8/19/2019 1-s2.0-S0169131709003524-main_2.pdf

1/6

Ceramic behaviour of  ve Chilean clays which can be used in the manufacture of ceramic tile bodies

S. Meseguer a, F. Pardo a, M.M. Jordan b,⁎, T. Sanfeliu a, I. González c

a Unit of Applied Mineralogy, Department of Agrarian Sciences and Environment , University Jaume I, Campus de Riu Sec s/n. 12080 Castellón, Spainb Department of Agrochemistry and Environment, University Miguel Hernández, Elche. Avda. de la Universidad s/n. 03202 ELCHE Alicante, Spainc Departamento de Industria. Universidad Tecnológica Metropolitana. Avda. José Predro Alexandre s/n. Macul. Santiago, Chile

a b s t r a c ta r t i c l e i n f o

 Article history:Received 30 July 2009

Received in revised form 23 November 2009

Accepted 25 November 2009

Available online 13 December 2009

Keywords:

Chile

Industrial clays

Ceramic tiles

Technological behaviour

This study is focussed on the behaviour of ceramic clays from Chile which has an important local ceramicindustry. Five deposits of clays with industrial application have been studied. The clays come from San

Vicente de Tagua-Tagua (SVTT), Litueche (L), Las Compañías  –  Río Elqui (LC), La Herradura  –  Coquimbo (LH)

and Monte Patria  –  Coquimbo (MP). The chemical and mineralogical compositions of clays were determined

by X-ray   uorescence (XRD) and X-ray diffraction (XRD), respectively. Also, the plasticity index (PI) was

measured for each sample. The chemical and mineralogical compositions of samples differ considerably. Test

samples have been prepared by pressing and   ring in the range of 800–1150 °C. Linear contraction (LC),

water absorption capacity (WAC) and thermodilatometric analysis (TDA) were done in order to characterize

clays after   ring. A considerable decrease in the WAC coinciding with the beginning of vitrication, is

observed between 1050 and 1100 °C. At 1150 °C the porosity of the tile bodies decreases signicantly and the

tile bodies became earthenware. All studied clays seem to be easily adaptable to a correct dry pressing

ceramic process. In particular, illite–kaolinite-rich samples show the best behaviour. Samples SVTT are

suitable for the production of fast  ring vitreous pieces. L samples present the highest refractory behaviour.

© 2009 Elsevier B.V. All rights reserved.

1. Introduction

It is well known that industrial clays have a complex mineralogical

composition, which makes rather dif cult the study of mineral phases

present in the raw material. Paste contraction occurs while grains are

approaching each other. Each particle in the body is separated by

water lm at the initial stages of drying ( Jeridi et al., 2008). The water

lm becomes thinner until the   “critical point”, at which the rate of 

drying and shrinkage sharply change (Dondi et al., 2002), and the

particles come into contact occupying the open space left by the

released water. Shrinkage tends to increase as vacuum volume rises,

and this seems to explain partially why shrinkage is lower when

pressing load increases ( Jeridi et al., 2008). During the ring process a

series of transformations occur, which will be decisive to achieve the

nal properties of the ceramic products (González-García et al., 1990;

 Jordan et al., 1999). Through the ceramic process, once the crystalline

structures of minerals exceed their stability limits, they are partially

decomposed while simultaneously others are being formed. The

destruction of the pre-existing structure does not occur instanta-

neously ( Jordan et al., 1999). The knowledge of the origin, diagenesis

and physicochemical composition of the clays is essential when

sketching out suitable compositions required for ceramic production

(Sanfeliu and Jordan 2009).

The relationship between the mineralogy of the raw materials and

the phase changes taking place during their sintering under different

conditions have been examined (Daskshama et al., 1992; Jordan et al.,

1999 and Jordan et al., 1999). Between 900 and 1000 °C a sintering

process takes place, which consists in the aggregate compaction of 

particles. This process is not complete, so the ceramic tile bodies are

still quite porous. Towards 1000 °C the larger pores are seen to

increase (between 1 and 10 μ m). This phenomenon coincides with the

destruction of illites, chlorites and their re-crystallisation into quartz

and spinel principally ( Jordan et al., 2008).

