Synthesis and characterization of lithium zeolites with ABW type from coal fly ash

Abstract

Lithium zeolites with ABW framework were synthesized from coal fly ash by hydrothermal method. The effects of LiOH·H2O concentrations, hydrothermal temperatures, and reaction time on zeolites formation were investigated. LiOH·H2O acted as a strong activator and promoted the dissolution of coal fly ash. The contents of zeolites ABW phases increased at the expense of quartz and mullite in fly ash with an increase of alkaline solution concentrations. On increasing hydrothermal temperatures and time, the soluble species recrystallized and phase transformation between different zeolites was observed. Morphology evolution revealed that the zeolites developed from radiating cluster to mono‐column. The reaction mechanisms were proposed as well. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 790–796, 2013

A comprehensive review on the applications of coal fly ash

“…Three steps, namely dissolution, condensation and crystallization, exist in an alkali hydrothermal reaction for zeolite synthesis. In our previous study [136], including an alkaline fusion followed by hydrothermal treatment [140], and the application of microwave-assisted zeolite synthesis [141]. Shigemoto et al [138] prepared Na-X zeolite from coal fly ash by fusion with sodium hydroxide prior to hydrothermal reaction.…”

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

“…More than 40% of the bauxite has been supplied from imports in recent years, 90% of which are from Indonesia and Australia. 20 The feasibility of alumina recovery from fly ash mainly depends on its alumina content. Usually fly ash with alumina content of more than 30% can be considered feasible for the recovery of alumina.…”

“…For example, about 20% of the fly ash generated is being used in concrete production. Other uses include soil amelioration [4][5][6], ceramic industry [7][8][9], catalysis and support for catalysis [10][11][12][13], adsorbents for removal of various pollutants [14], depth separation [15][16][17], zeolite synthesis [18][19][20] and valuable metals recovery [21][22][23]. The global average utilization rate of fly ash is estimated to be nearly 25% [24].…”

A review on improvement of coal-fired power plants and environmental benefits of ash utilisation

“…For example, about 20% of the FA generated is being used in concrete production. Other uses include soil amelioration (Yao et al, 2014;Manoharan et al, 2010;Lee et al, 2006), ceramic industry (Yao et al, 2011;Erol et al, 2008), catalysis and support for catalysis (Saputra et al, 2012;Jain et al, 2010), adsorbents for removal of various pollutants (Wang and Wu, 2006), depth separation (Hirajima et al, 2010;Shoumkova, 2011), zeolite synthesis (Yao et al, 2013;Chareonpanich et al, 2004) and valuable metals recovery (Arroyo et al, 2011;Hernandez et al, 2006).…”