TY - JOUR
T1 - Synthesis, thermodynamic, and kinetics of rubidium jarosite decomposition in calcium hydroxide solutions
AU - Perez-Labra, Miguel
AU - Romero-Serrano, Antonio
AU - Salinas-Rodriguez, Eleazar
AU - Avila-Davila, Erika O.
AU - Reyes-Perez, Martin
PY - 2012/8
Y1 - 2012/8
N2 - Rubidium jarosite was synthesized as a single phase by precipitation from aqueous solution. X-ray diffraction and scanning electron microscopy energy-dispersive spectrometry analysis showed that the synthetic product is a solid rubidium jarosite phase formed in spherical particles with an average particle size of about 35 μm. The chemical analysis showed an approximate formula of Rb 0.9432Fe 3(SO 4) 2.1245(OH) 6. The decomposition of jarosite in terms of solution pH was thermodynamically modeled using FACTSage by constructing the potential pH diagram at 298 K (25 °C). The E-pH diagram showed that the decomposition of jarosite leads to a goethite compound (FeO•OH) together with Rb + and $$ {\text{SO}}-{4}^{2 - } $$ ions. The experimental Rb-jarosite decomposition was carried out in alkaline solutions with five different Ca(OH) 2 concentrations. The decomposition process showed a so-called "induction period" followed by a progressive conversion period where Rb + and $$ {\text{SO}}-{4}^{2 - } $$ ions formed in the aqueous solutions, whereas calcium was incorporated in the solid residue and iron gave way to goethite. The kinetic analysis showed that this process can be represented by the shrinking core chemically controlled model with a reaction order with respect to Ca(OH) 2 equals 0.4342 and the calculated activation energy is 98.70 kJ mol -1.
AB - Rubidium jarosite was synthesized as a single phase by precipitation from aqueous solution. X-ray diffraction and scanning electron microscopy energy-dispersive spectrometry analysis showed that the synthetic product is a solid rubidium jarosite phase formed in spherical particles with an average particle size of about 35 μm. The chemical analysis showed an approximate formula of Rb 0.9432Fe 3(SO 4) 2.1245(OH) 6. The decomposition of jarosite in terms of solution pH was thermodynamically modeled using FACTSage by constructing the potential pH diagram at 298 K (25 °C). The E-pH diagram showed that the decomposition of jarosite leads to a goethite compound (FeO•OH) together with Rb + and $$ {\text{SO}}-{4}^{2 - } $$ ions. The experimental Rb-jarosite decomposition was carried out in alkaline solutions with five different Ca(OH) 2 concentrations. The decomposition process showed a so-called "induction period" followed by a progressive conversion period where Rb + and $$ {\text{SO}}-{4}^{2 - } $$ ions formed in the aqueous solutions, whereas calcium was incorporated in the solid residue and iron gave way to goethite. The kinetic analysis showed that this process can be represented by the shrinking core chemically controlled model with a reaction order with respect to Ca(OH) 2 equals 0.4342 and the calculated activation energy is 98.70 kJ mol -1.
UR - http://www.scopus.com/inward/record.url?scp=84865345181&partnerID=8YFLogxK
U2 - 10.1007/s11663-011-9601-7
DO - 10.1007/s11663-011-9601-7
M3 - Artículo
AN - SCOPUS:84865345181
SN - 1073-5615
VL - 43
SP - 773
EP - 780
JO - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
JF - Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science
IS - 4
ER -