Investigation and Preparation of High Active Nano-MgO Thin Spherical Material

Abstract

High active MgO precursor was prepared by high-temperature spray thermal decomposition method using saturated MgCl₂ as raw materials. And high active nano-MgO thin spherical materials were prepared by MgO precursor being calcined at different temperatures after multiple hydration, purification, and filtration. The XRD, TG, DSC and SEM were employed to characterize the phase structure and micro-morphology of spherical materials whose formation mechanism was researched. And its activity (average pore size and surface area) was detected by using BET-BJH of N₂ adsorption to get the optimum calcination temperature. The results showed that high active nano-MgO thin spherical material was periclase structure, its surface of nano-flake or rod-like, and thin sphere with diameter of 30∼100 nm and aperture of 10∼60 nm. The aperture was decreased while the surface area, microporous volume and surface activity were increased with preparation process were optimized, for example, calcination temperatures. Nano-MgO thin spherical material with a purity of 99.2 wt% was obtained at 900°C. And BET surface area of nano-sphere reached a maximum value of 31.6 m²/g with nest-like structure of particle uniform dispersion and average aperture of 11.2 nm. Meanwhile, the maximum absorption of N₂ was gotten.

Keywords:

• High-temperature spray
• MgO thin sphere
• nano-structure
• BET surface area