Ceramics industry in Chile starts between 1950 and 1960 as a

result of the optimistic and positive attitude of a country, which has

made great effort to implement a small industry located around

Santiago de Chile. The continuous improvement of the initial modest

facilities using primitive methods of manufacture has been the result

of joint efforts of various companies and factories that together

implemented new and improved manufacturing techniques. These

enabled producing from theclay gres stonewareto themost advanced

ceramic products for varied uses.

There is no previous study about these non exploited clay deposits

in the region and it is therst time that the applicability of these clays

as raw materials for ceramic industry has been tested. The main

objective of this paper is the study of the chemical –mineralogical

Applied Clay Science 47 (2010) 372–377

⁎  Corresponding author. Tel.: +34 966658416; fax: +34 966658340.

E-mail address: manuel.jordan@umh.es (M.M. Jordan).

0169-1317/$   –  see front matter © 2009 Elsevier B.V. All rights reserved.

doi:10.1016/j.clay.2009.11.056

Contents lists available at  ScienceDirect

Applied Clay Science

 j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / c l a y

mailto:manuel.jordan@umh.eshttp://dx.doi.org/10.1016/j.clay.2009.11.056http://www.sciencedirect.com/science/journal/01691317http://www.sciencedirect.com/science/journal/01691317http://dx.doi.org/10.1016/j.clay.2009.11.056mailto:manuel.jordan@umh.es

8/19/2019 1-s2.0-S0169131709003524-main_2.pdf

2/6

compositions and technological behaviour that allows the evaluation

of the applicability of the clay deposits studied.

2. Materials and methods

Five deposits of Chilean clays which canbe used in the formulation

of ceramic pastes were selected (Fig. 1). The clays come from San

Vicente de Tagua-Tagua (SVTT), Litueche (L) in the VI Region of Chile,

and Las Compañías  –

 Río Elqui (LC), La Herradura  –

 Coquimbo (LH)and Monte Patria   – Coquimbo (MP) from the IV Region of Chile.

The Tagua-Tagua basin in Chile (VI Region) was studied by Varela

(1976) and Nuñez et al. (1994). The Formation   “Laguna de Taguata-

gua” had a lagoon origin and it was form during the Würm glaciation.

Meseguer et al. (2009c)  studied the geology and mineralogy of the

Upper Tertiary white clays from Litueche (VI Region). The geology of 

Elqui basin (IV Region) presents a wide variety of Units from

Palaeozoic to Tertiary. Studied clays (LC) belong to alteration

hydrothermal zones of the Inernillo Unit (Lower Miocene).

The geology of the Coquimbo area (IV Region) comprises units

ranging in age from Palaeozoic to Tertiary. The Paleozoic rocks crop

out along a narrow belt in thecoast and mostly consist of monotonous

mica schists series. These rocks were partially covered by Pliocene to

Quaternary marine sedimentary rocks. Eastward from the coast the

geology is dominated by volcaniclastic, volcanic and sedimentaryunits of lower Cretaceous age. The studied clays (LH and MP) belong

to these sedimentary units.

Samples of each clay deposit were collected. They were oven-dried

at 110 °C until constant mass and then grounded with a hammer mill

to null residue in the 630 µm control sieve, following the normal

practice in ceramic laboratories (Meseguer et al., 2009a). Eight

Fig. 1. Location of the studied clay deposits. Legend: A: Monte Patria (MP); B: La Herradura (LH); C: Las Compañias (LC); D: Litueche (L); E: San Vicente de Tagua Tagua (SVTT).

