Fluorspar is the most important source of fluorine. In the manufacture of hydrogen fluoride HF , powdered fluorspar is distilled with concentrated sulfuric acid in a lead or cast-iron apparatus. The hydrogen fluoride is obtained in a fairly anhydrous state by fractional distillation in copper or steel vessels and is stored in steel cylinders. The usual impurities in commercial hydrogen fluoride are sulfurous and sulfuric acids, as well as fluorosilicic acid H 2 SiF 6 , arising from the presence of silica in the fluorspar. Hydrogen fluoride is employed in the preparation of numerous inorganic and organic fluorine compounds of commercial importance—for example, sodium aluminum fluoride Na 3 AlF 6 , used as an electrolyte in the electrolytic smelting of aluminum metal.
9 Foods that Cause Inflammation and 9 Ways to Fight it
9 Foods that Cause Inflammation and 9 Ways to Fight it « Solluna by Kimberly Snyder
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AFFF is usually created by combining foaming agents with fluorinated surfactants. Per- and polyfluoroalkyl substances PFAS are the active ingredient in these fluorinated surfactants. When mixed with water and discharged, the foam forms an aqueous film that quickly cuts off the oxygen to a flame, extinguishes the fire, and stops the fire from relighting. It may not be easy to tell if the foam you have contains PFAS.
This peer review discussion has been closed. I've listed this article for peer review because I've worked hard on fluorine, so I think it can't have its previous quality rank anymore; I believe, it's now worth more than C. But I mustn't decide on my own-- I'm opening a peer review in order to re-rank this Top-importance C like Iron at some point and improve further; I hope to make it a FA at some point; everyone's welcome to check that against A-class my current target and B-class my plan B criteria; I'll be there to point your views and do the further work.