TY - JOUR
T1 - Effect of natural dolomite calcination temperature on sorption of borate onto calcined products
AU - Sasaki, Keiko
AU - Qiu, Xinhong
AU - Hosomomi, Yukiho
AU - Moriyama, Sayo
AU - Hirajima, Tsuyoshi
N1 - Funding Information:
Financial support was provided to K.S. by Funding Program for Next Generation of World-Leading Researchers (“NEXT program” GR078 ) in Japan Society for Promotion of Science (JSPS). Specimens of natural dolomite were supplied by courtesy of Yoshizawa Lime Co., Ltd. Calcination equipment under reducing conditions was used by courtesy of Prof. Kunihiko Nakashima at Department of Material Engineering, Kyushu University. XPS spectra were collected in the Advanced Analytical Center, Kyushu University, and TEM observation was carried out in the Research Laboratory for High Voltage Electron Microscopy (HVEM), Kyushu University.
PY - 2013
Y1 - 2013
N2 - Natural dolomite was calcined at 700-900 °C under air and an Ar gas flow atmosphere to characterize its sorbency potential for borate. A sequential decarbonation occurred with increase in calcination temperature, that is, transformation of CaMg(CO3)2 to MgO and CaCO3 up to 700 °C and CaCO3 to CaO from 700 to 900 °C. The surface molar ratio of Ca/Mg decreased from 1.6 to 0.6 by calcination at more than 700 °C, owing to the crystal growth of MgO toward the surfaces. MgO crystal growth is responsible for hydration leading to borate co-precipitation. The sorption density of borate was greater with the calcined products at 700 °C than 800-900 °C and under an Ar gas flow system rather than for static air at the same temperatures. The surface reactivity of the calcined dolomite with borate in the aqueous phase was affected by CO2 emitted in the decarbonation at higher temperatures.
AB - Natural dolomite was calcined at 700-900 °C under air and an Ar gas flow atmosphere to characterize its sorbency potential for borate. A sequential decarbonation occurred with increase in calcination temperature, that is, transformation of CaMg(CO3)2 to MgO and CaCO3 up to 700 °C and CaCO3 to CaO from 700 to 900 °C. The surface molar ratio of Ca/Mg decreased from 1.6 to 0.6 by calcination at more than 700 °C, owing to the crystal growth of MgO toward the surfaces. MgO crystal growth is responsible for hydration leading to borate co-precipitation. The sorption density of borate was greater with the calcined products at 700 °C than 800-900 °C and under an Ar gas flow system rather than for static air at the same temperatures. The surface reactivity of the calcined dolomite with borate in the aqueous phase was affected by CO2 emitted in the decarbonation at higher temperatures.
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U2 - 10.1016/j.micromeso.2012.12.029
DO - 10.1016/j.micromeso.2012.12.029
M3 - Article
AN - SCOPUS:84873026684
SN - 1387-1811
VL - 171
SP - 1
EP - 8
JO - Zeolites
JF - Zeolites
ER -