373S. Meseguer et al. / Applied Clay Science 47 (2010) 372– 377 

8/19/2019 1-s2.0-S0169131709003524-main_2.pdf

3/6

samples foreachdeposit were analysed to know themineralogicaland

chemical compositions (average values are shown and discussed). A

representative sample of each deposit was selected for ceramic

behaviour tests.

The mineralogical analysis was carried out by X-ray diffraction

(XRD) using a Siemens D-5000 diffractometer, CuKα radiation, both

on powder (bulk samples) and oriented aggregates (natural and

treated with ethylene glycol and heated to 550 °C for 2 h) of the clay

fraction obtained following the criteria expressed in   Moore and

Reynolds (1997). A semi-quantitative analysis was carried out

following Jordan et al.'s (1999) methodology.

The chemical analysis was obtained by X-ray uorescence (Bruker

S4 Pioneer) using the conventional techniques (Meseguer et al.,

2009b).

The Pfefferkon method was used to determine the plasticity index

(PI). After moistening to obtain a shaping paste, the drying capacity of 

the clays was determined by using a barelattograph to trace the Bigot

curve.

To simulate industrial pressing conditions, the clays were moist-

ened by hand mixed suf ciently and sieved (1 mm) until homoge-

neous agglomerates with 6% of water were obtained. They were left to

rest for24 h andthen pressed (300 kg/cm2, 80×40×5 mm) byusing a

laboratory press. The pieces were  nally heated to 800, 850, 900,950,

1000, 1050, 1100 and 1150 °C, keeping at the maximum temperaturefor 35 min.

The linear contraction (LC) was determined following the con-

ventional techniques. The water absorption capacity (WAC) was

determined in  red clay pieces following the ISO-10545-3.

Thermodilatometric analysis (TDA) was carried out using a hori-

zontal pushrod dilatometer Bähr model DIL 804 with a heating rate of 

10°K min−1; usingα-Al2O3 as inert substance. This technique consists

in measuring the length of a sample as a function of the temperature,

allowing the study of the sintering process.

3. Results and discussion

 3.1. Mineralogy

The mineralogical compositions of samples differ considerably

(Table1). SVTT bulk samples consistedmainly of albiteand quartz, and

contain K-feldspars, hematite, kaolinite and chlorite in minor

amounts. Illite/muscovite, kaolinite and palygorskite were the dom-

inant phases in SVTT clay fraction. Other components found in lesser

quantities in this fraction were quartz and albite.

In LC bulk samples albite, quartz and chlorite were the dominant

phases; tremolite, hematites and kaolinite were present in lesser

quantities. In LC clay fraction the mineral phases found were: illite/

muscovite, chlorite, kaolinite, albite and traces of quartz, pyrophyllite,

sepiolite, vermiculite and palygorskite.

The main phases found in LH bulk samples were quartz, albite,

K-feldspar, and calcite. The main phases in clay fraction were calcite,

kaolinite, chlorite and illite/muscovite. Hematite and sepiolite were

found in trace amounts in bulk samples and clay fraction, respectively.

Albite, quartz, talc, kaolinite and chlorite were the main phases

found in MP bulk samples. Other minerals found in minor quantities

were K-feldspars, calcite, hematite and tremolite. The main clay

minerals found in MP clay fraction were kaolinite, chlorite and

montmorillonite. Other minor phases in the clay fraction are quartz

and calcite.

Finally, themineral composition of theL samples, both in bulk rock

and clay fraction, consisted of quartz, K-feldspar and kaolinite with a

small amount of of illite/muscovite. As pointed out by many authors

( Jordan et al., 1999, 2001, 2009, among other), the mineralogical

differences in the raw material have great inuence in the behaviour

of ceramic pastes, in respect to their rheological and thermal

properties, as well as the porous structure of the  red products.

