The behavior of chromium in laminar hydrogen and ethene diffusion flames

Yoon, Youngbin; Reyes, Christopher; Jones, A. Daniel; Kelly, Peter B.; Chang, Dan; Kennedy, Ian M.

doi:10.1016/s0082-0784(96)80018-x

Cited by 4 publications

(1 citation statement)

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“…The chemical reaction of heavy metals with Al or Al-Si compounds to form heavy metal-aluminate or -aluminosilicate is the primary reason for their immobilization. Previous research (Yoon et al, 1996;Kozin ′ ski and Zheng, 1998) discussed the behavior of metals at high temperatures during waste or fuel combustion. However, the chemistry and mechanism of their interaction with an aluminosilicate matrix during combustion and solidification were not well established, so the present work focuses on the chemistry and mechanism of light/heavy metal interaction with an aluminosilicate matrix during ash solidification.…”

Section: Introductionmentioning

confidence: 99%

INTERACTION BETWEEN LIGHT/HEAVY METALS AND Al-Si PHASES FORMED FROM COMBUSTIBLE SOLID RESIDUES

Ramesh

Koziński

2007

Inter J Ener Clean Env

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This paper discusses the characteristics of inorganic solid particles with an emphasis on the relationships between the light/heavy metals and the ash matrix Al-Si compounds during ash solidification. The electron probe microanalysis (EPMA) of the final ash shows the distribution of major elements Al and Si in different phases such as crystalline mullite, corundum, and aluminosilicate glass. It also illustrates that the majority of the Cr coexists with the corundum phase, while Cd, Pb, Na, and K coexist with mullite and aluminosilicate glass. A quantitative analysis of the EPMA results indicates that the surface of the ash particle contains 15.8% (concentration ratio) more of Na and 14.3% more of K than at the core. However, the concentration ratio of Pb and Cd is more at the core (11.8% and 13.2%, respectively) than the surface. The 27 Al and 29 Si solid-state nuclear magnetic resonance spectroscopy (NMR-MAS) and X-ray diffractometry studies also support the formation of three phases in the final ash. The formation of mullite and aluminosilicate amorphous phases is indicated by the presence of 27 Al NMR peaks at 50 ppm (AlO4 tetrahedral group), 8 ppm (AlO6 octahedral group), and a broad 29 Si NMR peak at-99 ppm. The 23 Na NMR spectra show a broad peak around-28.7 ppm due to the Na + present to compensate SiO-. During ash evolution, Cr 3+ replaces Al 3+ in its octahedral sites of corundum/mullite, while Pb 2+ and Cd 2+ either fill oxygen vacancy in mullite or form stable compounds with the glass phase. The results clearly indicate the interaction between light/heavy metals and ash Al-Si matrix compounds.

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Section: Introductionmentioning

confidence: 99%