Preparation of crystalline Mg(OH)2 nanopowder from serpentinite mineral

In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array (Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 C followed by NH4OH titration for Mg(OH)2 precipitation was demonstrate

Structure and properties of the hardmetal coatings Cr3C2-25NiCr formed by a multi-chamber detonation sprayer

The hardmetal Cr3C2-25NiCr (180-220 μm thick) coatings have been produced on a steel substrate by a multi-chamber detonation sprayer (MCDS). The microstructures and properties of the hardmetal coatings were examined with the use of optical microscopy, scanning electron microscopy, X-ray phase analysis, and a Vickers hardness tester with a 300 g test loa

Preparation of crystalline Mg(OH)2 nanopowder from serpentinite mineral

In this paper we describe a route to produce crystalline Mg(OH)2 nanopowders from serpentinite ore distributed in the Halilovskiy array (Russia, Orenburg region). An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 °C followed by NH4OH titration for Mg(OH)2 precipitation was demonstrated. In this study, crystalline Mg(OH)2 nanopowders have been synthesized by solvothermal reaction method using (Mg(NO3)2⋅6H2O) which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray phase analysis (XRD), and inductively coupled plasma optical emission spectroscopy (ICP-OES). XRD reveals that Mg(OH)2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg(OH)2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg(OH)2 are 30–265 nm length or width. Keywords: Serpentinite, Nitric acid leaching, Magnesium hydroxide, Solvothermal reaction method, Crystalline Mg(OH)2 nanopowde

Synthesis of Magnesium Oxide Nanopowder by Thermal Plasma Using Magnesium Nitrate Hexahydrate

Magnesium oxide (MgO) nanopowder was synthesized by thermal plasma in a novel thermal DC plasma torch using magnesium nitrate hexahydrate. Magnesium nitrate hexahydrate (Mg(NO3)2·6H2O) was obtained from serpentinite (Mg3Si2O5(OH)4; lizardite) (Halilovskiy array, Orenburg region, Russia). The synthesized samples were characterized by analytical techniques including X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM characterization studies confirmed that MgO nanopowder obtained has periclase structure with high purity, and the particle sizes vary within the range of 100 nm to 150 nm. We believe that the present work will promote further experimental studies on the physical properties and the applications of MgO nanopowders in the fields such as high-densed ceramics, additives in bactericide, and refractory products