 3.2. Chemical composition

The chemical composition (Table 2) of most samples showed high

iron content (5–11%), responsible for the reddish colour developed

upon   ring, except for the L sample that has very low (b1%) iron

content. SVTT and LH showed the highest relative amounts of alkalis

(Na2O +K2O), explaining why this sample matures at relatively lowtemperatures ( Jeridi et al., 2008). By contrast, the relatively higher

amounts of carbonates in LH and MP clay samples might explain the

delay in the sintering process. Decarbonation is a strongly endother-

mic reaction that generates high volume of gas, leading to expansive

reactions (Cultrone et al., 2004). The L sample is a carbonate-free

samplerichest in silica. Higher loss on ignition valueswas observed for

the carbonate-rich LH and MP samples, suggesting the contribution of 

decarbonation reactions.

 Table 2

Chemical analysis (%mass, dry). LOI: loss on ignition.

% SVTT LH LC MP L  

SiO2   59.1 57.4 54.8 46.0 68.8Al2O3   17.1 14.3 16.4 16.1 20.6

Na2O 4.01 3.56 4.51 1.92 0.32

K2O 2.85 3.00 0.93 1.37 4.46

CaO 1.73 6.17 2.57 7.71 0.10

MgO 1.45 1.89 3.63 5.08 0.15

Fe2O3   8.05 5.41 10.70 11.00 0.99

TiO2   1 .10 0.76 0.90 0.87 0.54

MnO 0.17 0.07 0.11 0.23 0.01

P2O5   0.27 0.34 0.10 0.16 0.03

SO3   – –   0,09 0,04   –

Rb2O 0.01 0.01   –   0.01 0.02

SrO 0.08 0.05 0.02 0.03   –

Y 2O3   – – – –   0.01

ZrO2   0.03 0.03 0.02   –   0.13

BaO 0.09   – – –   0.06

CuO   – – –   0.01   –

L.O.I. 4.45 7.66 6.09 10.46 4.78

 Table 1

Mineralogical composition of the studied clays.

Bulk rock Clay fraction

Sample Q Ab FdK   Cc Hem I/M K Cl Talc Tre Q Cc Ab FdK   I/M K Cl Se Pa Py V Mont

SVTT +++ ++++ +   −   + (+) + (+)   − −   (+)   −   (+)   −   +++ +++ + + ++   − − −

LC ++ ++++   − −   +   −   + ++ + + (+)   −   +   −   ++ ++ ++ (+) (+) (+) (+)   −

LH ++++ +++ ++ ++ (+)   − − − − − −   +   − −   ++ ++ ++ (+)   − − − −

MP +++ ++++ + + +   −   ++ ++ +++ + (+) (+)   − − −   +++ +++   − − − −   ++

L ++++   −   +++   − −   (+ ) ++   − − −   +++   − −   ++ + ++++   − − − − − −

Legend: Q: quartz; Ab: albite, Fdk: K-feldspar; Cc: calcite; Hem: hematite; I/M: illite/muscovite; K: kaolinite; Cl: chlorite; T: talc; Tre: tremolite; Se: sepiolite; Pa: palygorskite;

Py: pyrophyllite; V: vermiculite; Mont: montmorillonite; ++++ (N20%); +++ (N 15%); ++ (N 10%); + (N 5%); (+) present (b5%); − not present.

374   S. Meseguer et al. / Applied Clay Science 47 (2010) 372– 377 

8/19/2019 1-s2.0-S0169131709003524-main_2.pdf

4/6

8/19/2019 1-s2.0-S0169131709003524-main_2.pdf

5/6

Fig. 4. Thermodilatometric analysis (TDA). Change in length vs temperature. Legend: A: Monte Patria (MP); B: La Herradura (LH); C: Las Compañias (LC); D: Litueche (L); E: San

Vicente de Tagua Tagua (SVTT).

Fig. 3.   Evolution of linear contraction (LC) and water absorption capacity (WAC) vs temperature. Legend: A: Monte Patria (MP); B: La Herradura (LH); C: Las Compañias (LC);

D: Litueche (L); E: San Vicente de Tagua Tagua (SVTT).

