Differential behaviour of combustion and gasification fly ash from Puertollano Power Plants (Spain) for the synthesis of zeolites and silica extraction

Fly ash from a Mexican mineral coal I: Mineralogical and chemical characterization

“…It contained low K 2 O (1.3%), Na 2 O (0.4%), TiO 2 (0.9%), and P 2 O 5 (0.04%) levels compared with European fly ash. MFA also had similar properties to fly ashes reported as raw materials used to synthesize zeolites [36] and geopolymers [6], and for silica extraction [24,37].…”

“…Fly ashes have been applied in composite cements [17,18], as a support for catalysts [19], as raw material for the recovery of highly valued metals [20,21], in concrete [22], in silica extraction [23], and in low Si/Al zeolite synthesis [24]. According to our own results, zeolitization of MFA results in faujasite X, analcime, and P and W zeolites [25].…”

“…Additionally, Puertollano Spanish fly ash has been specifically used for comparative purposes as it has proven to be one of the most successful fly ashes in regard to silica extraction [23] and further zeolitization [24]. The composition of MFA and a fly ash certified standard (NBS 1633b), as well as European and English fly ash data, are shown in Table 1.…”

A simple thermogravimetric method for the evaluation of the degree of fly ash conversion into zeolite material

“…The majority of authors [7][8][9][10][11][12][13] determines the fly ashto-zeolite conversion degree in an indirect manner by testing the cation exchange capacity, CEC. The fly ash-tozeolite conversion factor is determined in this method by comparing the CEC value obtained for the fly ash zeolite material with the CEC value for the commercial zeolite of a purity of approx.…”

Bench-scale synthesis of zeolite A from subbituminous coal ashes with high crystalline silica content

“…Wide variety of zeolites including zeolite A (Rayalu et al, 2001), phillipsite and faujasite (Rujiwatra et al, 2005) and GIS-type zeolites (Mouhtaris et al, 2003) were synthesized from low-rank lignite fly ash containing high amount of amorphous phases. Whereas a group of zeolites including zeolite X (Font et al, 2009), phillipsite and hydroxylcancrinite (Nascimento et al, 2009) were synthesized from higher rank coal fly ashes.…”