Editing Pyrite (section)

===Dust explosions===
Pyrite oxidation is sufficiently [[exothermic]] that underground [[coal mine]]s in high-sulfur coal seams have occasionally had serious problems with [[spontaneous combustion]].<ref>{{cite journal |last1=Deng |first1=Jun |last2=Ma |first2=Xiaofeng |last3=Zhang |first3=Yutao |last4=Li |first4=Yaqing |last5=Zhu |first5=Wenwen |title=Effects of pyrite on the spontaneous combustion of coal |journal=International Journal of Coal Science & Technology |date=December 2015 |volume=2 |issue=4 |pages=306–311 |doi=10.1007/s40789-015-0085-y|doi-access=free |bibcode=2015IJCST...2..306D }}</ref> The solution is the use of buffer blasting and the use of various sealing or cladding agents to [[Hermetic seal|hermetically seal]] the mined-out areas to exclude oxygen.<ref>{{cite journal |last1=Onifade |first1=Moshood |last2=Genc |first2=Bekir |title=A review of spontaneous combustion studies – South African context |journal=International Journal of Mining, Reclamation and Environment |date=17 November 2019 |volume=33 |issue=8 |pages=527–547 |doi=10.1080/17480930.2018.1466402|bibcode=2019IJMRE..33..527O |s2cid=116125498 }}</ref>

In modern coal mines, [[limestone]] dust is sprayed onto the exposed coal surfaces to reduce the hazard of [[dust explosion]]s. This has the secondary benefit of neutralizing the acid released by pyrite oxidation and therefore slowing the oxidation cycle described above, thus reducing the likelihood of spontaneous combustion. In the long term, however, oxidation continues, and the [[hydrated]] [[sulfate]]s formed may exert crystallization pressure that can expand cracks in the rock and lead eventually to [[cave-in|roof fall]].<ref>{{cite journal |doi=10.1016/j.coal.2005.03.013 |title=Colliery and surface hazards through coal-pyrite oxidation (Pennsylvanian Sydney Coalfield, Nova Scotia, Canada) |year=2005 |last1=Zodrow |first1=E |journal=International Journal of Coal Geology |volume=64 |issue=1–2 |pages=145–155|bibcode=2005IJCG...64..145Z }}</ref>