A method for the manufacture of crystal water-free iron(II) orthophosphate of the general formula Fe.sub.3(PO.sub.4).sub.2 or crystal water-free iron(II) metal orthophosphate, iron(II) metal pyrophosphate or iron(II) metal metaphosphate of the general formula Fe.sub.aMet.sub.b(PO.sub.c).sub.d, where a is a number from 1 to 5, b is a number from >0 to 5, c is a number from 2.5 to 5, d is a number from 0.5 to 3 and Met represents one or more metals selected from the group consisting of K, Rb, Cs, Mg, Ca, Sr, Ba, the transition metals (d block), in particular Sc, Y, La, Ti, Zr, Hf, Nb, Ta, Cr, Mo, W, Mn, Cu, Zn and the metals and semimetals of the third, fourth and fifth main groups, in particular B, Al, Ga, In, Si, Sn, Sb, Bi and the lanthanoids.

A method for the manufacture of crystal water-free iron(II) orthophosphate of the general formula Fe.sub.3(PO.sub.4).sub.2 or crystal water-free iron(II) metal orthophosphate, iron(II) metal pyrophosphate or iron(II) metal metaphosphate of the general formula Fe.sub.aMet.sub.b(PO.sub.c).sub.d, where a is a number from 1 to 5, b is a number from >0 to 5, c is a number from 2.5 to 5, d is a number from 0.5 to 3 and Met represents one or more metals selected from the group consisting of K, Rb, Cs, Mg, Ca, Sr, Ba, the transition metals (d block), in particular Sc, Y, La, Ti, Zr, Hf, Nb, Ta, Cr, Mo, W, Mn, Cu, Zn and the metals and semimetals of the third, fourth and fifth main groups, in particular B, Al, Ga, In, Si, Sn, Sb, Bi and the lanthanoids.

Provided is a powder containing ferric pyrophosphate that affords high iron absorbability, as a main component of an oral iron preparation. The present invention relates to a composite powder containing ferric pyrophosphate, which is a powder containing ferric pyrophosphate and a sodium component, wherein (1) the content of ferric pyrophosphate is 95 wt % or higher, and (2) a (Fe+Na)/P molar ratio is 0.8 to 1.0.

Provided is a powder containing ferric pyrophosphate that affords high iron absorbability, as a main component of an oral iron preparation. The present invention relates to a composite powder containing ferric pyrophosphate, which is a powder containing ferric pyrophosphate and a sodium component, wherein (1) the content of ferric pyrophosphate is 95 wt % or higher, and (2) a (Fe+Na)/P molar ratio is 0.8 to 1.0.

Polyphosphate compositions are produced by a process that includes the steps of continuously introducing a phosphate compound into a polymerization vessel, polymerizing the phosphate compound at a temperature of 250-450? C. for a time period sufficient to form the polyphosphate composition, and continuously discharging the polyphosphate composition from the polymerization vessel. The phosphate compound can be fed to the polymerization vessel in the form of an aqueous slurry containing 5-50 wt. % of the phosphate compound. Resulting polyphosphate compositions often contain at least 8 wt. % of a polyphosphate and less than 35 wt. % of the phosphate compound.

The invention is related to a flotation process using an improved collector to remove alkaline earth metal carbonate impurities from phosphate ores. The flotation feed may be conditioned with the improved carbonate collector at acidic pH, and subjected to a reverse flotation. The cell overflow may be collected as waste in which carbonate minerals dominate, and the cell underflow may be the phosphate concentrate. The collector may be a combination of chemicals, comprising: (1) any kind of fatty acids, either conventional fatty acid, saponified fatty acid, or modified fatty acid; (2) chemicals with sulfonate or sulfate groups, such as dodecylbenzene sulfonic acid (DDBSA) or its salt, sodium dodecyl sulfate (SDS), sodium lauryl sulfate (SLS), sodium coco sulfate (SCS), etc.; and (3) phosphorous-bearing chemicals, such as sodium tripolyphosphate (STPP), sodium hexametaphosphate (SFMP), trisodium phosphate (TSP), Tetrasodiumpyrophosphate (TSPP), etc. With the improved collector, the separation selectivity and phosphate recovery may be significantly improved.

A method of restoring the proton conductivity of a sintered pyrophosphate membrane of intermediate temperature fuel cells (IT-FCs) by introducing phosphoric acid into the sintered SnP.sub.2O.sub.7 membrane to react with the degraded SnP.sub.2O.sub.7 species and thus restore the membrane pyrophosphate and proton conductivity. Such cells operate with low external humidification, and the active area of the cells may be fabricated up to 100 cm.sup.2 in size.

A method of restoring the proton conductivity of a sintered pyrophosphate membrane of intermediate temperature fuel cells (IT-FCs) by introducing phosphoric acid into the sintered SnP.sub.2O.sub.7 membrane to react with the degraded SnP.sub.2O.sub.7 species and thus restore the membrane pyrophosphate and proton conductivity. Such cells operate with low external humidification, and the active area of the cells may be fabricated up to 100 cm.sup.2 in size.

Dental health care compositions including tin pyrophosphate and methods of producing the same are provided. In an exemplary embodiment, a method of producing tin pyrophosphate includes combining tin tetrafluoroborate with a pyrophosphate salt composition to produce a precipitate, where the precipitate includes tin pyrophosphate and a tetrafluoroborate salt. The tetrafluoroborate salt is then removed from the precipitate.

Dental health care compositions including tin pyrophosphate and methods of producing the same are provided. In an exemplary embodiment, a method of producing tin pyrophosphate includes combining tin tetrafluoroborate with a pyrophosphate salt composition to produce a precipitate, where the precipitate includes tin pyrophosphate and a tetrafluoroborate salt. The tetrafluoroborate salt is then removed from the precipitate.