376   S. Meseguer et al. / Applied Clay Science 47 (2010) 372– 377 

8/19/2019 1-s2.0-S0169131709003524-main_2.pdf

6/6

The variations observed in the water absorption capacity are

mainly due to two factors that are produced simultaneously but with

opposite effects. The  rst factor is related to the degree in which the

open porosity of the pieces diminishes due to an increase in the liquid

phase and a decrease in its viscosity. Besides reducing the porosity of 

the tile bodies, this effect partially blocks the pre-existent capillary

system (Amorós et al., 1992), which reduces the WAC even more.

Secondly, as a consequence of the micro-structural heterogeneity of 

the raw tile bodies, a progressive elimination of the smaller press wasobserved in increasing the temperature. This brings about differential

contractionsamongthe different micro-regions of thetile body, andas

a consequence,the average poresize diameterincreases. From1000 °C

upward in some pieces and from 1050 °C in others, high levels of 

sintering were reached, which became evident with the fast decrease

in WAC.

Thermodilatometric analysis (Fig. 4) showed that the behaviour of 

the clays studied was different, which was related with the mass loss

due to decarbonation ( Jeridi et al., 2008) in LH and MP samples

mainly. The thermodilatomettric curves can be classied in two

groups. One group is formed for the calcite-richsamples (LH and MP),

and the second group is formed for the rest of the samples (LC, L and

SVTT), very poor in carbonates. The ring process should therefore be

conducted with precaution by creating a low-heating rate stage in the

decarbonation zone (850–1000 °C). The general behaviours of L, SVTT

and LC were similar because the decarbonation reaction is weaker or

inexistent, due to these samples not having a calcite.

4. Conclusions

All the studied clays seem to be easily adaptable to a correct dry

pressing ceramic process. In particular, illite–kaolinite-rich samples

(LH) and kaolinite-rich samples (L) show the best ceramic behaviour

due to their ring behaviour. In mixtures with samples LH and MP the

amount of carbonates should not exceed 10% to avoid excess porosity

caused by strong decarbonation reactions. In contrast, samples SVTT

are more suitable for the production of fast  ring vitreous pieces. L 

samples present the highest refractory behaviour.Thepositive resultsobtainedin this setof preliminary tests lead us to

envisage new research programs in Chile, focused on testing these and

other raw materials on a semi-industrial scale, assessing the effective

possibility of using them as ceramic raw materials in the local ceramic

industry. Mechanical properties of these clays will be researched in the

next coming publications, as well as the respectivemicrostructures and

mineral transformations of the studied raw materials.

References

Amorós, J.L., Beltrán, A., Escardino, E., Orts, M.J., 1992. Permeabilidad al aire de soportescocidos de pavimento cerámico. Boletínde la SociedadEspañola de Cerámicay Vidrio31, 33–35.

Carretero, M.I., Dondi, M., Fabbri, B., Raimondo, M., 2002. The inuence of shaping andring technology on ceramic properties of calcareous and non-calcareous illitic–chloritic clays. Applied Clay Science 20, 301 –306.

Cultrone, G., Sebastian, E., Elerk, K., De la Torre, M.J., Cazalla, O., Rodriguez-Navarro, C.,2004. Inuence of mineralogy and   ring temperature on the porosity of bricks.

 Journal of the European Ceramic Society 24, 547–564.

Daskshama, V., Mohan, B.V., Lalithambika, M., Nair, C.G.R., 1992. Sintering studies onplastic clays. Ceramics International 18, 359–364.

Dondi, M., Marsigli, M., Ventura, I., 1998. Sensibilità all'essiccamento e caratteristicheporosimetriche delle argille italiane per laterizi. Ceramurgia 28, 1 –8.

Dondi,M., Guarini, G., Raimondo, M., Ventura, I., 2002. Orimulsion y ash inclaybricks-part 2: technological behaviour of clay/ash mixtures. Journal of the EuropeanCeramic Society 22, 1737–1747.

