Seawater is constantly circulating through oceanic basement as a low-temperature hydrothermal fluid (<150 degrees C). In cases when ultramafic rocks are exposed to the fluids, for instance during the initial phase of subduction, ferromagnesian minerals are altered in contact with the water, leading to high pH and formation of secondary magnesium hydroxide, among other--brucite, that may scaveng...

Hydrotalcite like precursors containing Pd–Mg–Al with varying molar ratios, (Pd + Mg)/Al ≈ 3 and Mg/Pd ≈ 750 to 35, were prepared by coprecipitation of metal nitrates at constant pH. Characterization of samples as synthesized and their calcined products by elemental analyses, powder XRD, TG–DTA, FT–IR spectroscopy, TPR and N2 physisorption indicated a well crystalline hydrotalcite like structur...

Introduction The extraction of alumina from bauxite by the Bayer process produces a slurry by-product referred to as ‘bauxite residue’ or ‘red mud’. The liquid component of the slurry is highly alkaline and requires neutralisation to render it environmentally benign. A common practice is neutralisation using Mg rich seawater, which results in the formation of the layered double hydroxide (LDH) ...

Magnesium hydroxide Mg(OH)2 nanorods with diameters of 90±10nm and lengths of more than 2μms were prepared by a simple route at ~75oC in ambient air. The approach is based on reaction of magnesium powder and de-ionized water without the use of any harmful, toxic or corrosive reagents. Characterization using X-ray diffraction (XRD) shows single crystalline structure of Mg(O...

Mid-infrared (IR) spectra of a series of calcium silicate hydrates (C-S-H) gels synthesised from C3S in the presence of magnesium oxide show many similarities with the mid-IR spectra of pure C-S-H gels. However, the presence of the vibration bands attributed to brucite is observed in all spectra of C-S-H synthesised with MgO, although only the sample with the highest CaO/SiO2 ratio (1.8) reveal...