The mineralogical, chemical, physical and thermal analyses of the representative clays from North Africa (Algeria, Morocco and Tunisia) have been studied for their potential use in traditional ceramic industry. The clay fractions of the Moroccan and Algerian clays are essentially composed of illite (38 and 21%, respectively) and kaolinite (17 and 12%, respectively) as predominant minerals, with subordinate I/Sm mixed-layer (10 and 3%, respectively). The non-clay minerals are quartz, calcite, dolomite and occasionally plagioclase and haematite. Tunisian clays are composed of similar proportions of kaolinite (15%), smectite (15%), illite (12%) and palygorskite (9%), whereas their associated minerals are quartz (30%), calcite (15%) and rarely plagioclase (4%). The chemical data show agreement with estimated mineralogical compositions. All the samples contain large amounts of iron (>5.6%) and earth-alkaline oxides (>6.9%), and high values of LOI (>12%). Algerian clays show high plasticity (PI = 40%), requiring particular attention and careful temperature control during drying to avoid the deformation and the formation of cracks in the ceramic bodies, whereas the Tunisian and Moroccan clays (PI = 18% and 16%, respectively) show acceptable behaviour in shaping and drying. The average grain-size distribution demonstrates a substantial amount of the silt and clay fractions in raw materials which are therefore suitable for easy shaping of paste without any special need for further adjustments. Indeed, the amount of fraction upper 63 µm is lower less than 2%. The main transformations during firing are influenced by the abundance of components such as Fe2O3, CaO, MgO, K2O and Na2O and observed above 1000°C with the appearance of new crystalline phases, especially mullite, spinel, plagioclase, diopside and haematite. The technical parameters of fired pieces (firing shrinkage, water absorption and flexural strength) fall within the ceramic international standards (ISO).
AnceyC.2007. Plasticity and geophysical flows: a review.J Non-Newtonian Fluid Mech. 142:4–35.
2.
AzzouzH, AlouaniR, TligS.2011. Mineralogical characterization of ceramic tiles prepared by a mixture of Cretaceous and Mio-Pliocene clays from Tunisia: factory and laboratory product.Ceram Soc Jpn. 119:93–100.
3.
BaccourH, MedhioubM, JamoussiF, MhiriT.2009. Influence of firing temperature on the ceramic properties of Triassic clays from Tunisia.J Mater Process Technol. 209:2812–2817.
4.
BaccourH, MedhioubM, JamoussiF, MhiriT, DaoudA.2008. Mineralogical evaluation and industrial applications of the Triassic clay deposits, southern Tunisia.Mater Charact. 59:1613–1622.
5.
BainAJ.1987. Composition and properties of clay used in various fields of ceramics. Part II.Ceramic Forum International. 63:44–84.
6.
BainJA, HighlyDE.1978. Regional appraisal of clay resources challenge to the clay mineralogist. In: MortlandM.M., FaxmerV.C., editors, Proc. Int. Clay. Conf. Amsterdam: ElsevierSage UK: London, England; p. 437–446.
7.
BeaulieuJ.1979. Identification géotechnique des matériaux argileux naturels par la mesure de leur surface au moyen du bleu de méthylène. Thèse 3me cycle. Univ. OrsaySage UK: London, England.
8.
BennourA, MahmoudiS, SrasraE, BoussenS, HatiraN.2015b. Composition, firing behavior and ceramic properties of the Sejnène clays (northwest Tunisia).Appl Clay Sci. 115:30–38.
9.
BennourA, MahmoudiS, SrasraE, HatiraN, BoussenS, OuajaM, ZargouniF.2015a. Identification and traditional ceramic application of clays from the Chouamekh region in south-eastern Tunisia.Appl Clay Sci. 118:212–220.
10.
BergayaF, ThengBKG, LagalyG.2006. Developments in Clay Science. Handbook of Clay Science, 1. Amsterdam: ElsevierSage UK: London, England. 1248 p.
