TY - JOUR
T1 - Extraction of Gallium from Brown Corundum Dust by Roasting—Acid Leaching Process
AU - Zhang, Juhua
AU - Chang, Yuwei
AU - Gao, Cong
AU - Hui, Xujie
AU - Jokilaakso, Ari
N1 - Publisher Copyright:
© 2023 by the authors.
PY - 2023/7
Y1 - 2023/7
N2 - Brown corundum dust is a solid waste produced during the preparation of brown corundum with bauxite as the raw material. The dust has a relatively high gallium content; therefore, it is of great value to recover the gallium from this kind of dust. In this paper, a range of analysis and characterization methods, including XRD, XRF, SEM-EDS, and EPMA, were used to determine the occurrence of gallium. It was found that gallium was mainly present in the potassium-rich phase, wrapped by amorphous silicate and the corundum phase. Roasting activation followed by an acid leaching process was proposed to extract gallium from brown corundum dust. An investigation was carried out on the effects of roasting temperature, roasting time, and additive dosage on the recovery of gallium and the evolution of the phase composition of the dust. The results show that the roasting activation of sodium carbonate was better than that of calcium oxide. After roasting at 1073 K for 40 min with a sodium carbonate dosage of 0.5 (mass ratio of sodium carbonate to dust), the phase composition changed completely to mainly consist of sodium silicate, sodium aluminosilicate, and potassium aluminosilicate. In that case, around 93% of Ga could be recovered from the roasted dust through H2SO4 (4.6 mol/L) leaching for 90 min. The leaching process was described well by the kinetic equation of k3t = 1/(1 − α)1/3 − 1, with an apparent activation energy of 16.81 kJ/mol, suggesting that the leaching rate was limited by the transfer of leaching agent across the contacting interface of the dust particles.
AB - Brown corundum dust is a solid waste produced during the preparation of brown corundum with bauxite as the raw material. The dust has a relatively high gallium content; therefore, it is of great value to recover the gallium from this kind of dust. In this paper, a range of analysis and characterization methods, including XRD, XRF, SEM-EDS, and EPMA, were used to determine the occurrence of gallium. It was found that gallium was mainly present in the potassium-rich phase, wrapped by amorphous silicate and the corundum phase. Roasting activation followed by an acid leaching process was proposed to extract gallium from brown corundum dust. An investigation was carried out on the effects of roasting temperature, roasting time, and additive dosage on the recovery of gallium and the evolution of the phase composition of the dust. The results show that the roasting activation of sodium carbonate was better than that of calcium oxide. After roasting at 1073 K for 40 min with a sodium carbonate dosage of 0.5 (mass ratio of sodium carbonate to dust), the phase composition changed completely to mainly consist of sodium silicate, sodium aluminosilicate, and potassium aluminosilicate. In that case, around 93% of Ga could be recovered from the roasted dust through H2SO4 (4.6 mol/L) leaching for 90 min. The leaching process was described well by the kinetic equation of k3t = 1/(1 − α)1/3 − 1, with an apparent activation energy of 16.81 kJ/mol, suggesting that the leaching rate was limited by the transfer of leaching agent across the contacting interface of the dust particles.
KW - amorphous silicate
KW - calcium oxide
KW - leaching kinetics
KW - roasting activation
KW - sodium carbonate
UR - http://www.scopus.com/inward/record.url?scp=85166193400&partnerID=8YFLogxK
U2 - 10.3390/min13070900
DO - 10.3390/min13070900
M3 - Article
AN - SCOPUS:85166193400
SN - 2075-163X
VL - 13
JO - Minerals
JF - Minerals
IS - 7
M1 - 900
ER -