Abstract: A cement mix for preparation of a magnesium silico-phosphate cement (MSPC) with an altered hardening rate is provided. The cement mix comprises on the order of 1% of an [MF6]n? salt or acid. Upon addition of water, the mix produces a final set cement that has similar physical properties to those of a cement prepared from a mix lacking the additive, but with a significantly altered setting time. In some embodiments of the invention, the additive is provided in the form of a coating for the MgO component of the mix. In preferred embodiments, H2TiF6, Na2TiF6 and/or K2TiF6 are used as retarders, while K3AlF6 is used as an accelerant. Other embodiments use M?nMF6 compounds wherein M? is an alkali metal, an alkaline earth metal, or H, and M is chosen from inter alia Ti (n=2), Zr (n=2), P (n=1), Al (n=3), and Sb (n=1).

Abstract: A method is provided for advantageously altering the rate of hardening of a magnesium silico-phosphate cement (MSPC). Addition of on the order of 1% of an [MF6]n? salt or acid to an MSPC, obtained by adding the salt or acid either directly to the dry mix or to the water used to effect hydraulic hardening of the cement, significantly alters the hardening rate without adversely affecting the physical properties of the final set cement. In preferred embodiments, Na2TiF6 and/or K2TiF6 are used as retardants, while K3AlF6 is used as an accelerant. Other embodiments use M?n-MF6 compounds wherein M? is an alkali metal, an alkaline earth metal, or H, and M is chosen from inter alia Ti (n=2), Zr (n=2), Si (n=2), P (n=1), Al (n=3), and Sb (n=1).

Abstract: A method is provided for advantageously altering the rate of hardening of a magnesium silico-phosphate cement (MSPC). Addition of on the order of 1% of an [MF6]n? salt or acid to an MSPC, obtained by adding the salt or acid either directly to the dry mix or to the water used to effect hydraulic hardening of the cement, significantly alters the hardening rate without adversely affecting the physical properties of the final set cement. In preferred embodiments, Na2TiF6 and/or K2TiF6 are used as retardants, while K3AlF6 is used as an accelerant. Other embodiments use M?n-MF6 compounds wherein M? is an alkali metal, an alkaline earth metal, or H, and M is chosen from inter alia Ti (n=2), Zr (n=2), Si (n=2), P (n=1), Al (n=3), and Sb (n=1).