Investigation of the use of enriched rare earth elements located at Eskişehir Kızılcaören region in SiAlON based materials

ABSTRACT Master of Science Thesis INVESTIGATION OF THE USE OF ENRICHED RARE EARTH ELEMENTS LOCATED AT ESKİŞEHİR KIZILCAÖREN REGION IN SiAlON BASED MATERIALS AYŞE KALEMTAŞ Anadolu University Graduate School of Natural and Applied Sciences Ceramic Engineering Program Supervisor: Assist. Prof. Dr. Cemail AKSEL 2002, 65 pages In this study, the use of enriched Eskişehir Kızılcaören region rare earth elements in (3-SiAlON, oxynitride glasses and glass ceramics was investigated. Due to the high La content in P-SiAlON samples, full densification was only obtained by gas pressure sintering. XRD and SEM characterisation of the sintered samples containing, i) commercially available rare earth oxides and ii) enriched rare earth elements, revealed that their structures are similar to each other. After heat treatment of the oxynitride glasses, which was prepared with commercially available rare earth oxides and enriched rare earth elements, different crystallisation behaviour was observed. These results can be due to the existence of some impurities in the enriched rare earth element concentrate. Experimental studies showed that enriched rare earth elements have potential for application areas such as SiAlON ceramics, oxynitride glass and glass ceramics. However, further investigation is required to use these materials widely. Keywords: Enriched rare earth elements, (3-SiAlON ceramics, oxynitride glasses and glass-ceramics 11