Mineral transformations during high temperature treatment of anthracite

Rodrigues, Sandra, Marques, Manuela, Ward, Colin R., Suarez-Ruiz, Isabel and Flores, Deolinda (2012) Mineral transformations during high temperature treatment of anthracite. International Journal of Coal Geology, 94 191-200. doi:10.1016/j.coal.2011.09.012

Author Rodrigues, Sandra
Marques, Manuela
Ward, Colin R.
Suarez-Ruiz, Isabel
Flores, Deolinda
Title Mineral transformations during high temperature treatment of anthracite
Journal name International Journal of Coal Geology   Check publisher's open access policy
ISSN 0166-5162
Publication date 2012-05-01
Sub-type Article (original research)
DOI 10.1016/j.coal.2011.09.012
Volume 94
Start page 191
End page 200
Total pages 10
Editor Colin R. Ward
Shifeng Dai
Place of publication Amsterdam, The Netherlands
Publisher Elsevier
Language eng
Formatted abstract
SEM/EDX analysis has been applied in order to assess the mineralogical transformations occurring during high temperature treatment of several different anthracites. At 1000°C (carbonization) loss of CO 2 from carbonates, S from sulfides and OH and/or H 2O from clays occurs, transforming these minerals to other inorganic phases such as lime, pyrrhotite, and (Na, Mg) K-aluminosilicates, among others. Heat treatment of the carbonized samples up to 1500, 2000, and 2500°C resulted in: i) a decrease in oxygenated mineralogical phases, which are transformed to higher temperature silicates (grossite, anorthite, kushiroite, etc.); ii) carbide formation (SiC, TiC or Al 4C 3) by carbothermal reactions; iii) formation of alloys, especially a Pb-Sn alloy; and iv) formation of iron silicides (Fe 2Si), iron phosphides (Fe 3P), and nitrides (TiN and AlN). The new mineral phases are closely related to the mineral matter in the raw anthracite samples. Thus, samples richer in Ca-Mg phases (carbonates and phosphates) produced minerals such as monticellite, pyrope, gehlenite, grossite and kushiroite; samples richer in Al-bearing phases (boehmite and diaspore) gave rise to phases such as mullite, corundum and spinel; and Si-Al bearing phases (clay minerals) were associated with the formation of minerals such as panunzite, plagioclase and cristobalite. At the highest temperature of the process the majority of the elements vaporized, and Ti seems to be the only element in the original mineral matter that withstands treatment to 2500°C.
Keyword Mineral matter
Carbothermal reactions
X-ray diffraction
Carbonized anthracites
HTT (high temperature treatment)
Carbothermal reduction
Microstructural evolution
Carbonized anthracites
Phosphorus minerals
Coal seams
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ
Additional Notes Special issue title: Minerals and Trace Elements in Coal

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Earth Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 5 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 6 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Fri, 16 Aug 2013, 19:25:08 EST by System User on behalf of Scholarly Communication and Digitisation Service