A systematic investigation into the extraction of aluminum from coal spoil through kaolinite

Journal Article · Sat Nov 15 00:00:00 EST 2008 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es801798u· OSTI ID:21126092

Qiao, X C; Si, P; Yu, J G ^[1]

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1. East China University of Science and Technology, Shanghai (China). School of Resource and Environmental Engineering

This research has applied kaolin and active carbon (AC) to the investigation of the recovery of aluminium from coal spoil (CS). The kaolin, AC-containing kaolin mixture, and CS have been calcined at 500, 600, 700, 800, and 900{degree}C for 15, 30, 60, and 120 min. The transformation of kaolinite and aluminium extraction that occurred in each calcined sample have been characterized using XRD, TG, IR, and hydrochloric acid leaching methods. The dehydroxylation of kaolinite and the decomposition of metakaolin were influenced by thermal treatment temperature and time. The metakaolin had kept a portion of OH- in its structure until it was calcined at a temperature of 800{degree}C. Under 60 min treatment, new SiO{sub 2} phase was able to be formed at 500{degree}C, kaolinite was totally converted to metakaolin at 600{degree}C, and the SiO{sub 2} rejoined the reaction at 800{degree}C. The decompositions of CS were similar to those of kaolin mixture containing 20 wt % AC (MKC). The combustion of combustible matter accelerated the decomposition of kaolinite in the CS and MKC. Higher AC content led to lower aluminum extraction. The treatment at 600{degree}C was optimal for both CS and MKC. 28 refs., 7 figs., 3 tabs.

• OSTI ID: 21126092
• Journal Information: Environmental Science and Technology, Vol. 42, Issue 22; Other Information: [e-mail]; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ALUMINIUM
KAOLINITE
KAOLIN
ACTIVATED CARBON
MATERIALS RECOVERY
PYROLYSIS
DECOMPOSITION
CALCINATION
SILICON OXIDES
COAL
MINERAL WASTES
SOLVENT EXTRACTION
X-RAY DIFFRACTION
THERMAL GRAVIMETRIC ANALYSIS
INFRARED SPECTRA
TEMPERATURE DEPENDENCE
HYDROCHLORIC ACID
DEMETALLIZATION
COMBUSTION
TIME DEPENDENCE
DEHYDROXYLATION