Publications Internationales

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    Effect of alkaline carbonate-based activators on the properties of one-part ternary hybrid cement
    (Elsevier, 2024) Oualit, Mehena; Sarri, Arezki
    This paper investigates the use of solid alkaline carbonates (Na2CO3 and K2CO3) as activators for the production of one-part hybrid cement from a combination of three precursors: blast furnace slag, metakaolin, and clinker. The impact of activator dosage and the nature of the alkaline cation (Na+ or K+) on the compressive strength (Cs) and microstructure of the elaborated materials was studied. The results indicate that the highest Cs values are achieved with 5 % Na2CO3. The analysis of the reaction products’ microstructure reveals that the inclusion of Na2CO3 mainly produces (N,C)-A-S-H and C-A-S-H cementitious gels, along with metastable carboaluminates and different types of calcium carbonate. Additionally, the presence of K2CO3 results in the creation of hemicarboaluminate.
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    Cu2O addition and sintering temperature dependence of structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics
    (Elsevier, 2020) Djafar, Rabah; Boumchedda, K.; Chaouchi, A.; Fasquelle, D.; Sedda, K.; Brahimi, S.; Khalfaoui, K.; Bououdina, M.
    This study is aimed in the replacement of commonly used (CuO) by Cu2O in the synthesis of perovskite CaCu3Ti4O12 (CCTO) phase by the solid-state reaction method. The XRD analysis of powder calcined at 1100 °C and ceramics sintered at different temperatures show that the CCTO phase was well crystallized with the presence of small quantities of additional phases. The SEM/EDS analysis of prepared pellets show that the formation of Cu2O/CuO phase occurs above 950 °C, resulting in enhanced densification at 1050 °C (>96%). However, it is found that the Cu2O-based CCTO begins to degrade around 1090 °C. The densification after sintering at 1050 °C reaches 96%, meanwhile dielectric constant and loss tangent values are optimum in the low frequency range (<103 Hz); i.e. 13378 and 0.177, respectively. This favors the use of Cu2O instead of CuO in CCTO ceramics for applications at low frequencies
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    Ain barbar feldspar magnetic beneficiation
    (Polish Mineral Engineering Society, 2014) Kecir, Mohamed; Zibouche, M'Hamed; Kecir, Arbia
    Though Algeria has many mineral resources which have been already developed, there are other resources that have to be valued such as feldspar. This paper deals with potassium feldspar from Ain Barbar deposit. The demand for feldspar as a raw material for the ceramic industry is continuously increasing, which implies an increase in the imports of this material. It became therefore imperative to develop the deposit in question. The ore contains essentially quartz, potassium oxide and iron with respective grades: 74.97% SiO2, 10.43% K2O and 0.60% Fe2O3. This latter is one of the principal impurities which will impart color and in turn degrade the quality of the ore. The objective of this work is to reduce the iron found in oxide form. For this purpose, we used High Gradient Magnetic Separation (HGMS), firstly by the dry process. This operation has allowed to reduce the iron content, from 0.60 to 0.40% Fe2O3, which is acceptable only for stoneware tiles paste of type "porcellenato". To further reduce this iron oxide content, a wet HGMS has been realized on a finer grain size (-40+20μm) and allowed to obtain a product with 0.19% Fe2O3, which can be used in the sanitary ceramics industry
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    Thermal behaviour of kaolin of tamazert (Algeria) deposit
    (2012) Zibouche, Fatima; Kerdjoudj, H.; Abadlia, Mohamed Tahar
    Kaolin from Tamazert deposit in the north Algeria was used in this study. The physical and chemical properties were determined by the performance of several analyses as well as the X-ray fluorescence, X-ray diffraction, thermal behaviour (ATD, TG), dilatometric and granulometric distribution. The study of ceramic behaviour as function of firing temperature has been investigated by shrinkage, adsorption both density and mechanical tests after gradually increasing from room temperature to 1500 °C. The modification of the structure of the raw material samples has been observed after fining and the crystallization of mullite and amorphous silica phase were confirmed by scanning microscopy SEM and evaluated by XRD. The suitability of kaolin for ceramics process was discussed from the linear shrinkage, both density and open porosity. The amorphous phase content is varied from 27-34 % and the tests of flexion have been carried out as depending of temperature, revealed a suitable mechanical properties and the relationship between amorphous phase and sample properties. The adsorption rate was found to be about 35%