/environmental-protection/show/533/ |archive-date=23 March 2017}}</ref><ref>{{Cite web|title=Why do calcium carbonate play an important part in Industry?|url=http://www.xintuchemical.com/why-do-calcium-carbonate-play-an-important-part-in-industrial-a-59.html|access-date=2021-02-03|website=www.xintuchemical.com|archive-date=7 October 2018|archive-url=https://web.archive.org/web/20181007183653/http://www.xintuchemical.com/why-do-calcium-carbonate-play-an-important-part-in-industrial-a-59.html|url-status=live}}</ref><ref>{{Cite web|title=Calcium Carbonates / Calcite/ Limestone. CaCO3 {{!}} Rajasthan Minerals & Chemicals|url=http://www.rmcl.co.in/calcium-carbonates_calcite.html|access-date=2021-02-03|website=www.rmcl.co.in|archive-date=15 April 2021|archive-url=https://web.archive.org/web/20210415090019/http://www.rmcl.co.in/calcium-carbonates_calcite.html}}</ref><ref>{{Cite web|url=http://kamceramics.com/portfolio/calcium-carbonate/|title=Calcium Carbonate|access-date=2021-02-03|website=kamceramics.com|archive-date=15 April 2021|archive-url=https://web.archive.org/web/20210415064720/http://kamceramics.com/portfolio/calcium-carbonate/|url-status=live}}</ref>

In [[ceramic glaze]] applications, calcium carbonate is known as ''whiting'',<ref name = reade/> and is a common ingredient for many glazes in its white powdered form. When a glaze containing this material is fired in a kiln, the whiting acts as a [[Ceramic flux|flux]] material in the glaze. Ground calcium carbonate is an [[abrasive]] (both as scouring powder and as an ingredient of household scouring creams), in particular in its calcite form, which has the relatively low hardness level of 3 on the [[Mohs scale of mineral hardness|Mohs scale]], and will therefore not scratch [[glass]] and most other [[ceramic]]s, [[Vitreous enamel|enamel]], [[bronze]], [[iron]], and [[steel]], and have a moderate effect on softer metals like [[aluminium]] and [[copper]]. A paste made from calcium carbonate and [[deionized water]] can be used to clean [[tarnish]] on [[silver]].<ref name="Make it Shine">{{cite web|title = Ohio Historical Society Blog: Make It Shine|publisher = Ohio Historical Society|url = http://ohiohistory.wordpress.com/2011/06/02/making-it-shine/|access-date = 2 June 2011|archive-url = https://web.archive.org/web/20120323201653/http://ohiohistory.wordpress.com/2011/06/02/making-it-shine/|archive-date = 23 March 2012}}</ref>