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Fluorite mining (the main source of fluorine) was estimated in 2003 to be a $550 million industry, extracting 4.5 million tons per year. [4] Mined fluorite is separated into two main grades, with about equal production of each. Acidspar is at least 97% CaF 2; metspar is much lower purity, 60–85%.
Ceramic grade fluorite (85–95% CaF 2) is used in the manufacture of opalescent glass, enamels, and cooking utensils. The highest grade, "acid grade fluorite" (97% or more CaF 2), accounts for about 95% of fluorite consumption in the US where it is used to make hydrogen fluoride and hydrofluoric acid by reacting the fluorite with sulfuric acid ...
Calcium fluoride in the fluorite state is of significant commercial importance as a fluoride source. [11] Hydrogen fluoride is liberated from the mineral by the action of concentrated sulfuric acid : [ 12 ]
Cerium oxide adopts the fluorite structure, space group Fm3m, #225 containing 8-coordinate Ce 4+ and 4-coordinate O 2−. At high temperatures it releases oxygen to give a non-stoichiometric, anion deficient form that retains the fluorite lattice. [6] This material has the formula CeO (2−x), where 0 < x < 0.28. [7]
The fluorite structure refers to a common motif for compounds with the formula MX 2. [1] [2] The X ions occupy the eight tetrahedral interstitial sites whereas M ions occupy the regular sites of a face-centered cubic (FCC) structure. Many compounds, notably the common mineral fluorite (CaF 2), adopt this structure.
Fluorite production (tonnes) by country Country (or area) Production World 5,500,000 China * 3,000,000 Mexico 936,433 South Africa * 240,000 Russia * 210,000 Spain
Antozonite with calcite from the Margnac Mine, Compreignac, Haute-Vienne, Limousin, France - (6x5.5cm) Fluorite (antozonite) from Wölsendorf, Oberpfalz, Southern Germany Antozonite (historically known as Stinkspat , Stinkfluss , Stinkstein , Stinkspar [ 1 ] and fetid fluorite [ 2 ] ) is a radioactive fluorite variety first found in Wölsendorf ...
Seawater fluoride levels are usually in the range of 0.86 to 1.4 mg/L, and average 1.1 mg/L [8] (milligrams per litre). For comparison, chloride concentration in seawater is about 19 g/L. The low concentration of fluoride reflects the insolubility of the alkaline earth fluorides, e.g., CaF 2. Concentrations in fresh water vary more significantly.