11.
CarreteroMI, DondiM, FabbriB, RaimondoM.2002. The influence of shaping and firing technology on ceramic properties of calcareous and non-calcareous illitic–chloritic clays.Appl Clay Sci. 20:301–306.
12.
CasagrandeA.1947. Plasticity chart for the classification of cohesive soils.Trans Am Soc Civ Eng. 73:783–811.
13.
DaoudiL, ElboudourEH, SaadiL, AlbizaneA, BennazhaJ, WaqifM, ElouahabiM, FagelN.2014. Characteristics and ceramic properties of clayey materials from Amezmiz region (Western High Atlas, Morocco).Appl Clay Sci. 102:139–147.
14.
DondiM.1999. Clay materials for ceramic tiles from the Sassuolo District (Northern Apennines, Italy). Geology, composition and technological properties.Appl Clay Sci. 15:337–366.
15.
DondiM, MariarosaR, ZanelliC.2014. Clays and bodies for ceramic tiles: reappraisal and technological classification.Appl Clay Sci. 96:91–109.
16.
El OuahabiM, DaoudiL, FagelN.2014. Mineralogical and geotechnical characterization of clays from northern Morocco for their potential use in the ceramic industry.Clay Mineral. 49:1–17.
17.
El OuahabiM, DaoudiL, HatertF, FagelN.2015. Modified mineral phases during clay ceramic firing.Clays Clay Miner. 63:404–413.
18.
EscaleraE, TegmanR, AnttiML, OdénM.2014. High temperature phase evolution of Bolivian kaolinitic–illitic clays heated to 1250 °C.Appl Clay Sci. 101:100–105.
19.
FerrariS, GualteriAF.2006. The use of illitic clays in the production stoneware tile ceramics.Appl Clay Sci. 32:73–81.
20.
González-GarcíaF, Romero-AcostaV, García RamosG, González RodríguezM.1990. Firing transformations of mixtures of clays containing illite, kaolinite and calcium carbonate used by ornamental tile industries.Appl Clay Sci. 5:361–375.
21.
GrimRE.1962. Applied clay mineral science. New York: N.Y.Sage UK: London, England (422 pp).
22.
HajjajiM, MezouariH.2011. A calcareous clay from Tamesloht (Al Haouz, Morocco): properties and thermal transformations.Appl Clay Sci. 51:507–510.
23.
ISO 10545-2.1995. Determination of dimensions and surface quality. Part 2. Edition 1.
24.
ISO 10545-3.1995. Ceramic tiles. Part 3: Determination of water absorption, apparent porosity, apparent relative density and bulk density. Edition 1.
25.
ISO 10545-4.2004. Ceramic tiles. Part 4: Determination of modulus of rupture and breaking strength. Edition 2.
26.
KhalfaouiA, HajjajiM.2009. A chloritic-illitic clay from Morocco: temperature–time–transformation and neoformation.Appl Clay Sci. 45:83–89.
27.
KlaarenbeekFW.1961. The development of yellow colours in calcareous bricks.Trans Br Ceram Soc. 60:739–771.
28.
KreimeyerR.1987. Some notes on the firing colour of clay bricks.Appl Clay Sci. 2:175–183.
29.
LCPC.1987. Limites d'Atterberg, limite de liquidité, limite de plasticité. Méthode d'essai n°19, Laboratoire Central des Ponts et Chaussées. 26 pp.
30.
MahmoudiS, BennourA, MeguebliA, SrasraE, ZargouniF.2016. Characterization and traditional ceramic application of clays from the Douiret region in south Tunisia.Appl Clay Sci. 127–128(128):78–87.
31.
MahmoudiS, BennourA, SrasraE, ZargouniF.2017. Characterization, firing behavior and ceramic application of clays from the Gabes region in south Tunisia.Appl Clay Sci. 135:215–225.
32.
