磷石膏

磷石膏是人们用磷矿石制造化肥时所形成的副产品。它的主要成分是石膏（CaSO4-2H2O），即硫酸钙二水合物。虽然石膏是建筑业中广泛使用的原材料，但由于磷石膏含有天然存在的铀、钍及其子体同位素镭、氡、钋等，因而具有微弱的放射性，所以一般人们不使用磷石膏，而是将其无限期储存起来^[1]^[2]。

Phosphogypsum stack located near Fort Meade, Florida.

参考文献

^ Ayres, R. U., Holmberg, J., Andersson, B., "Materials and the Global environment: Waste Mining in the 21st Century", MRS Bull. 2001, 26, 477. doi:10.1557/mrs2001.119
^ Tayibi, Hanan; Choura, Mohamed; López, Félix A.; Alguacil, Francisco J.; López-Delgado, Aurora. Environmental Impact and Management of Phosphogypsum. Journal of Environmental Management. 2009, 90: 2377–2386. PMID 19406560. doi:10.1016/j.jenvman.2009.03.007.

[Ayr-1] Ayres, R. U., Holmberg, J., Andersson, B., "Materials and the Global environment: Waste Mining in the 21st Century", MRS Bull. 2001, 26, 477. doi:10.1557/mrs2001.119

[Taylor-2] Tayibi, Hanan; Choura, Mohamed; López, Félix A.; Alguacil, Francisco J.; López-Delgado, Aurora. Environmental Impact and Management of Phosphogypsum. Journal of Environmental Management. 2009, 90: 2377–2386. PMID 19406560. doi:10.1016/j.jenvman.2009.03.007.

[1]

[2]