A new method is developed to control water fugacity at a fixed pressure and temperature. We use two divariant phase assemblages (clinohumite–periclase–forsterite and brucite–periclase) in the MgO– SiO2–H2O system and the chemical reactions among co-existing phases buffer the water fugacity. In order to avoid a reaction between the water fugacity buffer and the specimen, a double-capsule assembl...

The volume-increase associated with hydration reactions in rocks may lead to reaction-induced fracturing, but requires a stable water film be present at reactive grain boundaries even when subject compressive stress. Hydration of periclase brucite is solid volume increase ca. 110%. Recent experiments on the periclase-brucite system observed that effective mean stress exceeds 30 MPa, reaction ra...

The composition and properties of two types calcined magnesium oxide powders, differing in chemical composition, are investigated. difference phase determines the different behavior powders during firing, which is smoothed only at a temperature more than 1850 °C. microstructure obtained briquettes differs amount glass phase, type size pores, as well quality crystals periclase. From studied deca...