Ultra clean coal production by microwave irradiation pretreatment and sequential leaching with HF followed by HNO3

Jorjani, E., Chapi, H. Ghasemi and Khorami, M. Tayebi (2011) Ultra clean coal production by microwave irradiation pretreatment and sequential leaching with HF followed by HNO3. Fuel Processing Technology, 92 10: 1898-1904. doi:10.1016/j.fuproc.2011.05.008


Author Jorjani, E.
Chapi, H. Ghasemi
Khorami, M. Tayebi
Title Ultra clean coal production by microwave irradiation pretreatment and sequential leaching with HF followed by HNO3
Formatted title
Ultra clean coal production by microwave irradiation pretreatment and sequential leaching with HF followed by HNO3
Journal name Fuel Processing Technology   Check publisher's open access policy
ISSN 0378-3820
1873-7188
Publication date 2011-10
Sub-type Article (original research)
DOI 10.1016/j.fuproc.2011.05.008
Open Access Status
Volume 92
Issue 10
Start page 1898
End page 1904
Total pages 7
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Language eng
Formatted abstract
The goal of this project was to develop and test an innovative coal cleaning process to reduce the ash content of coal and produce ultra clean coal (UCC). Coal samples that were prepared from concentrates of Iran's Zirab and Tabas coal preparation plants were found to have initial ash contents of 8.31 and 10.36%, respectively. These coals were demineralized with the combination of microwave irradiation pretreatment and dual acid leaching processes with HF followed by HNO3 in a batch reactor. For samples that were microwaved and leached with HF, the reduction in ash ranged from 22 to 76% and from 22 to 82% for Zirab and Tabas coal samples, respectively, depending on leaching conditions. Microwave irradiation pretreatment had a positive effect on demineralization with HF, especially for the coarse size fractions. For the fine size fractions, reduced leaching times were found to enhance the effect of microwave irradiation. The microwave-irradiated, HF-leached product was leached further using a 1.4 M HNO3 solution at a leaching temperature of 65 °C to remove fluoride sediments and pyritic sulfur. The ash content of the Zirab coal was reduced from 2.57 to 0.69% by leaching with the HNO3 solution for 1 h. The ash content of the Tabas coal was reduced from 2.44 to 0.39% by leaching with the HNO3 solution for 3 h. The results show that microwave irradiation can be considered as a pretreatment process in the chemical leaching of coal to produce UCC.
Keyword Ultra clean coal
Leaching
Microwave irradiation
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Julius Kruttschnitt Mineral Research Centre Publications
 
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Created: Thu, 01 May 2014, 16:24:24 EST by Maedeh Tayebi-khorami on behalf of Julius Kruttschnitt Mineral Research Centre