Editing Calcium silicate (section)

===Acid mine drainage remediation===
Calcium silicate, also known as [[slag]], is produced when molten [[iron]] is made from [[iron ore]], [[silicon dioxide]] and [[calcium carbonate]] in a [[blast furnace]]. When this material is processed into a highly refined, re-purposed calcium silicate aggregate, it is used in the remediation of [[acid mine drainage]] (AMD) on active and passive mine sites.<ref name="steel slag">{{cite web|last=Ziemkiewicz|first=Paul|title=The Use of Steel Slag in Acid Mine Drainage Treatment and Control|url=http://wvmdtaskforce.com/proceedings/98/98zie/98zie.htm|website=Wvmdtaskforce.com|access-date=25 April 2011|url-status=dead|archive-url=https://web.archive.org/web/20110720064631/http://wvmdtaskforce.com/proceedings/98/98zie/98zie.htm|archive-date=20 July 2011}}</ref> 
Calcium silicate neutralizes active acidity in AMD systems by removing free hydrogen ions from the bulk solution, thereby increasing [[pH]]. As its silicate anion captures H<sup>+</sup> ions (raising the pH), it forms monosilicic acid (H<sub>4</sub>SiO<sub>4</sub>), a neutral solute. Monosilicic acid remains in the bulk solution to play other important roles in correcting the adverse effects of acidic conditions. As opposed to limestone (a popular remediation material),<ref>{{cite web|last=Skousen|first=Jeff|title=Chemicals|url=http://www.wvu.edu/~agexten/landrec/chemtrt.htm#Chemicals|work=Overview of Acid Mine Drainage Treatment with Chemicals|publisher=West Virginia University Extension Service|access-date=29 March 2011|url-status=dead|archive-url=https://web.archive.org/web/20110524070234/http://www.wvu.edu/~agexten/landrec/chemtrt.htm#Chemicals|archive-date=24 May 2011}}</ref> calcium silicate effectively precipitates heavy metals and does not armor over, prolonging its effectiveness in AMD systems.<ref name="steel slag"/><ref>{{cite journal|last=Hammarstrom|first=Jane M.|author2=Philip L. Sibrell|author3=Harvey E. Belkin|title=Characterization of limestone reacted with acid-mine drainage|journal=Applied Geochemistry|issue=18|pages=1710–1714|url=http://mine-drainage.usgs.gov/pubs/AG_18-1705-1721.pdf|access-date=30 March 2011|archive-date=5 June 2013|archive-url=https://web.archive.org/web/20130605231303/http://mine-drainage.usgs.gov/pubs/AG_18-1705-1721.pdf|url-status=dead}}</ref>