A review of the multi-component utilisation of coal fly ash

The progress in the research and development of high temperature sodium batteries suggests that all-solid-state batteries with inorganic or polymer solid electrolytes are promising power sources for a wide range of applications due to their high thermal stability, reliability, long-cycle life and versatile geometries. The electrolytes play a fundamental role in terms of current (power) density, the time stability, and the safety of batteries and, as a result, their continuous improvement and innovation are indeed critical to success. In fact, inorganic solid electrolytes pave the way for improving the cost-effective development of rechargeable sodium batteries. This review describes a state-of-the-art overview of most of the Na+ conductors for use as electrolytes in sodium/sulphur and ZEBRA batteries. The emphasis of this article is on inorganic solid electrolytes, especially, ceramic and glass-ceramic electrolytes as promising alternatives applicable to all solid-state batteries. As part of a continuous effort to find new materials that operate at room temperature and moderate temperatures, NASICON electrolytes will also be considered. Polymer electrolytes based on poly(ethylene oxide) (PEO) are also very suitable for all solid-state batteries. Hence, the review focuses on ion transport based on the observed conductivity, electrolyte preparation, safety and environmental impact.

High temperature sodium batteries: status, challenges and future trends

A review of the alumina recovery from coal fly ash, with a focus in China

A metal-organic framework material named MIL-53(Fe), iron terephthalate, has been synthesized sovothermally at a relatively low temperature by not only conventional electric (CE) heating, but also by irradiation under ultrasound (US) and microwave (MW) conditions to gain an understanding of the accelerated syntheses induced by US and MW. The kinetics for nucleation and crystal growth were analyzed by measuring the crystallinity of MIL-53(Fe) under various conditions. The nucleation and crystal growth rates were estimated from crystallization curves of the change in crystallinity with reaction time. The activation energies and pre-exponential factors were calculated from Arrhenius plots. It was confirmed that the rate of crystallization (both nucleation and crystal growth) decreases in the order US>MW>>CE, and that the accelerated syntheses under US and MW conditions are due to increased pre-exponential factors rather than decreased activation energies. It is suggested that physical effects such as hot spots are more important than chemical effects in the accelerated syntheses induced by US and MW irradiation. The syntheses were also conducted in two steps to understand quantitatively the acceleration induced by MW and it was found that the acceleration in crystal growth is more important than the acceleration in nucleation, even though both processes are accelerated by MW irradiation.

Synthesis of a metal-organic framework material, iron terephthalate, by ultrasound, microwave, and conventional electric heating: a kinetic study.

Conversion of coal fly ash to zeolite utilizing microwave and ultrasound energies: A review

High purity alum (>99.9%) has been produced by the reaction of NH4Al(SO4)2 derived from coal fly ash and ammonia in water at a controlled pH and then followed by the successive crystallization. The influence of heating source (conventional and microwave) on the decomposition of the alum and the characteristics of the resultant alumina was examined by means of XRD, TG/DTA, SEM and a laser scattering technique. The application of microwave heating for decomposition of the alum yielded finer α-Al2O3 powders with a higher specific surface area, when compared with conventional heating.

Hee Chan Park

Papers

Synthesis of alumina from high purity alum derived from coal fly ash

Conventional versus ultrasonic synthesis of zeolite 4A from kaolin

Synthesis of nickel powders from various aqueous media through chemical reduction method

Preparation of submicron nickel powders by microwave-assisted hydrothermal method

Synthesis of beta-alumina powders by microwave heating from solution-derived precipitates