MahmoudiS, SrasraE, ZargouniF.2008. The use of Tunisian Barremian clay in the traditional ceramic industry: optimization of ceramic properties.Appl Clay Sci. 42:125–129.
33.
MahmoudiS, SrasraE, ZargouniF.2010. Firing behaviour of the lower Cretaceous clays of Tunisia.J Afr Earth Sci. 58:235–241.
34.
MahmoudiS, SrasraE, ZargouniF.2014. Composition and ceramic properties of carbonate-bearing, illitic clays from north-eastern Tunisia.Arab J Sci Eng. 39:5729–5737.
35.
MeirLP, NueschR.1999. The lower cation exchange capacity limit of montmorillonite.J Colloids Interfaces Sci. 217:77–85.
36.
ModestoC, BernardinAM.2008. Determination of clay plasticity: indentation method versus Pfefferkorn method.Appl Clay Sci. 40:15–19.
PardoF, MeseguerS, JordánMM, SanfeliuT, GonzálezI.2011. Firing transformations of Chilean clays for the manufacture of ceramic tile bodies.Appl Clay Sci. 51:147–150.
39.
ProustC, JullienA, ForestierL.2004. Determination indirecte des limites d'Atterberg par gravimétrie dynamique.Compt Rendus Geosci. 335:175–183.
40.
SahnouneF, ChegaarM, SahebN, GoeuriotP, ValdiviesoF.2008. Algerian kaolinite used for mullite formation.Appl Clay Sci. 38:304–310.
41.
SantosPS.1989. Ciência e Tecnologia de Argilas, 2d Ed., vol.1, edited by Edgar Blucher, São Paulo, 66pp.
42.
SaqqaWA, DwairiIM, AkhalHM.1995. Sedimentology, mineralogical evaluation and industrial applications of the Pleistocene AL1-Y Amaniyyah clay deposits, near ‘Aqaba, southern Jordan.Appl Clay Sci. 9:443–458.
43.
SedmaleG, SperbergaI, SedmalisU, ValanciusZ.2006. Formation of high-temperature crystalline phases in ceramic from illite clay and dolomite.J Eur Ceram Soc. 26:3351–3355.
44.
ŚrodońJ.1981. X–Ray diffraction of randomly interstratified illite smectite in mixtures with discrete.Clay Miner. 16:297–304.
45.
StepkowskaET, JefferisSA.1992. Influence of microstructure on firing colour of clays.Appl Clay Sci. 6:319–342.
46.
StrazzeraB, DondiM, MarsigliM.1997. Composition and ceramic properties of Tertiary clays from southern Sardinia (Italy).Appl Clay Sci. 12:247–266.
47.
TrindadeMJ, DiasMI, CoroadoJ, RochaF.2009. Mineralogical transformations of calcareous rich clays with firing: A comparative study between calcite and dolomite rich clays from Algarve, Portugal.Appl Clay Sci. 42:345–355.
48.
TrindadeMJ, DiasMI, CoroadoJ, RochaF.2010. Firing tests on clay-rich raw materials from the Algarve basin (southern Portugal): study of mineral transformations with temperature.Clays Clay Miner. 58:188–204.
49.
WattanasiriwechD, SrijanK, WattanasiriwechS.2009. Vitrification of illitic clay from Malaysia.Appl Clay Sci. 43:57–62.
50.
WinklerHGF.1954. Bedeutung der Korngrössenverteilung und des mineral-bestandes von Tonen für die Herstellung grobkeramischer Erzeugnisse.Ber DKG. 31:337–343.
51.
YuHS, KhongC, WangJ.2007. A unified plasticity model for cyclic behaviour of clay and sand.Mech Res Commun. 34:97–114.
52.
ZaiedH-B, AbidiF R, Slim-ShimiN, SomarinAK.2015. Potentiality of clay raw materials from Gram area (northern Tunisia) in the ceramic industry.Appl Clay Sci. 112:1–9.
