NATRIUM-ALUMINIUM-FLUORID-PHOSPHATE SOWIE VERFAHREN ZU DEREN HERSTELLUNG.

摘要

New cpds. have formula (I) Nax(AlFy)(PO4)2(OH) (3+x-y-3z) (I) x = no. 2-10; y = 1.1-2.5; z = 1 to (1 + 1/3 x + 1/3y) and exhibit, in the sequence of decreasing intensity, the following X-ray diffraction lines (Guinier-powder absorption) at d (Angstrom) 2.62; 3.74 ; 2.67; 1.87 ; 1.52. Pref. (I) can also contain Ca, Mg or Fe as cations, in an amt. of up to 10 wt.% of the total cation content. (I) are prepd. by: (a) neutralising a phosphoric acid contg. Al and fluoride with NaOH soln., up to pH 6-10, to ppte. the salt; or (b) introducing Al- and F ions into an Na phosphate soln. having Na : P molar ratio 1.5-2.5 ; or (c) heating a stoichiometric mixt. of Na phosphates, AlF3 and Al(OH)3 up to over the m.pt., e.g. to 700-1200 deg.C, and cooling the melt shortly afterwards.