Influence of additions on the preparation of ye’elimite from natural phosphate
| dc.contributor.author | Zeyneb HAMMOU Enc/ Hocine BELHOUCHET | |
| dc.date.accessioned | 2025-07-08T10:34:46Z | |
| dc.date.available | 2025-07-08T10:34:46Z | |
| dc.date.issued | 2025 | |
| dc.description.abstract | Cement production is considered a fundamental element in the construction industry, but it contributes significantly to environmental pollution, as it emits one ton of carbon dioxide for every ton of cement produced, representing 5% of global carbon emissions. To address this environmental challenge, scientists are researching the development of more environmentally sustainable alternatives such as ye’elimite-based cement, which is characterized by low carbon emissions and reduced need for limestone in the production process. In the research presented in this thesis, we prepared multi-phase composites based on ye’elimite, using natural phosphate (fluorapatite) from Djebel El Onk in Algeria as an alternative source of CaO instead of limestone. This study also investigates the effect of oxide additives such as natural quartz and magnesium oxide on the behavior and decomposition characteristics of fluorapatite. The study examined the influence of varying SiO2 content (0-5.4 wt%) on the reactive sintering of mixtures containing fluorapatite, bauxite, and gypsum. The resulting composites included multiple phases such as calcium hexaluminate, fluorapatite, ye’elimite, and gehlenite. Quantitative Rietveld analysis revealed that increased quartz content promoted gehlenite formation over ye’elimite at 1300-1350 °C, while also significantly modifying the microstructure-leading to the development of hexagonal and circular grains after heat treatment at 1400 °C. In addition, we examined the effect of MgO on the decomposition of natural fluorapatite during the synthesis of spinel-ye’elimite-based multiphase composites. Using advanced analytical techniques (XRD, Rietveld method, SEM-EDS, FTIR, and TG/DTG), we investigated the influence of temperature (1000-1500 °C) and MgO content (0-6 wt%) on phase formation, including fluorapatite, ye’elimite, spinel, hibonite, beta-tricalcium phosphate, and grossite. The results demonstrate that higher MgO content promotes spinel formation and stabilizes ye’elimite at elevated temperatures. | |
| dc.identifier.uri | https://repository.univ-msila.dz/handle/123456789/46792 | |
| dc.language.iso | en | |
| dc.publisher | UNIVERSITE MOHAMED BOUDIAF - M’SILA | |
| dc.subject | Cement | |
| dc.subject | Natural Phosphate | |
| dc.subject | Fluorapatite | |
| dc.subject | Calcium Sulfoaluminate | |
| dc.subject | Ye’elimite | |
| dc.subject | Rietveld Method. | |
| dc.title | Influence of additions on the preparation of ye’elimite from natural phosphate | |
| dc.type | Thesis |