Characteristics and Structure of Hopeite-Mineral (Type A3(PO4)2.4H2O)

Aji Syailendra Ubaidillah, Lutfian Rusdi Daryono, Arifudin Idrus, I Wayan Warmada, Karsten Knorr

Abstract


The aim of the study was to gain more information about the structural changes during the dewatering reactions of the above compounds. The paper is focus on the low-temperature absorption of hopeite clay mineral, afterward the phases are examined for the dependence of temperature at different pressures. Hopeite shows signs of a phase transformation. Their use for the dental cement industry as a lubricant for cold-rolling mills is to be emphasized, such as coating with phosphate mineral or carbonaceous crystal. This is shown by the appearance of the new reflexes. The observed changes take place below the dewatering known from the literature. The phase change was investigated using a neutron scattering experiment. A temperature-pressure phase diagram of the dewatering could be set up in the range of 275 K to 380 K and 10-3 mBar to 103 mBar with the temperature-dependent powder diffractometer at different pressures and the temperature-dependent neutron scattering experiment. In this work, it has been proved that the dewatering of the hopeite is dependent on pressure and that the dewatering process of the hopeite is a reversible process.

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References


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DOI: https://doi.org/10.24203/ajas.v7i1.5707

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