TITLE:
Dissolution of Rare Earth Elements from Coal Fly Ash Particles in a Dilute H2SO4 Solvent
AUTHORS:
Shunsuke Kashiwakura, Yuichi Kumagai, Hiroshi Kubo, Kazuaki Wagatsuma
KEYWORDS:
Coal Fly Ash; Rare Earth Elements; Dissolution Behavior; Unreacted Core Model
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.3 No.2,
May
23,
2013
ABSTRACT: Recently, the worldwide supply of rare
earth element (REE) resources will be severely restricted. On the other hand,
coal fly ash particles emitted from coal-fired electric power plants contain
relatively high concentrations of REEs. The contents of REEs in coal fly ash
are regularly several hundreds of ppmw. In order to extract and recover REEs
from coal fly ash particles, as a first step, we have investigated their
dissolution behavior in a dilute H2SO4 solvent. The REE
content of coal fly ash specimens has been precisely determined, and their
presence in the ash component of the original coal and their enrichment in coal
fly ash particles during coal combustion have been suggested. REEs in coal fly
ash dissolve gradually in H2SO4 over time, and this
implies two types of occurrences of the REEs in coal fly ash particles. By
applying the unreacted core model to the dissolution behavior of REEs in a H2SO4 solvent, we can explain both types of occurrences.