Studio geologico e tecnologico di Materi Prime Critiche per l'industria ceramica: il caso dei complessi anulari del deserto sudorientale egiziano, con enfasi sulla sienite alcalina.

Responsabili di progetto

Michele Dondi, Ali Ismail

Accordo

EGITTO - NRC - National Research Centre of Egypt

Bando

CNR-NRC 2016-2017

Dipartimento

Scienze chimiche e tecnologie dei materiali

Area tematica

Scienze chimiche e tecnologie dei materiali

Stato del progetto

Nuovo

Proposta di ricerca

The global growth of the ceramic tiles and sanitaryware industry worldwide is rapidly increasing the overall demand for fluxes. In addition, there is an overall trend towards porcelain stoneware tiles, which make a massive use of fluxes (>50% in weight of the body) and particularly the feldspathic ones [1]. In this framework, fluxes rich in alkali feldspars, like albitites and syenites, are turning into Critical Raw Materials for the ceramic industry, because of the limited number of deposits and reserves as well as their concentration in a few countries (Turkey, Norway, Canada).
In the exploration for new deposits of fluxes, it is fundamental to account for the technological innovation in the ceramic industry, which has been drastically changing the requirements for raw materials. The best approach is to merge geological and technological issues in the search for and development of new ceramic flux deposits. For this purpose, a bilateral collaboration between Egypt and Italy can be a useful test bench: Egypt has a great potential in industrial minerals and a growing tilemaking industry needing high quality fluxes; Italy has the leading technologies in mineral treatment and ceramic manufacturing. From this standpoint, the project aims at developing new fluxing materials for sanitaryware and ceramic tiles from the Egyptian Ring complexes [2,3].
The geological, petrological, mineralogical, geochemical and technological properties of feldspathic materials from these Ring complexes will be studied and their ceramic potential will be assessed in comparison with conventional fluxes for the production of ceramic tiles in Egypt and with reference to the European and Middle-Eastern markets.
The most used raw materials in traditional ceramic industries can be basically divided into three categories: plastic components (clay), fluxing components and inert filler components (quartz, sand). Fluxes are raw materials with a high amount of alkaline and alkaline-earth oxides, mainly potash and soda, which in reaction with silica and alumina, promote liquid phase formation that govern the densification and the technical performance of tiles [4,5]. Natural raw materials, such as granite, basalt, pegmatite, phonolite, nepheline syenite and perlite, are widely used by ceramic industries as flux [6-8]. The properties of the produced ceramic bodies depend to a large extent on the particle size, types, purity, relative amounts of raw materials. Furthermore, the evaluation must account for the actual manufacturing processes in ceeramic tiles and sanitaryware industries.
Several ring complexes were emplaced during the Mesozoic and are generally related to two main phases of igneous activity, the Late Jurassic-Early Cretaceous and the Late Cretaceous-Early Tertiary [2,3]. The occurrence and tectonic environments of the Egyptian alkaline ring complexes have been reviewed in the literature. Most of these ring complexes consist of several intrusive phases, with the plutonic rocks ranging from Gabbro to nepheline syenite. Associated volcanic rocks include trachytes, rhyolites, and phonolites.
RESEARCH APPROACH AND METHODOLOGY. Activities will entail: Geological Investigation and collection of Ring Complexes samples from the Eastern Desert, Egypt. Mineralogical, petrographic and geochemical characterization (XRF, polarized optical microscopy). Selection of samples for ceramic application from geological and compositional data. Technological characterization as fluxes for ceramic tiles (hot-stage microscopy, simulation of the industrial processing, technical performance). Overall data interpretation, reporting and dissemination (workshops and know how transfer to industry).
EXPECTED OUTCOMES: a global assessment of the ceramic potential of Ring complexes in Egypt based on geological characteristics, mineralogical and geochemical composition, and technological performance as flux for ceramic tiles. The replacement of fluxing materials used traditionaly in ceramic industries can be an additional output of the project.
MODE OF CO-OPERATION: in principle, geological investigations as well as minero-petrographic and geochemical characterization will be in charge of the Egyptian group while technological characterization, beneficiation treatments and simulation of the industrial ceramic processing will be in charge of the Italian group. Extensive discussion is expected about feedback from activities, sample selection, data interpretation and final outcomes of the project.
REFERENCES
[1] Dondi M., Raimondo M., Zanelli C., Clays and bodies for ceramic tiles: reappraisal and technological classification. Applied Clay Science, 96 (2014) 91-109.
[2] Serencsits, C. McC. Faul, H. Roland, K.A. Hussein, A.A. Lutz, T.M.: Alkaline ring complexes in Egypt, their ages and relationship in time, J Geophys Res 86, (1981) 3009-3013.
[3] El-Ramly, M.F. Hussein, A. A. A.: The ring complexes of the Eastern Desert of Egypt, J Afr Earth Sci 3, (1985) 77-82.
[4] Dondi, M. Guarini, G. Venturi, I.: Assessing the feasibility of feldspathic fluxes for ceramic tiles by hot stage microscope, Industrial-Ceramics, 21 (2) (2001) 67-73.
[5] Zanelli C., Guarini G., Raimondo M., Dondi M., The vitreous phase of porcelain stoneware: composition, evolution during sintering and physical properties. Journal of Non-Crystalline Solids, 357 (2011) 3251-3260.
[6] McLemore V. (2006). Nepheline Syenite. In: Industrial minerals & rocks. Society for mining, metallurgy and exploration, USA.
[7] Abadir, M. F. Sallam, E. H. Bakr, I. M.: Preparation of porcelain tiles from Egyptian raw materials, Ceramics International 28 (2002) 303-310.
[8] Salem, A., Jazayeri, S.H., Rastelli, E., Timellini, G.: Dilatometric study of shrinkage during sintering process for porcelain stoneware body in presence of nepheline syenite. J Mater. Process Technol. 209 (2009) 1240-1246.

Obiettivi della ricerca

The aim of the project is to assess the potential for industrial minerals and to develop new ceramic fluxes. It will be pursued by studying the geologic setting and the occurrence of ring complexes in Egypt, especially in the Eastern Desert, and by investigating the composition, technological behavior and beneficiation paths. Mineralogical and chemical composition and technological behavior of the collected rock samples will be used to classify and select the raw materials for ceramic application, particularly ceramic tiles.
The ceramic industry depends essentially on common minerals such as clays, quartz and feldspars. These raw materials are frequently classified according to their function in the body as clays, filler (quartz) and flux (feldspar), however recently there is growing need for uses more suitable low cost fluxes, especially those of low temperature vitrification mixes. In particular, the aim of this work is to use Egyptian raw materials in order to produce different types of tiles that could satisfy the level required by the standards.

Ultimo aggiornamento: 07/11/2025