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This work is based on the valorization and characterization of Moroccan geomaterials (MG) in the ceramic field. The raw materials (Kaolinitic clay of Oulmes: (KC); Red clay of Safi: (SC); Marl of Fez: (FM); Andalusite rich Schists of Oulmes: (AS); Magnesite of Boudkek: (Mag)) have been selected and characterized in terms of chemical, mineralogical composition, and thermal behavior wherein performed. The sintered ceramics (up to 1400 °C) resulted from these natural substances were tested mainly by physical, mechanical, and synthesized phase composition, as well as microstructural analysis, to determine their characteristics. As a result, the ceramic materials based on mullite and periclase have been obtained and confirmed by the X-ray diffraction and the scanning electron microscopy.

This study presents the effect of slaked lime (Ca(OH)2) on the physical and microstructural properties of geopolymers based on natural Moroccan pozzolan. The slaked lime was incorporated at 4, 8, and 12% replacement by weight of pozzolan. Aqueous solutions of sodium hydroxide (NaOH) with different molarities (4, 6, 8, 10, and 12 M) and sodium silicate (Na2SiO3) were used as alkali activators. The molarity of 8 M NaOH was selected as the optimal concentration. The effect of slaked lime was evaluated by measuring the compressive strength (Rc), P wave propagation velocity (Vp), bulk density (D), porosity (P), and water absorption (A). Complementary studies using X-ray diffraction (XRD) and scanning electron microscopy (SEM) were also performed. The results revealed that the incorporation of 8% of slaked lime catalyzed the geopolymerization reaction and promoted the dissolution of the crystalline phases as well as the amorphous phase of pozzolan. These improvements in the geopolymerization reaction resulted in the formation of new phases such as phillipsite-type calcium zeolite and calcium aluminosilicate hydrate, producing the best-performing geopolymer from a physico-mechanical point of view (Rc = 23.05 MPa, Vp = 2.21 km/s, D = 2.05 g/cm3, P = 5.13%, and A = 2.49%).

Processing of magnesia based ceramic by unidirectional dry pressing from Moroccan magnesite is described. The applied magnesite was characterized in terms of its composition, granulometric analysis, surface specific area, and thermal behavior. After appropriate processing, the prepared specimens were fired at various temperatures up to 1350 °C to study the ceramic properties. The ceramic material resulted after firing was investigated regarding the phases composition, structural characteristics, and physical properties of technological interest. On this way, the production of materials having interesting properties such as shrinkage, porosity, density, flexural strength, toughness, dielectric constant, and thermal conductivity is achieved. An X-ray diffraction (XRD) analysis showed that the ceramic sample is composed of periclase as major phase and monticellite and calcium alumino-ferrite as minor phases. The content of amorphous phase that governs the sample properties varies between 26.5 and 31%. Thermal shock tests realized in water showed that the ceramic sample presents good thermal shock resistance. The results revealed that Moroccan magnesite has qualities necessary for the manufacture of ceramic products.

This work proposes the mixing of two varieties of Moroccan clay (C1 and C2) with silica sand in order to minimize the amount of the feldspar used. The raw materials were previously characterized in terms of their composition and thermal behavior. Two formulations noted M1 and M2 were elaborated according to the experimental protocol and they were evaluated in terms of their mechanical and thermal characteristics. The addition of C2 clay in the formulation allows a reduction in the amounts of feldspar of the order of 5%, while improving the technological characteristics of this new ceramic (M2) compared to that obtained by the conventional formulation. Indeed, the obtained ceramic (M2) shows the following characteristics: porosity (11.65%); density (2.71 g/cm 3 ); shrinkage (4.91%); flexural strength (30.05 N mm −2 ) and thermal conductivity (2.73 W/mK). Results of this study permit a reduction in the amount of the feldspar used, a relatively expensive raw material, and consequently reduces the cost of ceramics.

One of the most important elements of furnaces, boilers and other heating units is the structure (lining), usually made of silica–alumina, basic or special refractories. The basic refractories are materials that are increasingly in demand and whose manufacturing involves necessarily the use of MgO and CaO. In this article, the description and characterization of magnesite (MgCO3) and dolomite (Mg,Ca(CO3)2) and their contribution in industrial ceramics-refractories have been reviewed.

This paper mainly focuses on the preparation of new low-cost ceramic microfiltration membrane made from natural magnesite. Firstly, local Moroccan magnesite was deeply characterized in order to understand its chemical and mineralogical composition, and its thermal behavior. It was confirmed that used natural magnesite exhibits high purity degree in terms of magnesite mineral. Next, flat magnesite membrane was fabricated via uniaxial pressing and sintering methods. The effect of sintering in the range 900−1200 °C on morphology, porosity, pore size, permeability and mechanical strength was investigated. Based on experimental results, the optimized membrane (sintered at 1100 °C) has a porosity of 48.15 %, a pore size of 1.12 μm, a water permeability of 922 L h−1 m-2 bar-1 and a mechanical strength of 6.1 MPa. Finally, the optimized magnesite membrane was subjected to filtration of industrial textile wastewater in order to evaluation its performance as microfiltration membrane. Importantly, experimental results are clearly demonstrated that magnesite membrane effectively clarifies textile wastewater. It was showed that turbidity and chemical oxygen demand removals could achieve 99.9 and 69.7 %, respectively.

In this article, the elaboration and the characterization of silica-alumina refractory have been reviewed. Refractory oxides encompass a broad range of unary, binary, and ternary ceramic compounds that can be used in structural, insulating, and other applications. This paper provides a historical perspective on the elaboration and the use of silica-alumina refractory, reviews applications for refractory oxides, describes typical processing routes, overviews fundamental structure–property relations, and summarizes the properties of these materials.

The present chapter focuses on the scientific and technical research on clay-based nanocomposites. It begins with an introduction reminding the definition of clay nanocomposites reinforcement, the history of evolution of their field of research and development, their properties and their application fields. A synthesis is then presented on the mineralogy of natural clays specifying their classification and their physicochemical properties. This synthesis also includes the geology of argillaceous rocks citing their mode of genesis and their geographical distribution according to climatic zones. The last part of this paper shows, through the example of Morocco, the spatial distribution of clay deposits and the relationship that may exist between the nature of clay minerals of a deposit and its geological context. The note ends with a brief presentation on the different techniques of purification of natural clays and their organophilic transformation to make them finally ready to be used for the preparation of nanocomposites.

Processing of mullite and alumina based refractory ceramic by unidirectional dry pressing, from two mixtures that include silica sand, pure alumina (PA) and recycled alumina (RA) is described. The samples were sintered up to 1600 °C to study the refractory properties. The fired properties of materials (firing shrinkage, water absorption, density, flexural strength, refractoriness, and SEM microstructure) were evaluated. Promising refractories materials based on mullite and alumina were obtained.

Refractory materials were elaborated from silica–alumina geomaterials related to granitoids and their direct surrounding rocks (kaolin clay and andalusite rich schist). The use of andalusite rich schist as aggregates (mean grain size: 1000–2000 μm) could improve the mechanical properties of synthesized refractory. The flexural strength increased from 39.10 to 54.16 MPa. The pyroscopic temperature increased from 1400 to 1450 °C. Thermal conductivity of the porous brick produced in this study (1.11 W/m K) showed 39% of reduction compared to initial brick of the same composition (1.83 W/m K). The thermal shock tests showed that the refractory samples have a good thermal shock resistance.