000079637 001__ 79637
000079637 005__ 20210310171107.0
000079637 0247_ $$2doi$$a10.3390/min9040213
000079637 0248_ $$2sideral$$a112240
000079637 037__ $$aART-2019-112240
000079637 041__ $$aeng
000079637 100__ $$0(orcid)0000-0002-1954-6180$$aLaita, Elisa$$uUniversidad de Zaragoza
000079637 245__ $$aHigh-temperature mineral phases generated in natural clinkers by spontaneous combustion of coal
000079637 260__ $$c2019
000079637 5060_ $$aAccess copy available to the general public$$fUnrestricted
000079637 5203_ $$aThe aim of this study is to analyze natural clinkers (= calcined clays by coal combustion) from a lower Cretaceous coal outcrop in Arino (Teruel, NE Spain) in order to describe mineral and textural transformations produced during the spontaneous combustion of coal. To achieve this aim, samples were analyzed using X-ray diffraction and optical and electron microscopy. Spontaneous combustion resulted in the melting of the surrounding clays, with the generation of an Al-Si-rich vitreous phase. Subsequently, high-temperature phases crystallized from this vitreous phase. These new minerals are interesting due to their similarity with those formed during ceramic processes, used in the manufacture of stoneware and ceramic tiles, as well as in refractory ceramics, and with natural events such as metamorphic and igneous processes. The studied natural clinkers are composed of vitreous phase mullite, hematite, hercynite, cristobalite, quartz, pyroxenes, cordierite, gypsum, pyrite, and calcium oxides. A trend from hematite to hercynite composition indicates compositional variations at sample scale, which evidence d-spacing differences in hercynite and may be related to the Al and Fe content in hercynite depending on its texture. The mullite shows higher Si/Al ratio (1.21) than the theoretical composition (0.35), indicating that this mullite is more Si-rich. Three pyroxene-type compositions (diopside-type, ferrosilite-type, and a Ca-Al-rich pyroxene) were found. Both the mullite and the pyroxenes are nonstoichiometric.
000079637 536__ $$9info:eu-repo/grantAgreement/ES/MINECO-FEDER/CGL2017-85038-P
000079637 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000079637 590__ $$a2.38$$b2019
000079637 591__ $$aMINING & MINERAL PROCESSING$$b6 / 21 = 0.286$$c2019$$dQ2$$eT1
000079637 591__ $$aMINERALOGY$$b11 / 30 = 0.367$$c2019$$dQ2$$eT2
000079637 592__ $$a0.494$$b2019
000079637 593__ $$aGeotechnical Engineering and Engineering Geology$$c2019$$dQ2
000079637 593__ $$aGeology$$c2019$$dQ2
000079637 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000079637 700__ $$0(orcid)0000-0002-4970-6333$$aBauluz, Blanca$$uUniversidad de Zaragoza
000079637 700__ $$0(orcid)0000-0002-2169-4561$$aYuste, Alfonso$$uUniversidad de Zaragoza
000079637 7102_ $$12000$$2120$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Cristalografía Mineralog.
000079637 773__ $$g9, 4 (2019), Art.213 [17 p.]$$pMinerals (Basel)$$tMinerals$$x2075-163X
000079637 8564_ $$s748604$$uhttps://zaguan.unizar.es/record/79637/files/texto_completo.pdf$$yVersión publicada
000079637 8564_ $$s105305$$uhttps://zaguan.unizar.es/record/79637/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000079637 909CO $$ooai:zaguan.unizar.es:79637$$particulos$$pdriver
000079637 951__ $$a2021-03-10-17:01:17
000079637 980__ $$aARTICLE