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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 ...
Plants vs. Zombies 2 is a free-to-play [1] tower defense game where players defend the left side of the screen from hordes of zombies approaching from the right. [2] The player uses various plants with different abilities to combat these zombies. [3] Some plants attack zombies directly while others are designed to slow them down, allowing the ...
Plants vs. Zombies is a video game franchise developed by PopCap Games, a subsidiary of Electronic Arts (EA). The series follows the affiliates of David "Crazy Dave" Blazing as they use his plants to defend against a zombie invasion, led by Dr. Edgar George Zomboss.
Plants vs. Zombies Adventures, a spin-off and social game, was released for Facebook on May 20, 2011, [154] and closed on October 12, 2014. [155] A mainline sequel named Plants vs. Zombies 2 was released for iOS on August 14, 2013. [156]
The main uses of fluoride, in terms of volume, are in the production of cryolite, Na 3 AlF 6. It is used in aluminium smelting. Formerly, it was mined, but now it is derived from hydrogen fluoride. Fluorite is used on a large scale to separate slag in steel-making. Mined fluorite (CaF 2) is a commodity chemical used in steel-making.
Yttrocerite is a variety of the mineral fluorite with a chemical formula Ca F 2 +(Y,Ce)F 3. It is bluish red with isometric crystals and is named for the yttrium and cerium it contains. It has a Mohs hardness of 4–5. It has been found in Sweden, several states in the United States and Norway.
Hydrogen fluoride is typically produced by the reaction between sulfuric acid and pure grades of the mineral fluorite: [14] CaF 2 + H 2 SO 4 → 2 HF + CaSO 4. About 20% of manufactured HF is a byproduct of fertilizer production, which generates hexafluorosilicic acid. This acid can be degraded to release HF thermally and by hydrolysis: H 2 SiF ...
Fluorite, the primary mineral source of fluorine, which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb fluo meaning ' to flow ' gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its ...