González-García,F., Romero-Acosta, V., García Ramos, G., González Rodríguez,M., 1990.Firing transformations of mixtures of clays containing illite, kaolinite and calciumcarbonate used by ornamental tile industries. Applied Clay Sciences 5, 361 –375.

 Jeridi, K., Hachani, M., Hajjaji, W., Moussi, B., Medhioub, M., López-Galindo, A., Kooli, F.,Zargouni, F., Labrincha, J., Jamoussi, F., 2008. Technological behaviour of someTunisian clays prepared by dry ceramic processing. Clay Minerals 43, 339 –350.

 Jordan, M.M.,Boix, A., Sanfeliu, T.,de la Fuente,C., 1999.Firingtransformationsof cretaceousclays used in the manufacturing of ceramic tiles. Applied Clay Sciences 14, 225 –234.

 Jordan, M.M., Sanfeliu, T., De la Fuente, C., 2001. Firing transformations of Tertiary claysused in the manufacturing of ceramic tile bodies. Applied Clay Science 20, 87 –95.

 Jordan, M.M., Montero, M.A., Meseguer, S., Sanfeliu, T., 2008. Inuence of   ringtemperature and mineralogical composition on bending strength and porosity of ceramic tile bodies. Applied Clay Science 42, 266 –271.

 Jordan, M.M., Martín-Martín, J.D., Sanfeliu, T., Gómez-Gras, D ., De la Fuente, C., 2009.Mineralogy and   ring transformations of Permo–Triassic clays used in themanufacturing of ceramic tile bodies. Applied Clay Science 44, 173 –177.

Marsigli, M., Dondi, M., 1997. Plasticità delle argille italiane per laterizi e previsione delloro comportamento in foggiatura. L'Industria dei Laterizi 46, 214–222.

Meseguer, S., Jordan, M.M., Sanfeliu, T., 2009a. Use of mine spoils from Teruel coalmining district. Environmental Geology 56, 845–853.

Meseguer, S., Sanfeliu, T., Jordan, M.M., 2009b. Classication and statistical analysis of mine spoils chemical composition from Oliete Basin (Teruel. NE Spain). Environ-mental Geology 56, 1461–1466.

Meseguer, S., Sanfeliu, T., Pardo, F., González, I., Jordan, M.M., de la Fuente, C., 2009c.Prospección geológica, mineralogía y ceramicidad de arcillas blancas de Litueche,VI Región de Chile. Macla 11, 125–126.

Moore,D.M., Reynolds Jr.,R.C., 1997. X-raydiffraction andthe identication and analysisof clay minerals. Chapter 6. Sample preparation Techniques for clay minerals.Preparing the Oriented Clay Mineral Aggregate. Oxford University Press, p. 214.

Nuñez, L., Varela, J., Casamiquela, R., Schiappacasse, V., Niemeyer, H., Villagran, C., 1994.

Cuencade Taguatagua en Chile : el ambiente delPleistocenosuperiory ocupacioneshumanas. Revista Chilena de Historia Natural 67, 503–519.Ratzemberger,H., 1990.An accelerated methodfor the determinationof dryingsensitivity.

Ziegelindustrie International 43, 348–354.Sanfeliu, T., Jordan, M.M., 2009. Geological and environmental management of ceramic

clay quarries: a review. Environmental Geology 57, 1613–1618.Tari, G., Ferrerira, J.M.F., 1997. Bigot's curves: a practical and ef cacious method to

characterize unred compacts obtained by casting. Ceramurgia 27, 363 –368.Varela, J., 1976. Estudio estratigráco sedimentológico de los depósitos de Laguna de

Taguatagua. Universidadde Chile, Provincia de O'Higgins. Departamento de Geología.

377S. Meseguer et al. / Applied Clay Science 47 (2010) 372– 377