Thermal treatment and phase formation in kaolinite and illite based clays from tropical regions of BoliviaReport as inadecuate




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Luleå University of Technology, Department of Engineering Sciences and Mathematics.Antti, Marta-Lena Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.Odén, Magnus ORCID iD: 0000-0002-2286-5588 2012 (English)In: 6th EEIGM International Conference Advanced Materials Research: 7th and 8th November, 2011 EEIGM, Nancy, France, Bristol: IOP Publishing Ltd , 2012Conference paper, Published paper (Refereed)

Abstract [en] : The aim of this study was to compare the thermal behaviour of clays containing illite and kaolinite in various proportions. The clays contained small amounts of K and Fe, which act as fluxing agents. In order to investigate the phase formations during heating, the samples were examined in a differential scanning calorimeter at temperatures up to 1300°C. The thermal expansion of the samples was determined by dilatometer measurements from room temperature up to 1150°C. Phases were identified using x-ray diffraction and scanning electron microscopy. In all samples, most of the kaolinite was transformed into metakaolinite during heating up to 650°C, while illite remained unchanged up to 950°C. There was no influence of K and Fe on dehydroxylation. Metakaolinite formed at temperatures above 950°C leading to a Si-Al spinel. Furthermore, mullite was formed in the temperature interval 1050-1150°C. In this temperature range, the mechanism of mullite formation depended on the amount of K and Fe in the samples, changing the temperature of formation of mullite. It was observed by x-ray diffraction that most of the illite was transformed into a Si-Al spinel phase at 1050°C, and during further heating transformed into mullite. An increased amount of illite in the clays slightly decreased the melting temperature. The dilatometer measurements showed expansion and shrinkage for the dehydroxylation and spinel-phase formation, respectively.

Place, publisher, year, edition, pages: Bristol: IOP Publishing Ltd , 2012.

Series : I O P Conference Series: Materials Science and Engineering, ISSN 1757-8981 ; 31

National Category : Other Materials Engineering

Research subject: Engineering Materials

Identifiers: URN: urn:nbn:se:ltu:diva-39476DOI: 10.1088/1757-899X/31/1/012017Local ID: e406eefb-6bbe-4f9e-9c54-39379d112618OAI: oai:DiVA.org:ltu-39476DiVA: diva2:1012989

Conference: EEIGM International Conference on Advanced Materials Research : 11/06/2015 - 12/06/2015

Note: Validerad; 2012; Bibliografisk uppgift: Article number 012017; 20111206 (ysko)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-01-19Bibliographically approved



Author: Escalera, Edwin

Source: http://ltu.diva-portal.org/







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