CLC number: X77
On-line Access: 2024-08-27
Received: 2023-10-17
Revision Accepted: 2024-05-08
Crosschecked: 2015-01-23
Cited: 10
Clicked: 6833
Citations: Bibtex RefMan EndNote GB/T7714
Pei-wang Zhu, Hua Dai, Lei Han, Xiu-lin Xu, Le-ming Cheng, Qin-hui Wang, Zheng-lun Shi. Aluminum extraction from coal ash by a two-step acid leaching method[J]. Journal of Zhejiang University Science A, 2015, 16(2): 161-169.
@article{title="Aluminum extraction from coal ash by a two-step acid leaching method",
author="Pei-wang Zhu, Hua Dai, Lei Han, Xiu-lin Xu, Le-ming Cheng, Qin-hui Wang, Zheng-lun Shi",
journal="Journal of Zhejiang University Science A",
volume="16",
number="2",
pages="161-169",
year="2015",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.A1400195"
}
%0 Journal Article
%T Aluminum extraction from coal ash by a two-step acid leaching method
%A Pei-wang Zhu
%A Hua Dai
%A Lei Han
%A Xiu-lin Xu
%A Le-ming Cheng
%A Qin-hui Wang
%A Zheng-lun Shi
%J Journal of Zhejiang University SCIENCE A
%V 16
%N 2
%P 161-169
%@ 1673-565X
%D 2015
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A1400195
TY - JOUR
T1 - Aluminum extraction from coal ash by a two-step acid leaching method
A1 - Pei-wang Zhu
A1 - Hua Dai
A1 - Lei Han
A1 - Xiu-lin Xu
A1 - Le-ming Cheng
A1 - Qin-hui Wang
A1 - Zheng-lun Shi
J0 - Journal of Zhejiang University Science A
VL - 16
IS - 2
SP - 161
EP - 169
%@ 1673-565X
Y1 - 2015
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A1400195
Abstract: To improve aluminum extraction efficiency, a two-step acid leaching process was proposed to dissolve aluminum and aluminum-bearing crystals with sulfuric acid. The first leaching residue (FLR) was obtained through direct leaching of coal ash with sulfuric acid. After roasting a mixture of the FLR and sodium carbonate, the aluminum-bearing crystals in FLR were completely destroyed while sodium silicate was generated. Then the roasted products were leached with water to dissolve the sodium carbonate. X-ray diffraction (XRD) analysis indicated that the water leaching residues (WLR) mainly contained the amorphous phase, which allowed easy aluminum extraction in the second leaching step. In the first leaching test with 10 mol/L sulfuric acid at 120 °C in 2 h and a solid to liquid ratio (S/L) of 1:2, aluminum dissolution from raw coal ash reached 81.72%. In the second leaching step with 5 mol/L sulfuric acid, the aluminum dissolutions from WLR were 87.31% at 20 °C and 99.06% at 100 °C. Total aluminum dissolutions were more than 97%. Moreover, the leaching process produced two by-products, sodium silicate solution and amorphous silicon dioxide, which contained nearly all the silicon from the coal ash.
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