Mineralizing agents, fluorine

Although an alcohol instead of water was used in the solvothermal system, a small amount of water was still unavoidably introduced due to the use of 85 wt% of phosphoric acid in water as phosphorus source and boehmite (6-coordinated Al) as A1 source. If a fluoride source was used as mineralization agent, a small amount of water could be introduced by the fluorine source as well. Studies indicate that the small amount of water played an important role in the formation of the structures of aluminophosphates from solvothermal systems.[74]... 

PFA and MFA have an outstanding chemical resistance even at elevated temperatures. They are resistant to strong mineral acids, inorganic bases, and inorganic oxidizing agents and to most of the organic compounds and their mixtures common in the chemical industry. However, they react with fluorine and molten alkali.55... 

Fluorine occurs in large quantities in the minerals fluorspar or fluorite, CaF2 cryolite, Na3AlFg, md fluorapatite, Ca5(P04)3F. It also occurs in small amounts in sea water, teeth, bones, and blood. F2 is such a strong oxidizing agent that it has not been produced by direct chemical oxidation of F ions. The pale yellow gas is prepared by electrolysis of a molten mixture of KF + HF, or KHF2, in a Monel metal cell. This must be done under anhydrous conditions because H2O is more readily oxidized than F. ... 

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